Anatomy

Ashfaq UI Hassan

Implantation occurs at	6 days
Uteroplacental circulation establishes at	11–12 days
Primitive streak appears on Formed from: ectoderm	13–15th day
Angiogenesis	15th day
Closure of anterior neuropore	24 days
Embryo develops by	8 week
Fetus is	> 8 weeks

The differentiation of many different cell types is regulated through a relatively restricted set of molecular signaling pathways:

Morphogens: These are diffusible molecules that specify which cell type will be generated at a specific anatomic location and direct the migration of cells and their processes to their final destination
These Include
- Retinoic acid
- Transforming growth factor bone morphogenetic proteins (BMPs) and
- The hedgehog and the Wnt family proteins
Notch/Delta: This pathway often specifies which cell fate precursor cells will adopt
Transcription factors: This set of evolutionarily conserved proteins activates or represses downstream genes that are essential for many different cellular processes. Many transcription factors are members of the homeobox or helix-loop-helix (HLH) families. Their activity can be regulated by all of the other pathways described in this chapter
Receptor tyrosine kinases (RTKs): Many growth factors signal by binding to and activating membrane-bound RTKs. These kinases are essential for the regulation of cellular proliferation, apoptosis and migration as well as processes such as the growth of new blood vessels and axonal processes in the nervous system.

Within 1 week	Implantation
Within 2 week	Bilaminar disk
Within 3 week	Trilaminar disk Gastrulation
Within 3 week	Primitive streak begins to form Notochord forms
Within 3–8 week	Organogenesis Teratogen susceptibility maximum
Week 10	Genitalia with male and female characters

Stem cells must be able to:

Divide to produce sufficient cells
Differentiate into the cell types needed
Survive after transplant
Mesh into the surrounding tissues
Function properly for long enough to extend the recipient’s life or to improve it significantly
Avoid harming the recipient

Group A	Ch 1, 2, 3
Group B	Ch 4, 5
Group C	Ch 6, 7, 8, 9, 10, 11, 12, X
Group D	Ch 13, 14, 15
Group E	Ch 16, 17, 18
Group F	Ch 19, 20
Group G	Ch 21, 22, Y

Meckel’s Diverticulum

This true diverticulum is a remnant of the vitelline duct and often contains ectopic gastric mucosa which can cause bleeding and perforation.

The Ductus Venosus

It is a shunt that bypasses the liver and carries blood from the umbilical vein directly to the IVC. Its remnant is the ligamentum venosum.

The Ductus Arteriosus

It is a shunt that bypasses the lungs to carry blood from the pulmonary artery to the aortic arch. Its remnant is the ligamentum arteriosum.

The Urachus

Becomes the Median umbilical ligament
The 2 umbilical arteries becomes the Medial umbilical ligaments
Urachal fistula from persistent allantois

The Vitelline Duct

It is a connection with the yolk stalk and bowel, but normally obliterates during week 7 of development.

Fetal Structure	Adult Remnant
Right and left umbilical artery	Medial umbilical ligament
Left umbilical vein	Ligamentum teres
Ductus venosus	Ligamentum venosum
Foramen ovale	Fossa ovalis
Ductus arteriosus	Ligamentum arteriosum

Connects fetus and placenta
It is rich in Wharton’s jelly
Has Two arteries and one vein
Rt umbilical vein disappears, left is left
In case of single artery only, congenital anomalies should be excluded
Umbilical arteries carry deoxygenated blood
Umbilical arteries do not possess internal elastic lamina
Vas vasorum are absent in cases of umbilical vessels

Oogonia are derived from yolk sac
Germ cells are derived from yolk sac
Polar bodies are formed during oogenesis
Polar bodies are extruded 24 hours prior to ovulation

Spermatogenesis occurs at temperature lower than body temperature
Y chromosome is ACROCENTRIC
In absence of Y chromosome ovaries develop
Sperms are stored in epididymis
Length of mature human sperm is 50–60 microns

Number of Chromosomes in Cells During Gametogenesis
Primordial germ cell, oogonia, spermatogonia	46, 2N
Primary oocyte, primary spermatocyte	46, 4N
Secondary oocyte, secondary spermatocyte	23, 2N
Oocyte, spermatid, sperm	23, 1N

Biscoidal placenta: Placenta has two disks
Lobed placenta: Placenta divides into lobes
Diffuse placenta: Chorionic villi persist all around the blastocys.
Placenta succenturiate: Small part of placenta separated from the rest

6Fenestrated: Placenta has hole in center
Circumvallate: Edge of placenta covered by circular fold of deciduous

According to umbilical cord attachment:

Marginal: Marginal as well as battledore placenta refers to placenta with cord attached to margins
Furcate: Blood vessels divide before reaching the placenta
Velemantous insertion: Blood vessels are attached to amnion where they ramify before reaching the placenta

Oligohydramnios: Low level of amniotic fluid (< 400 ml) in renal agenesis
Polyhydramnios: High level of amniotic fluid (>2000 ml)
In the fourth intrauterine month the fetus begins to swallow amniotic fluid (25 to 40% of the volume) and absorbs the fluid from the upper gastrointestinal tract
The fluid is urinated back out into the amniotic pool by the fetal kidneys and a functioning bladder. Although there are maternal causes of polyhydramnios (cardiac failure, renal failure, other causes of fluid retention) and some idiopathic cases, many instances are related to the presence of fetal anomalies. These include:
Central nervous system problems such as anencephaly, which prevents normal swallowing, and any high alimentary tract obstruction that blocks the passage of the amniotic fluid and prevents its absorption such as:
- Esophageal atresia
- Pyloric atresia
- Duodenal atresia
- Maternal diabetes
Amniotic band syndrome: When bands of amniotic membrane encircle and constrict parts of fetus causing limb amputations and Craniofacial anomalies

USMLE Case Scenario

Polyhydramnios is not seen in one of the following conditions:

Esophageal atresia
Duodenal atresia
Pyloric atresia
Hirschsprung’s disease
Congenital diaphragmatic hernia

Ans. 4. Hirschsprung’s disease

Skin and most of appendages
Lens of eye
Epithelial linning of Lower half of anal canal
Epithelial lining of external auditory meatus
Epithelial lining of distal part of male urethra
Adenohypophysis

Musculoskeletal system
Cardiovascular system
Kidney, ureter
Trigone of bladder (mesonephric duct absorption)
7Posterior wall of female urethra
Posterior wall of prostatic part of male urethra
Reproductive tract except labia majora, minora and major part of prostate
Mesothelium of pleural, pericardial and peritoneal cavities
Dentine of teeth
Cornea, sclera, choroid, ciliary body and iris of eye
Somites from paraxial mesoderm

Epithelial lining of GIT
Epithelial lining of Biliary tract
Epithelial lining of Respiratory tract
Epithelial lining of vagina
Epithelial lining of auditory tube, middle ear

Glandular stage	5–17 weeks	Respiration not possible
Cannalicular stage	16–25 weeks	Respiratory bronchioles and terminal sacs form
Terminal sac stage	24 Weeks–birth	Type I and II Pneumocytes present
Alveolar stage	Birth-8 years	Respiratory bronchioles, terminal sacs, alveolar duct, alveoli↑

Embryonic Structure	Adult Structure
Truncus arteriosus	Aorta Pulmonary trunk
Bulbus cordis	Smooth part of R ventricle Smooth part of L ventricle
Primitive ventricle	Rough part of R ventricle Rough part of L ventricle
Primitive atrium	Rough part of R ventricle Rough part of Latrium
Sinus venosus	Smooth part of Ratrium Coronary sinus (Lt horn of sinus venosus) Oblique vein of left atrium

Embryonic Structure	Adult Structure
Aortic arch 1
Aortic arch 2
Aortic arch 3	Common carotid artery Internal carotid artery (proximal part)
Aortic arch 4	Rt. Subclavian artery (proximal part) Part of aortic arch Persistence leads to double aortic arch
Aortic arch 5	Regresses
Aortic arch 6	Pulmonary artery Ductus arteriosus

Ventral mesogastrium	Lesser omentum, hepatoduodenal, hepatogastric, falciform, coronary and triangular ligament of liver
Dorsal mesogastrium	Greater omentum, mesentry of small intestine, mesoappendix, sigmoid mesocolon, transverse mesocolon

Embryo	Adult structure
Ureteric Bud	Collecting duct Major/Minor Calyx Renal pelvis Ureter Epithelium of ureter from mesonephros
Metanephric Mesoderm	Renal glomerulus Bowmans capsule PCT DCT Loop of Henle Connecting tubule

Gonads	Ovary	Testis
Paramesonephric duct or Mullerian duct	Uterine tubes Uterus Cervix Hydatid of morgagni	Appendix testis
Mesonephric ‘duct’ or Wollfian duct	Appendix vesiculosa Duct of Garnier	Epididymis ductus deferens Seminal vesicles Ejaculatory ducts Appendix epididymis
Mesonephric ‘tubules’	Epoophoron Paroophoron	Efferent ductules Paradidymis
Phallus	Clitoris	Glans penis
Urethral folds	Labia minora
Genital swellings	Labia majora	Scrotum

Embryonic Structure	Female	Male
Genital ridge	Ovary	Testis
Genital swelling	L majora	Scrotum
Genital fold	L minora	Ventral aspect of penis
Genital tubercle	Clitoris	Glans penis

Iliac fossa	3rd month
Deep inguinal ring	7th month
Pass through inguinal canal	7th month
At superficial inguinal ring	8th month
Enter scrotum	9th month

Neurons of spinal posterior nerve root ganglia
Neurons of sensory ganglia
Neurons of autonomic ganglia (sympathetic ganglia)
Schwann cells
Melanocytes
Piamater and arachnoid matter
Mesenchyme of dental papillae
Cartilage cells of branchial arches
Chromaffin tissue

Albinism
Melanoma
Hirschsprungs disease
Oropharyngeal teratoma
Neurocristopathies (Cleft Lip, Cleft palate, Digeorges syndrome, Waarden burgs syndrome, Charge syndrome

Neuroblastoma
Pheochromacytoma
Carcinoid tumor
Neurofibromatosis
Medullary carcinoma thyroid

USMLE Case Scenario

A newborn boy does not pass meconium until 45 hours after his birth. Several weeks later his well educated mother complains that he has not been passing stool regularly. Anorectal manometry reveals increased internal anal sphincter pressure on rectal distention with a balloon. The patient’s disorder maybe attributed to distention with a balloon. The patient’s disorder maybe attributed to:

Defective recanalization of the colon
Failure of neural crest cells to migrate
Herniation of abdominal contents into the umbilical cord
Persistence of the proximal end of the yolk stalk
Persistence of processus vaginalis
Failure of gastrulation

Ans. 2. Failure of neural crest cells to migrate

Pharyngeal Arches are derived from Mesoderm
Pharyngeal clefts are derived from Ectoderm
Pharyngeal Pouches are derived from Endoderm

Meckels Cartilage:
- Mandible
- Malleus
- Incus
- Sphenomandibular ligament
Muscles: Muscles of mastication (Medial pterygoid and lateral pterygoid, masseter, temporalis)
Two Tensors (Tensor tympani, tensor palati)
Mylohyoid, anterior belly of digastrics

Reicherts Cartilage:
- Stapes
- Styloid process
- Smaller cornu of Hyoid Bone
- Superior surface of Hyoid Bone
- Stylohyoid ligament
Muscles of facial expression, Stapedius, Stylohyoid, Posterior Belly of Digastric
Platysma

Greater cornu of Hyoid Bone
Stylopharyngeus muscle

Cartilages of larynx
Intrinsic muscles of larynx and pharynx

Mandibular nerve Ist arch
Facial nerve 2nd arch
Glossopharyngeal nerve 3rd arch
Superior laryngeal nerve 4th arch
Reccurent laryngeal nerve 6th arch

Abnormal formation of pharyngeal arch
Faulty migration of neural crest cells

Hypoplasia of the facial bones: An underdeveloped mandibular and zygomatic bone leading to a small and malformed jaw
Ear anomalies: Consist small, rotated or even absent ears with or without bilateral stenosis or atresia of the external auditory canals
Eye problems: Varying from colobomata of the lower eyelids and aplasia of lid lashes to short, downslanting palpebral fissures and missing eyelashes. Vision loss can occur and is associated with strabismus, refractive errors, and anisometropia
Cleft palate
Airway problems: Which are often results of mandibular hypoplasia
Dental anomalies: Consist in tooth agenesis, enamel disformaties and malplacement of the maxillary first molars.

Nasal deformity
High-arched palate
Coloboma of the upper lid
Ocular hypertelorism
Choanal atresia
Macrostomia
Preauricular hair displacement

Pharyngeal Pouch	Adult Structure
Pharyngeal Pouch 1	Epithelial linning of Auditory tube/Middle ear
Pharyngeal Pouch 2	Palatine tonsil
Pharyngeal Pouch 3	Inferior parathyroid and Thymus
Pharyngeal Pouch 4	Superior parathyroid and Ultimobranchial body Para follicular cells are derived from ultimobranchial body

Pharyngeal Cleft/Groove	Adult Structure
1	External linning of External auditory meatus
2, 3, 4	Obliterated

Cleft Lip:

Failure of Fusion of Maxillary and Medial Nasal Process
Usually associated with cleft palate. (Commonest)
Midline cleft lip is due to failure of fusion of two medial nasal processes
Cleft Palate: Failure of fusion of lateral palatine process, nasal septum and median palatine process (occasional)

Unilateral cleft lip. Also called Harelip	Failure of fusion of medial nasal process with maxillary process
Midline defect of upper lip	Defect in development of lowermost part of frontonasal process
Midline defect of lower lip	Defective fusion of mandibular processes
Microstomia	Excessive fusion of maxillary and mandibular processes
Macrostomia	Inadequate fusion of maxillary and mandibular processes
Oblique facial cleft	Non fusion of maxillary and lateral nasal process

1st pharyngeal arch forms ant 2/3
3 rd and 4 th arch forms post 1/3
Muscles of tongue develop from occipital myotomes
Muscles of tongue are both smooth and skeletal muscles
Muscles of tongue are supplied by hypoglossal nerve
Safety muscle of tongue is genioglossus

Tip of tongue drains to submental lymph nodes
Posterior 1/3 of tongue is supplied by glossopharyngeal nerve
Pain of cancer base of tongue is also reffered to ear through glossopharyngeal nerve
Circumvallate pappilae of tongue are supplied by glossopharyngeal nerve

Anterior 2/3 of tongue develops from lingual swellings and tuberculum impar
Anterior 2/3 of tongue is supplied by chorda tympani (FACIAL) (taste)
Anterior 2/3 of tongue is supplied by lingual nerve (general)
Anterior 2/3 of tongue drains into submandibular lymph nodes
Posterior 1/3 of tongue develops from hypobranchial eminence
Posterior 1/3 of tongue is supplied by glossopharyngeal nerve (taste)
Posterior 1/3 of tongue is supplied by glossopharyngeal nerve (general)
Posterior 1/3 of tongue drains into jugulo omohyoid lymph nodes
Tip drains into submental lymph nodes

Has nonkeratinized squamous epithelium
It is an endodermal structure
Rests on superior constrictor muscle of pharynx
Vagus supplies tonsil
Main nerve supply is the glossopharyngeal nerve
Lymph drains into jugulo digastric nodes
Arterial supply:
- Ascending palatine
- Descending palatine and
- Ascending pharyngeal artery supply tonsils

Septum transversum
Pleuroperitoneal folds
Body wall
Dorsal mesentry of esophagus

Spleen

It is unique in respect to its development within the gut. While most of the gut viscera are endodermally derived (with the exception of the neural-crest derived suprarenal gland), the spleen is derived from mesenchymal tissue. Specifically, the spleen forms within, and from, the dorsal mesentery.

Pancreas

The pancreas develops between the layers of the mesentery from dorsal and ventral pancreatic buds of endodermal cells, which arise from the caudal or dorsal part of the foregut. Most of the pancreas is derived from the dorsal pancreatic bud. The larger dorsal pancreatic bud appears first and develops a slight distance cranial to the ventral bud.

The liver, gallbladder and the biliary duct system arise as a ventral outgrowth (hepatic diverticulum) from the caudal foregut in the 4th week

This hepatic diverticulum extends into septum transversum, a mass of splanchnic mesoderm between the developing heart and the midgut
The septum transversum forms the ventral mesentery in this region. This double-layered membrane gives rise to the lesser omentum and the falciform ligament
The superior layers of the coronary and left triangular ligaments meet and continue as a ventral mesentery attached to the ventrosuperior aspect of the liver

Gallbladder arises from pars cystica (from the hepatic bud)

The nervous system develops from the neural plate which appears at the beginning of the third week as thickening of the ectoderm
Its lateral edges soon elevate to form the neural folds
With further development, the neural folds continue to elevate, and form a tube known as neural tube
The neural tube has an enlarged cranial part that forms the brain, and a narrow caudal part that becomes the spinal cord
The wall of the neural tube at first has a single layer of cells. They multiply and form three layers- ependymal, mantle and marginal layer

Neural tube closure begins at cephalic end

The mantle layer divides into a

Ventral part, the basal lamina and
Dorsal part, the alar lamina, separated by a groove, the sulcus limitans

Alar plate gives rise to sensory areas of the spinal cord and the sensory nuclei

Basal plate forms the motor areas of the spinal cord and motor nuclei

The cerebellum and its nuclei develop from the dorsal parts of the alar plate

Inferior olivary and Substantia nigra are sensory nuclei and thus derived from the alar plate

Hypoglossal is a motor nuclei and develops from the basal plate

Neuroepithelial Layer	Mantle Layer	Marginal Layer
These cells extend over the entire thickness of the wall and form a thick PSEUDOSTRATIFIED EPITHELIUM	Once the neural tube closes, neuroepithelial cells begin to give rise to another cell type.	The outermost layer of the spinal cord, the marginal layer, contains nerve fibers emerging from neuroblasts in the mantle layer.
Junctional complexes at the lumen connect them	These cells are characterized by a large round nucleus with pale nucleoplasm and a dark- staining nucleolus. These are primitive nerve cells, or NEUROBLASTS.	As a result of myelination of nerve fibers, this layer takes on a white appearance and therefore is called the white matter of the spinal cord.
After closure of neural tube, they divide rapidly, producing more and more neuroepithelial cells	They form the mantle layer, a zone around the neuroepithelial layer. The mantle layer later forms the gray matter of the spinal cord.

Forebrain
(Prosencephalon)	Telencephalon	Cerebral hemispheres
(Prosencephalon)	Diencephalon	Thalamus Hypothalamus Posterior Pituitary Pineal body
Midbrain
(Mesencephalon)	No division	Tectum
Hindbrain
(Rhombencephalon)	Metancephalon Cerebellum	Pons
	Myelencephalon	Medulla
Remainder of neural tube	No division	Spinal cord

3rd ventricle develops from diencephalon

4th ventricle develops from rhombencephalon

Myelin is formed in the central nervous system by oligodendrocytes
There are no myelinated fibers in the CNS before the end of the fifth fetal month
There is no myelination of the forebrain until the seventh fetal month. Most myelination in the telencephalon occurs in the third trimester and postnatally
The first neurones to acquire myelin sheaths are the olfactory, optic and acoustic cortical areas and the motor cortex (pyramidal cells)
The last to be myelinated are the projection commissure and association neurons of the cerebral hemispheres
Myelination is a critical process for the development of the brain because it enhances the speed of neural communication. It occurs most rapidly during the first 2 years of life, but continues until early adulthood

A single oligodendrocyte myelinates as many as 20 or 30 different CNS axonal segments, each over a length of 1 mm or less

Oligodendrocyte membrane extensions wrap around the axons in a concentric fashion to form the myelin sheath. Myelin proteins include proteolipid protein, myelin basic protein, myelin-associated glycoprotein, and a number of less abundant proteins detectable by electrophoretic separation

Active myelin synthesis starts in utero and continues for the first 2 years of life; slower synthesis continues during childhood and adolescence.

Lobe of Azygos Vein: This lobe appears especially in the right lung in approximately 1% of people. It develops when the apical bronchus grows superiorly, medial to the arch of the azygos vein and produces a linear marking on a radiograph of the lungs
Sequestration of lung: Lung tissue getting trapped in the core of a lobe is called as intralobar sequestration. Lung tissue completely separated from tracheobronchial tree replacing complete lobe is lobar sequestration
Potters Syndrome: It is pulmonary Hypoplasia with renal agenesis.

Thyroglossal Duct Cysts and Sinus: Normally, the thyroglossal duct atrophies and disappears, but a remnant of it may persist and form a cyst in the tongue or in the anterior part of the neck, usually just inferior to the hyoid bone.
Most thyroglossal duct cysts are observed by the age of 5 years. The swelling produced by a thyroglossal duct cyst usually develops as a painless, progressively enlarging, movable mass. The cyst may contain some thyroid tissue.
After infection of a cyst, a perforation of the skin occurs, forming a thyroglossal duct sinus that usually opens in the median plane of the neck, anterior to the laryngeal cartilages.
Ectopic Thyroid Gland: An ectopic thyroid gland is usually located along the course of the thyroglossal duct. Lingual thyroid tissue is the most common of ectopic thyroid tissues. Other sites:
- Larynx
- Trachea
- Esophagus
- Pericardium
- Pleura
- Ovaries

Struma Ovary:

It is a rare ovarian tumor defined by the presence of thyroid tissue
Most commonly, they occur as part of a teratoma, but may occasionally be encountered with serous or mucinous cystadenomas
Benign strumosis is a rare version of mature thyroid tissue implants throughout the peritoneal cavity

A 10-year-old girl with round 1 cm mass in midline of neck moving with movement of tongue	Throglossal duct cyst
A 15-year-old girl with round 1 cm on side of neck beneath and in front of sternocleidomastoid.	Branchial cyst
A 6-year-old with fluid filled translucent mass in supraclavicular area	Cystic hygroma

Ankyloglossia: The lingual frenulum normally connects the inferior surface of the tongue to the floor of the mouth. Sometimes the frenulum is short and extends to the tip of the tongue. This interferes with its free protrusion and may make breastfeeding difficult. A short frenulum usually stretches with time, making surgical correction of the anomaly unnecessary.

Macroglossia: An excessively large tongue is not common. Amyloidosis is associated with Macroglossia

Microglossia: An abnormally small tongue is extremely rare and is usually associated with micrognathia (underdeveloped mandible and recession of the chin) and limb defects (Hanhart’s syndrome)
Bifid Tongue
Fissured tongue

Laryngeal Atresia: This anomaly results from failure of recanalization of the larynx, which causes obstruction of the upper fetal airway. Distal to the region of atresia (blockage) or stenosis (narrowing), the airways become dilated, the lungs are enlarged and echogenic
Laryngeal web: Results from incomplete recanalization of the larynx during the 10th week. A membranous web forms at the level of the vocal folds, partially obstructing the airway
Laryngoptosis: Larynx is situated lower down in neck
Laryngeocele: Excessive enlargement of saccule of larynx.

Tracheoesophageal Fistula:
- A fistula between the trachea and esophagus
- Most affected infants are males
- In more than 85% of cases, the tracheoesophageal fistula (TEF) is associated with esophageal atresia
- A TEF results from incomplete division of the cranial part of the foregut into respiratory and esophageal parts during the fourth week
- Incomplete fusion of the tracheoesophageal folds results in a defective tracheoesophageal septum and a TEF between the trachea and esophagus

Polyhydramnios is often associated with esophageal atresia. The excess amniotic fluid develops because fluid cannot pass to the stomach and intestines for absorption and subsequent transfer through the placenta to the mother’s blood

Ectopia cordis: Non union of sternal plates exposing the heart to surface
Dextrocardia: If the heart tube bends to the left instead of to the right, the heart is displaced to the right and there is transposition — the heart and its vessels are reversed left to right as in a mirror image. Dextrocardia is the most frequent positional abnormality of the heart. In isolated dextrocardia, the abnormal position of the heart is not accompanied by displacement of other viscera
Maybe associated with

Situs Inversus/ Kartageners Syndrome/Immotile Cilia Syndrome

Atrial Septal Defects: An atrial septal defect (ASD) is a common congenital heart anomaly and occurs more frequently in females than in males. The most common form of ASD is patent oval foramen. A small isolated patent oval foramen is of no hemodynamic significance; however, if there are other defects (e.g. pulmonary stenosis or atresia), blood is shunted through the oval foramen into the left atrium and produces cyanosis.
Ventricular Septal Defects: VSDs are the most common type of CHD, accounting for approximately 25% of defects. VSDs occur more frequently in males than in females. VSDs may occur in any part of the IV septum but membranous VSD is the most common type frequently, small VSDs close spontaneously. Most people with a large VSD have massive left-to-right shunting of blood. Muscular VSD is a less common type of defect and may appear anywhere in the muscular part of the interventricular septum. Sometimes there are multiple small defects, producing what is sometimes called the ‘Swiss cheese’ VSD.
Cor biloculare: Two chambered heart
Cor Triloculare: Three chambered heart
L. Cor triloculare biatriatum: (Two atria, one ventricle): Absence of the IV septum-single ventricle or common ventricle-resulting from failure of the IV septum to form is extremely rare and results in a three-chambered heart (L. cor triloculare biatriatum).
Transposition of the Great Arteries: TGA is the most common cause of cyanotic heart disease in newborn infants. TGA is often associated with other cardiac anomalies (e.g. ASD and VSD).

In typical cases, the aorta lies anterior and to the right of the pulmonary trunk and arises from the morphologic right ventricle, whereas the pulmonary trunk arises from the morphologic left ventricle. The aorticopulmonary septum fails to pursue a spiral course during partitioning of the bulbus cordis and TA

This defect is thought to result from failure of the conus arteriosus to develop normally during incorporation of the bulbus cordis into the ventricles

Recent studies suggest that defective migration of neural crest cells may also be involved.

Tetralogy of Fallot: This classic group of four cardiac defects
- Pulmonary stenosis (Obstruction of right ventricular outflow)
- VSD
- Dextroposition of aorta (Overriding or straddling aorta)
- Right ventricular hypertrophy
Coarctation of the Aorta: Aortic coarctation (constriction) occurs in approximately 10% of children and an adult with CHDs. Coarctation is characterized by an aortic constriction of varying length. Most coarctations occur distal to the origin of the left subclavian artery at the entrance of the DA (juxtaductal coarctation). The classification into preductal and postductal coarctations is commonly used. Coarctation of the aorta occurs twice as often in males as in females and is associated with a bicuspid aortic valve in 70% of cases.

Cystic hygroma: Large swellings usually appear in the inferolateral part of the neck and consist of large single or multilocular, fluid-filled cavities. Hygromas maybe present at birth, but they often enlarge and become evident during infancy. Most hygromas appear to be derived from abnormal transformation of the jugular lymph sacs
- Represents lymphatic venous anastamotic failure
- Located usually in the neck at lower in posterior triangle
- Brilliantly translucent

Esophageal Atresia: Esophageal atresia is associated with tracheoesophageal fistula in more than 85% of cases. Atresia may occur as a separate anomaly, but this is less common. Esophageal atresia results from deviation of the tracheoesophageal septum in a posterior direction as a result there is incomplete separation of the esophagus from the laryngotracheal tube. A fetus with esophageal atresia is unable to swallow amniotic fluid; consequently, this fluid cannot pass to the intestine for absorption and transfer through the placenta to the maternal blood for disposal. This results in polyhydramnios

Esophageal Stenosis: Narrowing of the lumen of the esophagus can be anywhere along the esophagus, but it usually occurs in its distal third, either as a web or as a long segment of esophagus with a thread like lumen. Stenosis usually results from incomplete recanalization of the esophagus.
Short Esophagus (Congenital Hiatal Hernia): Initially the esophagus is very short. Its failure to elongate sufficiently as the neck and thorax develop results in displacement of part of the stomach superiorly through the esophageal hiatus into the thorax-congenital hiatal hernia. Most hiatal hernias occur long after birth, usually in middle-aged people.
20Dysphagia Lusoria: Abberant vessels compressing esophagus leading to dysphagia. Usually Abnormal right subclavian artery is implicated.
Duodenal Atresia: Complete occlusion of the lumen of the duodenum. If recanalization of the lumen fails to occur a short segment of the duodenum is occluded. The blockage occurs nearly always at the junction of the bile and pancreatic ducts (hepatopancreatic ampulla) but occasionally involves the horizontal (third) part of the duodenum.
In infants with duodenal atresia, vomiting begins a few hours after birth. The vomitus almost always contains bile; duodenal atresia may occur as an isolated anomaly, but other congenital anomalies are often associated with it, e.g. anular pancreas cardiovascular abnormalities, anorectal anomalies, and malrotation. Importantly, approximately one third of affected infants have Down syndrome and an additional 20% are premature. Duodenal atresia is associated with bilious emesis (vomiting of bile) because the blockage occurs distal to the opening of the bile duct. Polyhydramnios also occurs because duodenal atresia prevents normal intestinal absorption of swallowed amniotic fluid. The diagnosis of duodenal atresia is suggested by the presence of a ‘double bubble‘ sign on plain radiographs or ultrasound scans. This appearance is caused by a distended, gas-filled stomach and proximal duodenum.
Riedels Lobe: A tongue like extension of right lobe of liver.
Phrygian cap: Fundus of the gallbladder folded upon itself giving rise to an appearance of cap worn by people of an ancient Asian community of Phrygia.
Moynihans Hump: Normally the arterial supply of gallbladder is from cystic artery which is a branch of Right hepatic artery. Sometimes an accessory cystic artery is also seen to arise from either Gastroduodenal or right hepatic artery

The Right hepatic artery takes a tortuous course called ‘caterpillar turn’ or ‘Moynihans hump.’ This can be a source of profuse bleeding.

Intrahepatic gallbladder is one of the ectopic locations of the gallbladder. The gallbladder is usually intrahepatic during its embryologic period and becomes extrahepatic later on in its development. In adults approximately 60% of intrahepatic gallbladders are associated with gallstones
Double and Triple gallbladders have been reported, the latter being extremely rare. Double gallbladders may share a common cystic duct and be completely separated, or they maybe divided by a septum. When they do not share a common outlet, the cystic ducts of double or triple gallbladders open separately into the common bile duct or, less commonly, into the right hepatic duct
Choledochal Cyst: Choledochal cysts are congenital cystic dilatations of the extrahepatic and/or intrahepatic biliary tree. They are rare. Originally, they were described as cystic dilatations of the extrahepatic duct system. Subsequently this classification was extended to include the frequent association with cystic dilatation of the duct system within the liver, a condition described in 1958 and now known as Caroli’s disease.
Extrahepatic Biliary Atresia: This is the most serious anomaly of the extrahepatic biliary system and occurs in one in 10,000 to 15,000 live births
The most common form of extrahepatic biliary atresia is obliteration of the bile ducts at or superior to the porta hepatis
Biliary atresia could result from a failure of the remodeling process at the hepatic hilum or from infections or immunologic reactions during late fetal development
Jaundice occurs soon after birth and stools are acholic (clay colored).
Accessory Pancreatic Tissue: Accessory pancreatic tissue is most often located in
- The wall of the stomach
- Wall of duodenum
- In an ileal diverticulum a/Meckel diverticulum
Anular Pancreas:
- May cause duodenal obstruction
- The ring like or anular part of the pancreas consists of a thin, flat band of pancreatic tissue surrounding the descending or second part of the duodenum.
- An anular pancreas may cause obstruction of the duodenum either shortly after birth or later. Infants present with symptoms of complete or partial bowel obstruction. An anular pancreas maybe associated with
- Down syndrome
- Intestinal atresia
- Imperforate anus
- Pancreatitis
- Malrotation
21Congenital Omphalocele: This anomaly is a persistence of the herniation of abdominal contents into the proximal part of the umbilical cord. Herniation of intestines and herniation of liver and intestines occurs
Infants with these large omphaloceles often suffer from pulmonary and thoracic hypoplasia and a delayed closure is a better clinical decision. The covering of the omphalocele is by amnion and peritoneum.
Umbilical Hernia: When the intestines return to the abdominal cavity during the 10th week and then herniate through an imperfectly closed umbilicus, an umbilical hernia forms. This common type of hernia is different from an omphalocele. In an umbilical hernia, the protruding mass (usually the greater omentum and part of the small intestine) is covered by subcutaneous tissue and skin. The defect through which the hernia occurs is in the linea alba. The hernia protrudes during crying, straining, or coughing and can be easily reduced through the fibrous ring at the umbilicus. Surgery is not usually performed unless the hernia persists to the age of 3 to 5 years.
Gastroschisis: This anomaly is a relatively uncommon congenital abdominal wall defect. Gastroschisis results from a defect lateral to the median plane of the anterior abdominal wall. The linear defect permits extrusion of the abdominal viscera without involving the umbilical cord. The viscera protrude into the amniotic cavity and are bathed by amniotic fluid.

Nonrotation occurs when the intestine does not rotate as it re-enters the abdomen. As a result, the caudal limb of the midgut loop returns to the abdomen first and the small intestines lie on the right side of the abdomen and the entire large intestine is on the left and the cecum lies just inferior to the pylorus of the stomach. The cecum is fixed to the posterolateral abdominal wall by peritoneal bands that pass over the duodenum. These bands and the volvulus (twisting) of the intestines cause duodenal obstruction. When midgut volvulus occurs, the superior mesenteric artery maybe obstructed, resulting in infarction and gangrene of the intestine supplied by it. Infants with intestinal malrotation are prone to volvulus and present with bilious emesis.
Reversed Rotation: In very unusual cases, the midgut loop rotates in a clockwise rather than a counterclockwise direction. As a result, the duodenum lies anterior to the superior mesenteric artery rather than posterior to it, and the transverse colon lies posterior instead of anterior to it. In these infants, the transverse colon maybe obstructed by pressure from the superior mesenteric artery.

Congenital Megacolon or Hirschsprung Disease:

Infants with congenital megacolon or Hirschsprung’s disease lack autonomic ganglion cells in the myenteric plexus distal to the dilated segment of colon

(Hirschsprung’s disease is the congenital absence of enteric neurons in the submucosal and myenteric plexuses, due to an arrest of the embryonic caudal migration of the enteric neurons along the gut. The aganglionic segment remains contracted, dilating the proximal normal bowel

The severity of symptoms and the age at diagnosis are related to the length of the aganglionic segment. Involvement of the rectum or additional parts of the colon results in constipation or obstipation in infancy, requiring emergent resection of the a ganglionic bowel and a pull-through anastomosis to the anus.)
22Imperforate Anus and Anorectal Anomalies: Imperforate anus occurs approximately once in every 5000 newborn infants and is more common in males. Most anorectal anomalies result from abnormal development of the urorectal septum, resulting in incomplete separation of the cloaca into urogenital and anorectal portions. There is normally a temporary communication between the rectum and anal canal dorsally from the bladder and urethra ventrally but it closes when the urorectal septum fuses with the cloacal membrane.
Anal Agenesis, with or without a Fistula: The anal canal may end blindly or there maybe an ectopic anus or an anoperineal fistula that opens into the perineum. The abnormal canal may, however, open into the vagina in females or the urethra in males.
Anal Stenosis: The anus is in the normal position, but the anus and anal canal are narrow. This anomaly is probably caused by a slight dorsal deviation of the urorectal septum as it grows caudally to fuse with the cloacal membrane. As a result, the anal canal and anal membrane are small.

USMLE Case Scenario

Embryologically, The Gut rotates and the rotation occurs in a way that:

The large intestine rotates in a clockwise manner around the axis of the celiac trunk
The large intestine rotates in a clockwise manner around the axis of the superior mesenteric artery
The large intestine rotates in a clockwise manner around the axis of the inferior mesenteric artery
The large intestine rotates in a counterclockwise manner around the axis of the celiac trunk
The large intestine rotates in a counterclockwise manner around the axis of the superior mesenteric artery
The large intestine rotates in a counterclockwise manner around the axis of the inferior mesenteric artery

Ans. 5. The large intestine rotates in a counterclockwise manner around the axis of the superior mesenteric artery

Horseshoe Kidney: In 0. 2% of the populations, the poles of the kidneys are fused; usually the inferior poles fuse. The large U-shaped kidney usually lies in the hypogastrium, anterior to the inferior lumbar vertebrae. Normal Persons with Turner’s syndrome have horseshoe kidneys.
Ectopic Ureter: An ectopic ureter does not enter the urinary bladder. In males, ectopic ureters usually open into the neck of the bladder or into the prostatic part of the urethra, but they may enter the ductus deferens, prostatic utricle, or seminal gland. In females, ectopic ureters may open into the
- Bladder neck
- Urethra
- Vagina
- Vestibule of the vagina
23An ectopic ureter: Results when the ureter is not incorporated into the trigone in the posterior part of the urinary bladder. Instead it is carried caudally with the mesonephric duct and is incorporated into the middle pelvic portion of the vesical part of the urogenital sinus.

Cystic Kidney Diseases

In autosomal recessive polycystic kidney disease, diagnosed at birth or in utero by ultrasonography, both kidneys contain many hundreds of small cysts which result in renal insufficiency.
Multicystic dysplastic kidney disease results from dysmorphology during development of the renal system. The outcome for children with multicystic dysplastic kidney disease is generally good because the disease is unilateral in 75% of the cases. In multicystic dysplastic kidney disease, fewer cysts are seen than in autosomal recessive polycystic kidney disease and they range in size from a few millimeters to many centimeters in the same kidney.
Congenital Adrenal Hyperplasia (CAH): An abnormal increase in the cells of the suprarenal cortex results in excessive androgen production during the fetal period. In females, this usually causes masculinization of the external genitalia. Affected male infants have normal external genitalia, and the syndrome may go undetected in early infancy. Later in childhood in both sexes, androgen excess leads to rapid growth and accelerated skeletal maturation. CAH is a group of autosomal recessive disorders that result in virilization of female fetuses.

Mesonephric Duct Remnants in Males

The cranial end of the mesonephric duct may persist as an appendix of the epididymis, which is usually attached to the head of the epididymis Caudal to the efferent ductules, some mesonephric tubules may persist as a small body, the paradidymis. It forms
- Epididymis
- Ductus deferens
- Seminal vesicles
- Ejaculatory ducts
- Appendix epididymis
Mesonephric Duct Remnants in Females

The cranial end of the mesonephric duct may persist as an appendix vesiculosa. A few blind tubules and a duct, the epoophoron, correspond to the efferent ductules and duct of the epididymis in the male. The epoophoron may persist in the mesovarium between the ovary and uterine tube. Closer to the uterus, some rudimentary tubules may persist as the paroophoron. Parts of the mesonephric duct, corresponding to the ductus deferens and ejaculatory duct, may persist as Gartner’s duct cysts between the layers of the broad ligament along the lateral wall of the uterus and in the wall of the vagina.
Paramesonephric Duct Remnants in Males

The cranial end of the paramesonephric duct may persist as a vesicular appendix of the testis, which is attached to the superior pole of the testis

The prostatic utricle, a small saclike structure that opens into the prostatic urethra, is homologous to the vagina.
Paramesonephric Duct Remnants in Females
Part of the cranial end of the paramesonephric duct that does not contribute to the infundibulum of the uterine tube may persist as a vesicular appendage it forms
- Uterus
- Cervix
- Uterine tubes
- Hydatid of morgagni

24Cryptorchidism or Undescended Testes
- The term cryptorchidism (Greek cryptos = hidden, orchis = testis) should be reserved for impalpable, usually abdominal, testes
- There is a higher incidence of undescended testes in premature than in full-term babies
- Two-thirds of undescended testes in newborn infants will descend, usually by 6 weeks in term and 3 months in preterm babies
- There is an increased incidence of cryptorchidism in anencephalics and other cerebral anomalies.
Ectopic Testes: After traversing the inguinal canal, the testis may deviate from its usual path of descent and lodge in various abnormal locations
- Interstitial (external to aponeurosis of external oblique muscle)
- In the proximal part of the medial thigh
- Dorsal to the Penis
- On the opposite side (crossed ectopia)
- Exstrophy of the bladder results from a rare ventral body wall defect through which the posterior wall of the urinary bladder protrudes onto the abdominal wall. Epispadias is a common associated anomaly in males; the urethra opens on the dorsum of the penis.

Spina Bifida: The original defect lies in the vertebrae when their laminae fail to cover the spinal cord dorsally. Spina bifida maybe simple or complicated. Complicated Spina bifida is associated with involvement of the cord and its membranes
Rarely do the two halves of the vertebral body fail to fuse and the spinal cord protrudes anteriorly through the gap. This rarity is called as anterior spina bifida
Spina bifida occulta: Here the spinal cord is normal. The defect is not manifest externally and usually a tuft of hair is present on the skin over the affected area
Meningocele: The Arachnoid and the Piamater covering the spinal cord protrude through the opening of the bifid spine and form a cystic swelling
Meningomyelocele: Here the spinal cord along with its meninges and the spinal nerves are seen to protrude. It is a more serious condition owing to development of infection of the cord itself
This condition is associated with displacement of medulla and a part of cerebellum which cause obstruction of the foramen magnum producing hydrocephalus. An association of hydrocephalus and Meningomyelocele is called Arnold Chiari malformation
Syringomyelia: Once the central canal of the spinal cord is distended with excessive fluid it is called Syringomyelia
Myelomalacia: Abnormal softening of spinal cord. Usually seen after trauma to spinal cord

In Syringomyelia there is softening of the spinal cord and the central canal becomes very wide at lesion in this position will interrupt the pain and temperature fibers which pass in front of the central canal as they cross from one side to another
Syringomyelia usually occurs in the lower cervical and the upper thoracic regions of the spinal cord and the loss of pain and temperature
Only the fibers of the pain and temperature which pass in front of the central canal are injured: the lateral spinothalamic tracts ‘themselves’ remain normal and there is no loss of pain and temperature in the lower limbs
Touch can be felt in the area of the skin in which pain and temperature are lost: this condition in which pain and temperature is lost while touch is nearly normal called Dissociated sensory loss.

USMLE Case Scenario

Which of the following embryonic structures gives rise to the adrenal cortex?

Ectoderm
Endoderm
Mesoderm
Mesonephros

Ans. 3. Mesoderm

They have only one pole

Both Axon and Dendrons arise by a common stem.

Fetal life
Posterior root ganglion
Sensory nucleus of the fifth cranial nerve

They have two poles

Axon and Dendron lie at opposite poles

Cochlear ganglion of the eight nerves
Vestibular ganglion of the eight nerves
Retina
Olfactory nerve

They have multiple poles

The Axon and all other Dendrons form multiple poles

The spinal cord
Cerebral cortex
Cortex of cerebellum

Leptotene: Chromosomes become visible
Zygotene: Pairing of chromosomes
Pachytene: Tetrad formation, crossing over, chiasmata formation
Diplotene: Chromosomes break
Metaphase: Spindle formation
Anaphase: Chromosomes move from equator to poles
Telophase: Chromosomes move completely to opposite sides

Of the two X-chromosomes in a Female only one is functionally active. The other (Inactive) X-chromosome forms a mass of heterochromatin that lies just under the nuclear membrane. This mass of heterochromatin can be identified in suitable preparations and can be useful in determining whether a particular tissue belongs to a male or a female. Because of this association with sex this mass of heterochromatin is called the SEX CHROMATING. It is also called a BARR-BODY after the name of the scientist who first discovered it.

In NEURONS it forms a rounded mass lying very close to the nucleolus and is therefore called a NUCLEOLAR SATELLITE.
In NEUTROPHIL LEUCOCYTES it may appear as an isolated round mass attached to the rest of the nucleus by a narrow band, thus resembling the appearance of a DRUM-STICK. Rarely, some individuals may have more than two X-chromosomes. In these cases only one X-chromosome is active (and hence euchromatic) while others are represented by masses of heterochromatin.

In normal females XX	There is one barr body
In normal males XY	There is no barr body
In Turners Syndrome XO	There is no barr body
In males with Klienfilters syndrome XXY	There is one barr body
In super female XXX	There are two barr bodies
The number of Barr bodies is (X-1)

The number of chromosomes found in somatic cells is constant and is termed the diploid (2n) number. Each gamete, however, has only half the diploid number and is said to be haploid (n). In order to maintain this regularity, two types of cell division occur: mitosis, which is the cell division occurring in somatic tissues during growth and repair, and meiosis, which is the specialized form of cell division occurring when gametes form.

The function of mitosis is to distribute and maintain the continuity of the genetic material in every cell of the body. This process consists of a number of different phases, which results in an equal distribution of the chromosomes to the two daughter cells. The cell cycle has four stages: mitosis (M), gap1 (G1), synthesis (S), and gap2 (G2). The G1 phase follows mitosis, during which RNA and protein synthesis occurs. S is the period during which DNA replication takes place and the DNA content of the cell doubles, and G2 is the period during which energy requirements for cell division are built-up and any repair of errors in DNA synthesis takes place.

27Meiosis

This process occurs only during the formation of the gametes and results in four daughter cells, each with the haploid number of chromosomes. In males each primary spermatocyte forms four functional spermatids that develop into sperm, while in females each oocyte forms only one ovum, the remaining products of meiosis being nonfunctional polar bodies.

Lyonization

In females, the sex chromosomes are identical in size and are genetically homologous chromosomes (as in the case of autosomes); however, in the normal diploid interphase cell, one of the X’s forms a condensed heterochromatic body called the Barr body. These condensations, together with evidence from coat color pattern in mice, led Lyon to hypothesize X-inactivation.

She Stated

In each somatic cell there is inactivation of all but one of the X-chromosomes;
This process occurs early in development and is random with respect to maternally or paternally derived X-chromosomes in different cells; and
Once a particular X is inactive, it is inactive in all daughter cells.

The Skin has stratified squamous epithelium
Classically epidermis has four layers
Normal turn over of epidermis is 4 weeks
Skin doubling time is 4 weeks

Stratum Germinativium composed of stratum Basale and Stratum Spinosum
Stratum Granulosum (Granular cell layer)
Stratum Lucidum (Clear cell layer)
Stratum Corneum (horny cell layer)

Stratum Germinativium is also called as Malphigian layer composed of
1. Basal cell layer
2. Prickle cell layer (stratum spinosum)
The Basal cell layer is composed of single layer of columnar cells resting on a clear wavy basement membrane From the basal borders of these cells Cytoplasmic processes extend anchoring the epidermis to dermis Melanocytes are present here.
- Acantholytic cells are present here
- Dermatophytes are present here
- It is underdeveloped in VLBW infants

The prickle cell layer (stratum spinosum) consists of 4–6 layers of cells which are polygonal and connected together by tonofilaments giving them a prickly appearance.

Stratum Granulosum
- Consists of 3–4 layers of flattened cells rich in keratohyaline granules
- The keratohyaline granules eventually fill much of the cell, and it is these granules which give the cells of the stratum Granulosum its granular appearance
- The keratohyaline granules contain a protein called filaggrin, the function of which appears to be to bind the tonofibrils together, converting them into keratin
Stratum Lucidum
- Consists of few layers of dead, non nucleated cells without cell boundaries
- These cells are rich in Eleidin granules
Stratum Corneum
- It is the most superficial layer of epidermis
- It is made of flat, dead cornified cells which have horny scales
- They are continuously shed from the surface and replaced by newer cells

28The Dermis is formed of CT present beneath the epidermis. It is made of two layers continuous with each other
The Papillary layer or the loose connective tissue layer
The Reticular layer or the deeper layer

The Hypodermis is continuous with the dermis. It is formed of loose CT rich in blood vessels, loose CT, nerve endings.

Are located primarily in the stratum spinosum
They function in the immune system as antigen presenting cells
They stain selectively with gold chloride and contain numerous rod like or racket-shaped Cytoplasmic granules (Birbeck’s granules)

Are located in the stratum basale
They contain granules which contain catecholamines
The base of a Merkel cell makes contact with the expanded terminal disk of a nerve fiber, forming a special receptor which functions as a mechanoreceptor (detection of touch)

Are found throughout the epidermis
They are antigen presenting cells

Alveoli of lungs
Mesothelium of pleura, peritoneum and pericardium
Endothelium of heart and blood vessels

Lining of the thyroid follicles
Germinal epithelium of ovary
Anterior surface of lens of eye

The lining of stomach
Intestines
Gallbladder

Fallopian tubes and the uterus
Central canal of spinal cord
Osseous part of eustachian tube

It is a simple type of columnar cells resting on a clear wavy basement membrane. The cells are crowded over each other and appear multilayered. The nuclei are arranged at different levels, some situated basal and others centrally as a result of which a false impression of multilayered cells is created. However, most of the cells reach the basement membrane. The cells maybe ciliated or nonciliated

With cilia

Nasal cavity, nasal air sinuses, nasopharynx, larynx, trachea and bronchi
Eustachian tube in its cartilaginous parts

Without cilia

Vas deferens
Part of male urethra

The surface of the cells maybe keratinized (Protective function) as in case of

Epidermis of skin
External ear
External nose

The surface of the cells maybe without keratin called Nonkeratinized as in case of

Esophagus
Tongue
True vocal cords
Cornea
Tonsil

Conjunctival fornicies
Penile part of male urethra
Anorectal junction

It is a type of epithelium composed of multiple cell layers
They have extra reserve of cell membrane
The top cell layers are broader
The intermediate cell layers are polyhedral without intercellular bridges separated by mucus like substance. The cells can undergo transition in relaxed and contracted state. In the relaxed state the number of layers is 6–8 while as in the contracted state it is 2–3 layers
The basal cell layers are cuboidal.

Calyces
Ureter
Urinary bladder
UV junction
Male urethra

Gland	Duct	Type of Gland	Duct opening
Parotid	Stensens duct	Serous	Vestibule of mouth opposite second upper molar
Submandi-bular	Whartons duct	Mixed but predominantly serous	On the floor of mouth on summit of sublingual papilla at the side of frenulum of tongue
Sublingual	Bartholins duct	Mixed but predominantly mucus	On the floor of mouth on summit of sublingual papilla

External carotid artery
Retromandibular vein
Facial nerve

Classic Hepatic Lobule: This model is based on the direction of blood flow. In sections, liver substructure exhibits a pattern of interlocking hexagons; each of these is a classic lobule. Whereas lobules in pigs are defined by a sheath of connective tissue, there is less connective tissue in humans and the lobule boundaries are indistinct. The central vein at its center and the alternating hepatocyte plates and sinusoids that lie between them.
Portal Canal/triad: One triad occupies a potential space (portal space) at each of the 6 corners of the lobule. Each triad contains 3 main elements surrounded by connective tissue: a portal venule (a branch of the portal vein), a hepatic arteriole (a branch of the hepatic artery) and a bile ductule (a tributary of the larger bile ducts). A lymphatic vessel may also be seen. In the portal canal blood vessels and bile ductules are separated by a space called as Space of Mall
Portallobule: This model is based mainly on the direction of bile flow, which is opposite to that of blood. From this perspective, the liver parenchyma is divided into interlocking triangles, each of which has a portal triad at the center and a central vein at each of its 3 comers
Hepatic lobule: It is the structural unit of liver. It has a central vein. A single vein marks the center of each lobule. This vessel is easily distinguished from those in the portal triad by its larger opening and lack of a connective tissue investment.
- Kuffercells are Reticuloendothelial cells of liver
- Itto cells are fat storing cells in liver
- 'Space of Dissie’ and ‘Space of Mall’ are seen in Liver

Hassals corpuscles	Thymus
Corpora amaylacea	Prostate
Corpora atretica	Ovary
Germinal center	Lymph node
Corpora aranacea	Pineal gland
Herring bodies	Pituitary gland
Cords of Billiroth	Spleen

The Mucus neck cells

Called so as they are present in the necks of glands
They secrete mucin which serves as a protective layer against HCL
31They appear pale because of dissolved mucin
They are low columnar with basal flat nuclei

The Chief cells (The Peptic cells or the Zymogen cells)

Called as chief because they line the main part of the body of the gland
They are low columnar with basal round nuclei
They secrete pepsinogen

Oxyntic Cells (Parietal Cells)

They are scattered in between peptic cells
They are highly acidophilic
Intrinsic factor of Castle is secreted by parietal cells
They secrete HCL
They contain secretory canaliculi and are rounded

The Argentaffin Cells

They are chromaffin positive and stain positive with Silver salts
They also contain acidophilic granules and are oval in shape

Simple Columnar Cells

Line the villi and crypts
Have free brush border due to presence of microvilli to increase surface area

Goblet Cells

Are also present in the villi and crypts
They are unicellular glands
They are flask shaped
They secrete mucin

Paneth Cells

Are acidophilic
Secrete intestinal enzymes
Rich in Rough ER

Argentaffin cells

These are cells with silver staining properties
They secrete serotonin

The diffuse lymphatic tissue is a collection of lymphatic tissue in:

Alimentary tract
Respiratory tract
Genitourinary tract

The lymphoid tissue is deposited randomly in the subepithelial layers and placed strategically so as to detect and destroy the pathogenic agents instantaneously and effectively. Located in adventitia

Functioning in close collaboration is other set of localized concretions of lymphocytes in the form of follicles and nodules such as:

Pharyngeal tonsils
Palatine tonsils
Lingual tonsils
Peyers patches in the small intestine especially in the ileum
Lymphoid follicles in appendix/abdominal tonsil

32In the alimentary canal the diffuse and the local lymphatic systems combine synergistically to form the GUT ASSOCIATED LYMPHOID TISSUE (GALT). The main function of this system is to act along with the main lymphatic organs.

Eponyms	Description
Bowman’s capsule	Glomerular capsule of the kidney seen on histology slides
Bowman’s membrane	Layer in the cornea below epithelium seen on histology slides
Brunner’s glands	Glands in the duodenum seen on histology slides
Bundle of His	Atrioventricular bundle
Cords of Billroth	Splenic cords of the spleen seen on histology slides
Crypts of Lieberkuhn	Epithelial glands in the small intestine seen on histology slides
Descemet’s membrane	Limiting layer of the cornea seen on histology slides
Ducts of Bellini	Papillary duct of the kidney seen on histology slides
Ducts of Luschka	Small ducts found in the connective tissue between the gallbladder and the liver
Golgi aparatus	Intracellular organelle
Golgi tendon organ	Sensory nerve ending embedded in a tendon for proprioception
Graafian follicle	Tertiary follicle of an ovary seen on a histology slide
Haversian canal	Central canal of an osteon of bone seen on a histology slide
Haversian system	Osteon of bone seen on a histology slide
Islets of Langerhans	Pancreatic islets of the pancreas seen on histology slides
Leydig cells	Interstitial cells of the testis
Loop of Henle	U shaped loop in the nephron of the kidney
Krause end bulbs	Cylindrical/oval sensory receptor
Malpighian corpuscle	Renal corpuscle of the kidney seen on histology slides
Meissner’s corpuscle	Mechanoreceptor
Meissner ‘s plexus	Submucosal plexus
Merkel’s disk	Tactile receptor
Moll’s gland	Glands of the conjunctiva
Nissl bodies	Rough endoplasmic reticulum of a neuron
Node of Ranvier	Area between two Schwann cells covering nerve fibers with axon which is not covered by myelin
Organ of Corti	Small organ of sound transduction; spiral organ
Pacinian corpuscle	Lamellar corpuscle
Peyer’s patches	Aggregates of lymphatic tissue in the ileum seen on histology slides
Purkinje fibers	Part of the conducting system of the heart
Renal columns of Bertin	Renal columns seen on histology slides
Ruffini’s corpuscle	Sensory receptor
Space of Disse	Perisinosoidal space of the liver seen on histology slides
Volkmann’s canals	Perforating canals of bone
Wharton’s jelly	Mucous connective tissue seen in umbilical cord

C5 and C6 roots join to form the upper trunk
C7 root alone forms the middle trunk
C8 and T1 roots join to form the lower trunk

Each trunk divides into an anterior and posterior division:

All the posterior divisions join to form the posterior cord
The upper two anterior divisions join to form the lateral cord
The lowest anterior division alone forms the medial cord

Branches from the roots

Nerve to serratus anterior (C5, C6, C7)
Dorsal scapular nerve (C5)
Muscular branches to the 3 scalene muscles

Branches from the trunks

Suprascapular nerve (C5, C6)
Subclavius nerve (C5, C6)

Branches from the cords

Medial cord

Medial head of median nerve (C8, T1)
Medial pectoral (C8, T1)
Ulnar nerve (C8, T1)
Median cutaneous nerve of forearm (C8, T1)
Medial cutaneous nerve of arm (T1)

Lateral cord

Lateral pectoral (C5, C6, C7)
Lateral head of median (C5, C6, C7)
Musculocutaneous (C5, C6, C7)

Posterior cord

Radial (C5, C6, C7, C8, T1)
Axillary (C5, C6)
Nerve to latissimus dorsi (C6, C7, C8)
Subscapular Upper (C5, C6)
Subscapular lower

Upper trunk deformity is called

Erbs palsy or policemans
Waiters tip
Porter tip deformity

Lower trunk deformity is called Klumpkes palsy

Ulnar nerve supplies medial 1/3 of palm. (Hypothenar area)
Ulnar nerve in hand supplies:
- 3, 4 Lumbricals
- Palmar and dorsal interosei
- Adductor pollicis
- Hypothenar muscles
Ulnar nerve in hand supplies flexor carpi ulnaris and medial half of flexor digitorum profundus

Lesion of ulnar nerve causes:
- Weakness of ulnar deviation
- Weakness of wrist flexion
- Adductor pollicis paralysis with loss of thumb adduction

Positive card test
Positive book test/Froment sign
Positive Egawas test
Ulnar claw hand

Does not supply arm
Supplies all flexors except flexor carpi ulnaris and medial half of flexor digitorum profundus in forearm
Supplies thenar eminence
- Lumbrical 1 and 2
- Opponens pollicis
- Abductor pollicis brevis
- Flexor pollicis brevis in hand. (LOAF)

Implicated in:

Lunate dislocation

Ape thumb deformity
Carpal tunnel syndrome
Pointing index
Pen test is positive in median nerve injury
Loss of opposition and abduction of thumb

Affects the median nerve. Patients often note a tingling, a loss of sensation, or diminished sensation in the digits. There is also often a loss of coordination and strength in the thumb, because the median nerve also sends fibers to the abductor pollicis brevis, flexor pollicis brevis, and the opponens pollicis. A final function of the median nerve distal to the carpal tunnel is control of the first and second lumbricals which function to flex digits two and three at the metacarpophalangeal joints and extend interphalangeal joints of the same digits.

Supplies:

Extensor compartment of arm, forearm
Triceps
Anconeus and extensors of forearm. Extension of MCP joint
Injury to RN Causes
- Wrist drop
- Saturday night palsy/crutch palsy
Commonly injured in Radial groove

USMLE Case Scenario

A 43-year-old man suffered an injury in his left upper limb. His radial nerve was injured. The radial nerve is at greatest risk for injury with:

Fracture of the surgical neck of the humerus
Fracture of the shaft of the humerus
Supracondylar fracture of the humerus
Olecranon fractures

Ans. 2. Fracture of the shaft of the humerus

In ‘supracondylar fracture’ of humerus triangular relationship of three bony prominences is not disturbed. In elbow dislocation it is disturbed
The ‘shoulder joint’ is the most commonly dislocated major joint in the body
MC dislocation is inferior
In subacromial bursitis, person feels pain when arm is abducted. ‘Dawbarns sign’ is seen in subacromial bursitis
PIN (Posterior interosseous nerve) is a branch of radial nerve. No wrist drop is seen in injury to PIN
If posterior medial aspect of elbow is banged against a hard object, it mat cause temporary ulnar nerve damage. This may result in painful tingling sensations along ulnar aspect of forearm and hand. Because of these sensations, this area of elbow is called ‘Funny bone/Crazy bone’
Eye of hand: median nerve. Enables the individual to feelthinness and texture of cloth
Pronator syndrome: compression of Median nerve between two heads of pronator teres
Infection of pulp spaces is Felon/Whitlow

Important Nerves Involved in
Wrist drop Foot drop Meralgia parasthetica Winging of scapula Erbs Palsy Klumpkes palsy Sluders neuralgia	Radial nerve palsy Common peroneal nerve palsy Lateral cutaneous nerve of thigh Long thoracic nerve of bell Upper trunk of brachial plexus Lower trunk of brachial plexus Middle turbinate pressing anterior ethmoidal nerve

The Axillary nerve is a branch of the posterior cord of the brachial plexus

It is particularly susceptible to the injury in shoulder dislocations that displace the humeral head or in fracture of the surgical neck of the humerus

A poorly placed crutch (Crutch Palsy) may also damage this nerve causing paralysis of the Teres minor and Deltoid muscles

Arm abduction is impaired and there is associated loss of sensation over the lower half of the deltoid
When the head of the humerus dislocates from the glenohumeral joint, it exits inferiorly, where the joint capsule is the weakest. Immediately inferior to the glenohumeral joint, the axillary nerve exits from the axilla by passing through the quadrangular space. At this location, the downward movement of the head of the humerus can stretch the axillary nerve. The axillary nerve innervates the deltoid muscle after leaving the axilla.
The Lower Subscapular nerve innervates the Teres major, which is responsible for adducting and medially rotating the arm, it is a branch of the posterior chord (C5 C6) of the brachial plexus.
The Suprascapular nerve innervates the Supraspinatus and Infraspinatus muscle that are responsible for abduction and lateral rotation of the arm. The nerve is derivated from the C5 and C6 nerve roots

In shoulder abduction:

Humerus elevates

Clavicle rotates

Lateral rotation of scapula occurs along with acromioclavicular joint movement.

The Throacodorsal nerve innervates the latissimus dorsi muscle that is responsible from adduction and extension of the arm. The nerve arises from the posterior chord (C5, C6, C7) of the brachial plexus
Musculocutaneous nerve supplies (BBC) biceps, bracialis and corocabrachialis.
Brachioradialis is supplied by radial nerve.

Musculocutaneous nerve	Muscles of anterior compartment of arm Supplies Biceps, corocabrachialis, brachialis Injury causes loss of elbow flexion and weakness in supination.
Median nerve	Muscles of anterior compartment of forearm Injury to median nerve at wrist causes: Ape thumb deformity Pen test for abductor pollicis brevis Inability to count on fingers with thumb
Axillary nerve	Deltoid and teres minor Injury causes Loss of abduction of shoulder Rounded contour of shoulder is lost Sensory loss over lower half of deltoid	Fracture surgical neck of humerus dislocation of shoulder
Radial nerve	Posterior muscles of arm and forearm Injury causes Saturday night palsy Crutch palsy Wrist drop	Fracture of humeral shaft

USMLE Case Scenario

Deltoid is a thick muscle. It arises from the anterior border and superior surface of the lateral third of the clavicle. Which of the following nerves innervates the deltoid?

Radial
Musculocutaneous
Ulnar
Anterior interosseous c nerve
Cranial nerve XI
Subscapular
Axillary

Ans. 7. Axillary Nerve

Flexors of forearm: Biceps, brachialis, brachioradialis
Extensors of arm: Triceps, Anconeus
Muscles attached to greater tubercle: Supraspinatus, infraspinatus, teres minor
Muscles attached to lesser tubercle: subscapularis
Muscles attached to coracoid process: biceps, short head of biceps
- Abductors of shoulder joint: Deltoid, serratus anterior, trapezius
- Adductors of shoulder joint: pectoralis major, lattismus dorsi

Defective intramembranous ossification
Agenesis of clavicle and deformity of skull cap

Supraspinatus

Infraspinatus

Teres minor

Subscapularis

Frozen shoulder
Dropped shoulder
Chronic supraspinatus tendinitis
Tennis elbow
Golfers elbow
Base pitchers elbow
De quevarians disease
Trigger finger
Mallet finger

Is adhesive capsulitis or periarthritis
Paralysis of trapezius
Is painful arc syndrome
Is lateral epicondylitis
Is medial epicondylitis
Is damage to soft tissues/bones around elbow
Is tenosynovitis of Extensor pollicis brevis and abductor pollicis longus
Is thickening of tendon sheaths at metacarpophalyngeal joint
Is avulsion of extensor tendon of distal interphalangeal joint

Triangular depression formed on the posterolateral side of the wrist and metacarpal I by the extensor tendons passing into the thumb
Historically, ground tobacco (snuff) was placed in this depression before being inhaled into the nose
The base of the triangle is at the wrist and the apex is directed into the thumb. The impression is most apparent when the thumb is extended:
The lateral border is formed by the tendons of the abductor pollicis longus and extensor pollicis brevis;
The medial border is formed by the tendon of the extensor pollicis longus;
The floor of the impression is formed by the scaphoid and trapezium and distal ends of the tendons of the extensor carpi radialis longus and extensor carpi radialis brevis. Structures inside:

Remember essentially:

The radial artery passes obliquely through the anatomical snuffbox
Terminal parts of the superficial branch of the radial nerve pass subcutaneously over the snuffbox
Origin of the cephalic vein from the dorsal venous arch of the hand

Pallor
Pain (Most important sign)
Paralysis
Parasthesias
Pulselessness

Median nerve mostly involved with Deformity: Flexion of wrist, Extension of Fingers at MCP, Flexion at IP and Pronation of forearm. Flexor digitorum profundus and Flexor Pollicis Longus are muscles damaged.

Progressive, Painless, Puckeringor fibrosis of skin of Palmar Fascia with flexion of MCP joints of ring and little fingers

Fall on outstretched hands, Common in elderly women
Distal fragment displaced dorsally, Angulated dorsally, supinated and is also called as ‘Dinner Fork’ Deformity

Also known as washerwoman’s sprain or mother’s wrist is a tendinosis of the sheath or tunnel that surrounds two tendons that control movement of the thumb. (Extensor pollicis brevis and abductor pollicis longus muscles). De Quervain is potentially more common in women; the speculative rationale for this is that women have a greater styloid process angle of the radius. Symptoms are pain, tenderness, and swelling over the thumb side of the wrist, and difficulty gripping. Finkelstein’s test is used to diagnose de Quervain syndrome in people who have wrist pain.

Scaphoid is one of the Carpal bones which undergo fracture commonly as well as avascular necrosis. Avascular necrosis of ‘proximal’ fragment is seen

Injury occurs by fall on outstretched hands. MC site of injury is ‘Waist’

Tenderness in ‘Anatomical snuff box’ maybe seen. Best Radiological view is Oblique view

In absence of Radiological findings, suspect scaphoid fracture. Most common site is between proximal 1/3 and distal 2/3.

Hip joint

Medial rotator of thigh:

Gracilis
Lateral rotators of femur are:

Obturator internus, Obturator externus

Sartorius, Pyriformis

Superior gemellus, inferior gemellus

Abductors of the hip include the gluteus medius and gluteus maximus
Adductors of the hip include the adductors longus, brevis and magnus
Extensors of hip include gluteus maximus
Internal (medial) rotators of the hip include gluteus medius, minimus, Tensor facia lata
Lateral rotators: quadriceps femoris (rectus femoris, vastus lateralis, medialis and intermedius)
Iliopsoas is flexor of hip

Remember:

Tensor fascia lata is extensor of knee, Abductor and medial rotator of hip. (Imp) TEAM
Ilio tibial tract is flexor, external rotator, abductor of hip. (Imp)

Knee Joint

Extensor of knee: quadriceps femoris
Flexion of knee: long head of biceps femoris. Semimembranosus, semitendonosus, ischial head of adductor magnus
Medial rotation: Semimembranosus, semitendonosus, popliteus
Lateral rotation: biceps femoris

Meralgia Parasthetica Lateral cutaneous nerve of thigh
Anterior Tarsal Tunnel Syndrome: Deep peroneal nerve
Tarsal Tunnel syndrome: Tibial nerve
Joggers Foot: Medial plantar nerve
Hip Pointer: Iliac Crest
Tennis Leg: Gastrocnemius Soleus strain

Ileo femoral ligament is ligament of Bigelow
It is the strongest ligament
It prevents hyperextension of hip
Pain of hip is referred to knee joint

Knee

Coronary ligament is present between menisci and tibial condyle
There is other Coronary ligament in liver
Posterior dislocation of Femur is prevented by anterior cruciate ligament
Posterior cruciate ligament prevents posterior dislocation of Tibia
Ligament of Humphery and Wrisberg are anterior and posterior meniscofemoral ligaments

MENISCAL TEAR

Medial meniscus is 20 times more prone to injury than lateral meniscus. The medial meniscus is firmly adherent to the deep part of tibial collateral ligament. In forceful strains (adduction and lateral rotation of the femur over the tibia with the foot firmly placed on the ground) the medial meniscus gets torn. It is because:
The medial collateral ligament does not allow the meniscus to move away from under the femoral condyle
It gets compressed crushed between femoral and tibial condyles that are moving with great force
Part of torn cartilage may get displaced. This small piece floats in the joint cavity. It may get lodged between femoral and tibial condyles causing locking of knee joint in flexed position

Obturator artery
Medial circumflex artery
Lateral circumflex artery
Superior gluteal artery
Inferior gluteal artery

USMLE Case Scenario

A 88-year-old osteoporotic female who was a chronic smoker stumbled and fell. The right leg is shortened and externally rotated with marked loss of range of movements at hip joint

The most likely cause is: Fracture Neck of femur

Femoral nerve through nerve to rectus femoris
Anterior division of obturator nerve
Nerve to quadrates femoris
Superior gluteal nerve

Genicular branches of popliteal artery
Genicular branches of femoral artery
Genicular branches of lateral circumflex femoral artery
Branches of anterior tibial artery
Branches of posterior tibial artery

Femoral nerve through nerve to vasti
Posterior division of obturator nerve
Sciatic nerve through tibial and common peroneal nerves

Adductor compartment of thigh: Obturator nerve
Flexor compartment of thigh: Femoral nerve
Posterior compartment of thigh (hamstrings); tibial part of sciatic nerve
Gluteal region: superior and inferior gluteal nerves
Anterior compartment of leg: Deep peroneal nerve
Lateral compartment of leg: Superficial peroneal nerve
Posterior compartment of leg: Tibial nerve

Femoral nerve (posterior division of L2, L3, L4)	Anterior compartment of high
Obturator nerve (anterior division of L2, L3, L4)	Medial compartment of thigh
Tibial nerve	Posterior compartment of thigh Posterior compartment of leg
Common peroneal nerve	Short head of biceps femoris
Superficial peroneal nerve	Lateral compartment of leg Injury causes loss of eversion of foot
Deep peroneal nerve	Anterior compartment of leg Injury causes foot drop

Superior gluteal nerve	Gluteus minimus, gluteus medius, tensor fascia lata NOT Gluteus maximus. Injury Causes
(Very Important)	loss of abduction of limb
	Impairment of gait Patient cannot keep pelvis level when standing on one leg. Tredlenburgs sign +
Inferior gluteal nerve	Gluteus maximus. Injury causes: Weakened hip flexion Difficulty rising from sitting position.

Q angle: Quadriceps angle is formed by line of pull of quadriceps femoris muscle and that of ligamentum patellae as they intersect at center of patella. more pronunced in females
Genu valgum (knock knee) angle < 165°
Genu varum (bow legs) angle > 180°

The Common Peroneal Nerve

Branches into the superficial and deep peroneal nerves, which supply the muscles of the anterior compartment of the leg and cutaneous areas of the distal anterior leg, dorsum of the foot, and most of the digit

The Tibial Nerve

Supplies all the muscles in the posterior compartment of the leg (e.g. tibialis posterior, flexor digitorum longus, gastrocnemius, and soleus)

Ankle: Dorsiflexion, Plantar flexion
Subtalar joint: Inversion, eversion
Mid tarsal joint: Forefoot adduction and abduction

Plantar flexion	Gastrocnemius, soleus
Dorsiflexion	Tibialis anterior
Inversion	Tibialis anterior, tibialis posterior
Eversion	Peroneus longus, peroneus brevis

It is related to the neck of fibula and winds around it
It is the smaller terminal branch of Sciatic nerve
It pierces peroneus longus
It divides into superficial and deep peroneal nerves and supplies the anterior and lateral compartments of leg
Injury to CPN produces foot drop
It is subcutaneous
It is the most common nerve in lower limb to get injured

Dorsiflexion	Tibialis anterior Extensor digitorum longus Extensor hallucis longus Peroneus tertius
Plantar flexion	Gastrocneimus Soleus Plantaris Tibialis posterior Flexor hallucis longus Flexor digitorum longus
Inversion	Tibialis posterior Flexor hallucis longus Flexor digitorum longus
Eversion	Peroneus longus Peroneus brevis Peroneus tertius

Biceps	C5, C6
Supinator	C5, C6
Pronator	C5, C6
Triceps	C6, C7
Cremaster	L1, L2
Knee	L2, L3, L4
Plantar	L5 S1
Ankle	S1, S2
Anal, Bulbocavernous	S3, S4

The protuberant part of the human breast is generally described as overlying the 2nd to the 6th ribs, and extending from the lateral border of the sternum to the anterior axillary line. Actually, a thin layer of mammary tissue extends considerably farther from the clavicle above to the 7th or 8th ribs below, and from the midline to the edge of latissimus dorsi posteriorly.
The Axillary tail of Spence in the breast is of considerable surgical importance. In some normal cases it is palpable, and in a few it can be seen premenstrually or during lactation. A well-developed axillary tail is sometimes mistaken for a mass of enlarged lymph nodes or a lipoma.

43The lobule is the basic structural unit of the mammary gland. The number and size of the lobules vary enormously: they are most numerous in young women. From 10 to over 100 lobules empty via ductules into a lactiferous duct of which there are from 15 to 20. Each lactiferous duct is lined by a spiral arrangement of contractile myoepithelial cells and is provided with a terminal ampulla — a reservoir for milk or abnormal discharges.
The ligaments of Cooper are hollow conical projections of fibrous tissue filled with breast tissue, the apices of the cones being attached firmly to the superficial fascia and thereby to the skin overlying the breast. These ligaments account for the dimpling of the skin overlying a carcinoma.
The areola contains involuntary muscle arranged in concentric rings as well as radially in the subcutaneous tissue. The areolar epithelium contains numerous sweat glands and sebaceous glands, the latter of which enlarge during pregnancy and serve to lubricate the nipple during lactation (Montgomery’s tubercles).
The nipple is covered by thick skin with corrugations. Near its apex lie the orifices of the lactiferous ducts. The nipple contains smooth muscle fibers arranged concentrically and longitudinally; thus is an erectile structure which points outwards. Lymphatics of the breast drain predominantly into the axillary and internal mammary lymph nodes. The axillary nodes receive approximately 75 percent of the drainage and are arranged in the following groups.

Internal thoracic artery
Intercostal artery
Lateral thoracic artery

Lateral, along the axillary vein
Anterior, along the lateral thoracic vessels
Posterior, along the subscapular vessels
Central embedded in fat in the center of the axilla
Interpectoral, a few nodes lying between the pectoralis major and minor muscles
Apical, which lie above the level of the pectoralis minor tendon in continuity with the lateral nodes and receive the efferents of all the other groups

The apical nodes are also in continuity with the supraclavicular nodes and drain into the subclavian lymph trunk which enters the great veins directly or via the thoracic duct or jugular trunk. The sentinal node is that lymph node designated as the first axillary node draining the breast.

The internal mammary nodes are fewer in number and lie along the internal mammary vessels deep to the plane of the costal cartilages

Mondor’s disease is thrombophlebitis of the superficial veins of the breast and anterior chest wall (although it has also been encountered in the arm).

Familial breast cancer Recent developments in molecular genetics and the identification of a number of breast cancer predisposition genes (BRCA1, BRCA2 and TPS3). These women have a risk of developing breast cancer two to 10 times above baseline.

Lymph nodes below Pectoralis Minor Level 1
Lymph nodes behind Pectoralis Minor Level 2
Lymph nodes above Pectoralis Minor Level 3
The principal nodes which drain the breast are: Axillary Group of Lymph nodes
About 70 -75% of lymph from breast drains into Axillary group of Lymph nodes, 20% into internal mammary group of Lymph nodes and 5% into posterior intercostal group of lymph nodes
Among the Axillary Group Chief is the Anterior group
Rotters nodes are interpectoral nodes
Absence of sternal head of pectoralis major: Polands syndrome

Vena caval opening:
- Thoracic 8 level
- Inferior vena cava
- Rt phrenic nerve
Esophageal opening:
- Thoracic 10 level
- Esophagus
- Vagus nerves
- Esophageal branch of it gastric artery
Aortic opening:
- Thoracic 12 level
- Aorta
- Thoracic duct
- Azygous vein

The ducts deferens
Testicular and cremastric arteries
Artery of vas
The pampiniform plexus of veins
Lymph vessels from testis
Genital branch of Genitofemoral nerve
Remains of processus vaginalis

Rectus abdominis and pyramidalis muscle
Superior epigastric artery and inferior epigastric artery
Superior epigastric vein and inferior epigastric vein
Lower five intercostal nerves and subcostal nerve

Uterine tube
Round ligament of uterus, ligament of ovary
Uterine vessels, ovarian diseases
Uterovaginal, ovarian nerve plexus
Epoophoron, Paroophoron
Lymph vessels, lymph nodes

Perianal space
Ischiorectal space
Lunate fascia
Pudendal canal

Femoral artery
Saphanous nerve
Nerve to vastus medialis

Esophageal opening lies in muscular part of diaphragm
Vena caval lies in central tendon of diaphragm
Aortic opening is not a true opening but an osseo aponeurotic opening
Greater and lesser splanchnic nerves pierces each crus of diaphragm
Lt crus is also pierced by hemi azygous vein
Sympathetic chain passes behind medial arcuate ligament
Subcostal nerves vessels pass behind lateral arcuate ligament
Superior epigastric vessels and lymphatics pass through Foramen of Morgagni (Larrys space)
Musculophrenic vessels pierce the diaphragm
Hernia does not occur through vena caval opening
Bochaldeks hernia occurs through posterolateral part of diaphragm
Morgagni hernia occurs anteriorly on right usually
Remember Accessory phrenic nerve is commonly a branch from the nerve to subclavius

Distance from Incisor	Landmark
6 inches	Pharyngoesophageal junction
9 inches	Aortic arch crossing
11 inches	Left bronchus
15 inches	Pierces diaphragm

Length 25 cm
Commences at lower end of cricoid
Has squamous epithelium
Toughest layer is muscularis
No serosa

Right coronary artery arises from anterior aortic cusp
Left coronary arises from posterior aortic cusp
Posterior interventricular artery determines coronary dominance
46In case it arises from right coronary artery, right dominance
In case it arises from left coronary, left dominance
Right Coronary artery mostly supplies SA node, AV node, AV bundle
The SA node is usually supplied by Right coronary artery and Right Vagus
The AV node is usually supplied by Right coronary artery and Left vagus
Sympathetic innervation is by T2-T6
Maximum (90%) of venous drainage of Heart goes to Coronary Sinus
In fetal life left sided svc drains into coronary sinus

Great Cardiac Vein follows Anterior Interventricular artery
Middle Cardiac Vein follows Posterior Interventricular artery
Small Cardiac Vein follows Rt Marginal artery

Inferior surface of heart is formed by Rt and Lt ventricle
Base of heart is formed by Rt and Lt atrium
Part of heart lying close to esophagus: Lt atrium

Structures Present In:

Musculi pectinati: Atria of heart
Trabeculae cornea: Rt ventricle of heart
Moderator band/Septomarginal trabeculae: right ventricle
Coronary sinus, SVC, IVC: open in Right atrium
SA node is located in: Rt Atrium
Whole of conducting system is mostly supplied by rt coronary artery except Right bundle branch (supplied by left coronary artery)
Holmes heart: single ventricle

It is the largest venous channel of the heart about 3 cms. It located in left posterior coronary sulcus

It is a remnant of left horn of sinus venosus = while the right horn gets incorporated into right atrium

It opens into the right atrium of the heart through an orifice of coronary sinus and has a valve called the Thebesian valve. It receives:

Great cardiac vein
Middle cardiac vein
Small cardiac vein
Right marginal vein
Oblique vein of left atrium
Right marginal vein

Also called as Pecquets duct
Beaded in appearance
18 inches in length
It is the largest lymphatic pathway in body
The duct commences in the abdomen as an elongated lymph sac of the cisterna chylli is: Thoracic duct
Begins from cisterna chyli at the level of T12 vertebrae
Injury to thoracic duct by trauma leads to chylothorax

Vascular segment
Independent
Bronchial artery supplies till respiratory bronchiole
Largest subdivision of lobe

Remember

Because the right main bronchus is wider and more vertical than the left, foreign objects are more likely to be aspirated into the right main bronchus. The superior segmental bronchus of the lower lobar bronchus is the only segmental bronchus that exits from the posterior wall of the lobar bronchi. Therefore, if a patient is supine at the time of aspiration, the object is most likely to enter the superior segmental bronchus of the lower lobe.

Smallest functional unit of lung is lobule
Blood supply of lung tissue proper is by Bronchial arteries
Bronchial arteries are branches of descending: Thoracic Aorta
They supply nutrition to bronchial tree and pulmonary tissue up to respiratory bronchiole
Segments distal to respiratory bronchiole are supplied by branches from pulmonary vessels
On the right side there is only one BA arising indirectly from descending Thoracic Aorta
On the Left side there are two BA arising directly from descending Thoracic Aorta
Bronchial arteries are responsible for Hemoptysis
Pulmonary arteries carry deoxygenated blood
Pulmonary veins carry oxygenated blood
Sequestered segments are supplied by systemic circulation

Azygos means unpaired. Azygos lobe maybe seen on the right lung
It is seen as a result of developmental anomaly related to lung bud and posterior cardinal vein
The posterior cardinal vein (future azygos vein) gets embedded in the substance of lung which passes as lung bud below the arch formed by posterior cardinal vein
The part of lung medial to the vein forms the azygos lobe

It is a hemolymphatic organ:
The second largest organ of the reticuloendothelial system
It is located in the posterior left upper quadrant of the abdomen (left hypochondrium) where its relationships to the diaphragm, stomach, pancreas, left kidney, and splenic flexure of the colon are maintained by suspensory ligaments. The splenophrenic, splenorenal, and splenocolic ligaments are usually relatively avascular and their transection allows the spleen to be displaced medially and anteriorly
The ‘Gastrosplenic ligament’ extends from the greater curvature of the body and fundus of the stomach to the spleen, contains the short gastric arteries and veins
The ‘Splenorenal’ ligament (Lienorenal) and attached to the spleen at the hilum: Splenic artery and vein, lymphatic structures, and often the tail of the pancreas
48The arterial supply to the spleen is derived from the celiac artery from both the splenic artery and the short gastric arteries, which usually arise as branches of the gastroepiploic or the splenic arteries
The splenic vein is formed by a coalescence of polar veins in the splenic hilum and courses with the splenic artery along the dorsal surface of the pancreas to enter the portal system.

Starts from gastroesophageal junction to the pylorus

It is bounded on the left by the spleen and on the right by the liver

The blood supply to the stomach is extensive

Left gastric artery, which supplies the upper lesser curvature of the stomach from celiac trunk
The right gastric artery branches off the hepatic artery, which originates from the celiac axis; it supplies blood to the distal lesser curvature
The left gastroepiploic artery is a branch off the short gastric vessels; it comes from the splenic and therefore originally from the celiac axis
The right gastroepiploic artery branches off the gastroduodenal artery, which comes originally from the hepatic artery and therefore from the celiac axis

The venous drainage of the stomach empties in a variety of directions, including venous tributaries along the esophagus, veins that flow with the short gastrics to the splenic vein, and venous drainage that is carried toward the duodenum and toward the portal vein

Nerve supply is predominantly by the vagus

An anterior (left) and posterior (right) vagus nerve courses with the esophagus until the gastroesophageal junction

The ‘criminal’ nerve of Grassi is the first branch of the posterior vagal nerve innervating the greater curvature fundus. At the junction of the fundus and the antrum of the stomach, the vagal nerves branch and innervate the antrum. This vagal branch point is called the crow’s foot

The lesser sac is bounded ventrally by the stomach and is an important location during operation, in that it is a frequent space for fluid collection and is an important plane for the exposure of gastric anatomy.

The duodenum extends from the pylorus about 20 to 30 cm and ends at the ligament of Treitz, which is where the jejunum begins. This is marked by adhesive bands between the duodenal-jejunal junction and the retroperitoneum on the left side of the abdomen

The duodenum is divided into four anatomic regions:
The first portion, or the cap or bulb
The second portion, or the descending duodenum
The third, or transverse, portion; and the
Fourth, or ascending, portion

The duodenal cap lies just beyond the pylorus. Ninety percent of ulcers occur in the duodenal cap region.

The gastroduodenal artery lies directly behind the duodenal cap, and penetrating ulcers into the pancreas initially erode through the gastroduodenal artery, accounting for the massive bleeding that occurs with these ulcers.

The second (descending) portion of the duodenum: The ampulla of Vater and the minor papilla both enter into the duodenum in this portion. The second portion of the duodenum is approximately 10 cm in length.

The third and fourth portions of the duodenum (transverse and ascending portions) are mostly retroperitoneal.

The third portion is attached to the uncinate process and crosses the abdomen and over the aorta.

Compression of the junction of the third and fourth portions of the duodenum by the angle of the SMA and the aorta is called the SMA syndrome.

49The fourth portion of the duodenum blends into the jejunum at the ligament of Treitz, which attaches this junction to the retroperitoneum. Mobilization of the ligament of Treitz is necessary in duodenal resections. The ligament is often composed of small strands of striated muscle that eventually extend to the crus of the diaphragm.

‘Kerckring’s folds’ The mucosal surface of the small intestine contains numerous circular mucosal folds called the plicae circulares (valvulae conniventes, or valves of Kerckring) of the duodenum begin just beyond the cap and continue throughout the duodenum. The concentric folds of Kerckring are approximately 1 to 2 mm thick and 2 to 4 mm high. They are taller and more numerous in the distal duodenum and proximal jejunum, becoming shorter and fewer distally.

Small intestine	Large intestine
About 6 -7 meters in length	About 180 cms in length
Small diameter	Larger diameter
Mucosa has villi and crypts	Mucosa hascrypts but no villi
Paneth cells present	Paneth cells absent
Less goblet cells	More goblet cells
Brunner’s glands in duodenum present Peyers patches in ileum present	Both absent
Sacculations absent	Sacculations present
Appendices epiploicae absent	Appendices epiploicae present
Tenia absent	Tenia present

LEFT GASTRIC ARTERY — Esophageal branch, gastric branch
COMMON HEPATIC ARTERY — Right hepatic, left hepatic, Gastroduodenal artery→ supraduodenal, right gastroepiploic, superior pancreaticoduodenal artery
SPLEENIC ARTERY — Short gastric, left gastroepiploic, pancreatic branches

A Meckel’s diverticulum, a true congenital diverticulum
It is a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct) and is the most frequent malformation of the gastrointestinal tract
Meckel’s diverticulum is located in the distal ileum, usually within about 60-100 cm of the ileocecal valve
It is typically 3-5 cm long, runs antimesenterically and has its own blood supply
It is a remnant of the connection from the umbilical cord to the small intestine present during embryonic development

2% (of the population)
2 feet (from the ileocecal valve)
2 inches (in length)
2% are symptomatic
2 types of common ectopic tissue (gastric and pancreatic)
Most common age at clinical presentation is 2
Males are 2 times as likely to be affected

50

Anal canal above Dentate Line	Anal Canal Below Dentate Line
Endodermal	Ectodermal
Cuboidal epithelium	Stratified squamous
Superior Rectal Artery	Inferior Rectal Artery
Superior Rectal Vein	Inferior Rectal Vein
Internal Iliac group of lymph nodes	Superficial inguinal group of lymph nodes
Pain insensitive	Pain sensitive

Lies in the right upper quadrant of the abdomen
It is the largest gland in the body, it weighs approximately 1500 gm
The gallbladder lies on the dorsal surface of the liver in a transpyloric plane
A peritoneal membrane (Glisson’s capsule) covers the liver
The superior surface of the liver conforms to the undersurface of the right diaphragm. The relations of the inferior surface of the liver are the duodenum, colon, kidney, adrenal gland, esophagus, and stomach. Peritoneum invests the entire liver except for a bare area under the diaphragm on the posterosuperior surface adjacent to the inferior vena cava and hepatic vein.

The falciform ligament, which attaches the liver to the anterior abdominal wall from the diaphragm to umbilicus and incorporates the ligamentum teres hepaticus
The anterior and posterior right and left coronary ligaments, which in continuity with the falciform ligament connect the diaphragm to the liver. The lateral aspects of the anterior and posterior leaves of the coronary ligaments fuse to form the right and left triangular ligaments
The gastrohepatic and hepatoduodenal ligaments, which consist of the anterior layer of lesser omentum and are continuous with the left triangular ligament. The hepatoduodenal ligament contains the hepatic arteries, portal vein, and extrahepatic bile ducts. It forms the anterior boundary of the epiploic foramen of Winslow and the communication between the greater and lesser peritoneal cavities.

Right
Left
Quadrate
Caudate

The portal vein provides about three fourths of the liver’s blood supply
The combination of the superior mesenteric and splenic veins forms the portal vein, behind the neck of the pancreas
The portal vein then passes superiorly, posterior to the first part of the duodenum at the level of the second lumbar vertebra
Portal vein is 1 to 3 cm in diameter and 5 to 8 cm in length before dividing into right and left branches at the portal hepatis
The portal vein usually passes behind the bile duct and hepatic artery in the hepatoduodenal ligament
The portal trunk divides into left and right hepatic branches in the portal fissure. The left branch of the portal vein is longer
The portal vein divides into small veins and venules, which finally enter hepatic sinusoids
The portal vein has no valves

Numerous tributaries of the portal vein connect outside the liver with the systemic venous system. Under normal circumstances these communications have little physiologic significance. However, if portal hypertension develops, these rudimentary portosystemic communications develop into large channels with increased collateral flow.

The submucosal veins of the proximal stomach and distal esophagus, which can receive blood from the coronary and short gastric veins to drain into the azygous veins (high blood flow through this pathway produces gastric varices, esophageal varices, or both)
Umbilical and periumbilical veins, recanalized from the obliterated umbilical vein in the ligamentum teres hepaticus, and which may cause caput medusae or the loud Cruveilhier-Baumgarten bruit
Tributaries of the inferior mesenteric vein, which include the superior hemorrhoidal veins that communicate with the middle and inferior hemorrhoidal veins of the systemic circulation and may cause large hemorrhoids; and
Other retroperitoneal communications, including connections to the renal and adrenal veins.

The circular smooth muscle fibers in the ampulla of Vater area constitute the sphincter of Oddi, which regulates the flow of bile from the liver into the duodenum

The three principal parts of the sphincter of Oddi are:

The sphincter of the choledochus (i.e. the circular muscle fibers surrounding the intramural and submucosal bile duct);
The pancreatic sphincter, which consists of a muscular septum between the bile and pancreatic ducts;
Ampullary sphincter: The ampullary sphincter, the most important component of the sphincter of Oddi, includes a layer of longitudinal muscle fibers that help prevent reflux of intestinal contents into the ampulla

Relaxation of the ampullary sphincter may promote reflux into the pancreatic duct.

The gallbladder, a pear-shaped (pyriform), distensible appendage of the extrahepatic biliary system

Capacity: 30 to 50 ml of bile

Parts: It has a fundus, body, and neck

The duct of gallbladder cystic duct varies in length and usually contains spiral valves of Heister that regulate bile flow

Enlargement of the neck of the gallbladder such as from a stone may form a pouch (Hartmann’s pouch)

The triangle bounded by the cystic duct, common hepatic duct, and inferior border of the liver is the Triangle of Calot

The gallbladder receives its blood supply from the cystic artery, which originates from the right hepatic artery

Venous drainage of the gallbladder enters principally into the portal vein

The lymphatics drain into cystic duct nodes near the superior aspect of the cystic duct. (Cystic Lymph node of Lund)

It is a surgical landmark used to identify important structures during cholecystectomy, is bounded by the cystic duct, the common hepatic duct, and the inferior border of the liver

The right hepatic and cystic arteries are located within it and anomalous structures often pass through it

Moynihans Hump: An abnormal bend in the course of the right hepatic artery, throwing it into the configuration of a caterpillar hump, (Moynihan’s hump) invites injury unless it is carefully dissected free

It is a retroperitoneal organ, lying posterior to the stomach and lesser omentum
It extends from the duodenal C loop to the hilum of the spleen
The gland has a distinctive yellow/tan/pink color and is multilobulated
The gland is divided into four portions:
1. The head (which includes the uncinate process)
2. The neck
3. The body and
4. The tail
The head of the gland extends to the right of the neck, lying within the confines of the duodenal C loop; it includes the posteroinferior extension arising from the ventral primordium, designated the uncinate process. The uncinate process extends posterior to the superior mesenteric vein, ending at the right margin of the superior mesenteric artery. The body of the pancreas lies immediately to the left of the neck; the tail of the pancreas extends to the left of the body into the splenic hilum.
The head of the pancreas is intimately associated with the second portion of the duodenum, and these two structures are jointly supplied by two arterial arcades known as the anterior and posterior pancreaticoduodenal arteries. These arteries originate from the superior and inferior pancreaticoduodenal vessels as branches of the celiac axis and superior mesenteric artery, respectively. The distal body and tail of the pancreas are supplied by short branches of the splenic and left gastroepiploic arteries. Within the posterosuperior and posteroinferior aspects of the body of the pancreas lie the superior and inferior pancreatic arteries, respectively.
Veins draining the pancreatic parenchyma eventually terminate in the portal vein, which arises posterior to the neck of the pancreas at the junction of the splenic and superior mesenteric veins

Multiple lymph node groups drain the pancreas

From the head of the gland, nodes in the pancreaticoduodenal groove communicate with subpyloric, portal, mesocolic, mesenteric, and aortocaval nodes
Lymphatics in the body and tail of the pancreas drain to retroperitoneal nodes in the splenic hilum or to celiac, aortocaval, mesocolic or mesenteric nodes

Bean shaped
Retroperitoneal
Right kidney is lower than left (but right suprarenal is higher than left.)
Each kidney is 9 to 15 cm long, 4 to 5 cm wide and approximately 3 cm thick. They are located on each side of the vertebral column between the parietal perineum and the fascia and musculature of the posterior abdominal wall and are embedded in a variable amount of fat and surrounded by a layer of fascia (Gerota’s fascia)
They lie on the side of the psoas muscle
They are not parallel, with the upper poles being approximately 2 cm from the midline and the lower poles approximately 3.5 cm from the midline
Coverings of Kidney (From inside to out)
- Fibrous capsule
- Perinephric fat
- Renal fascia with 2 layers
  - Anterior layer of Toldts Fascia
  - Posterior layer of fascia of Zuckerkandl
- Pararenal Fat

3 parts of diaphragm: Medial arcuate ligament, Lateral arcuate ligament, Diaphragm
3 muscles: Psoas major, quadrates lumborum, transverses abdominis
3 nerves: Subcostal, iliohypogastric, ilioinguinal nerves
Right kidney: 12th rib
Left kidney: 11th and 12th rib

25 cm long (PGI)
Totally retroperitoneal
It enters true pelvis after crossing iliac vessel

Starts at the hilum
Changes its direction at the ischial spine
Penetrates the bladder wall without any valve
Enters the bladder at the lateral angle of the trigone
Enters pelvis in front of bifurcation of common iliac artery

Are bilateral retroperitoneal organs located on the superior medial aspect of the upper pole of each kidney
Each gland weighs approximately 4 gm. The left adrenal is larger and flatter
The normal adrenal cortex is bright yellow and thicker than the red-brown medulla.

Superior suprarenal artery: branch of inferior phrenic artery
Middle suprarenal artery: branch of abdominal aorta
Inferior suprarenal artery: branch of renal artery

The left adrenal vein empties primarily into the left renal vein but may occasionally drain directly to the vena cava

Lymphatic plexuses within the subcapsular portion of the adrenal cortex and the adrenal medulla drain to the adjacent para-aortic subdiaphragmatic and renal lymph nodes.

Relations at hilum of kidney (Anterior to Posterior) ‘VAP’

Renal vein
Renal artery
Renal pelvis

Relations at Femoral Triangle (From Medial to Lateral) 'VAN’

Femoral vein
Femoral artery
Femoral nerve

54Intercostal space (From Above Downwards) ‘VAN’

Intercostal vein
Intercostal artery
Intercostal nerve

Cubital Fossa (From Medial to lateral side). ‘MBBR’

Median nerve (Medial aspect)
Brachial artery
Biceps tendon
Radial nerve
Lateral boundary by brachioradialis muscle.

It is male gonad
Two oval structures are average 4 to 5 cm in length and 2.5 to 3.5 cm in width in the normal adult male
10–15 gms in weight (Indians average)
Testis arises from the genital ridge

Tunica vaginalis
Tunica albugenia
Tunica vasculosa
Blood supply is by testicular artery which is a branch of abdominal aorta
Venous drainage of the testis is through the pampiniform plexus to the spermatic vein, which is usually single and emerges from the upper end of the cord and then follows the internal spermatic artery through the retroperitoneum. On the right the spermatic vein empties into the vena cava below the right renal vein, whereas on the left the spermatic vein empties into the main renal vein. Increased hydrostatic pressure, particularly on the left, may result in dilatation of the pampiniform venous plexus, producing a varicocele
The lymphatic drainage of the testis is through the spermatic cord and the inguinal canal and then to the common iliac and preaortic and paraortic nodes, with the latter communicating across the midline at the level of the kidneys and also with the mediastinal and supraclavicular chains
Histologically, there are two principal portions of the testis: The seminiferous tubules, which are responsible along with the Sertoli cells for spermatogenesis, and the interstitial or Leydig cells, which elaborate androgenic hormones, predominantly testosterone

Iliac Fossa: 3rd month
Deep Inguinal Ring: 7th month
Pass through Inguinal Canal: 7th month
At Superficial Inguinal ring: 8th month
Enter Scrotum: 9th month

Are coiled structures each containing a single epididymal tubule 12 to 19 feet long and attached to the posterolateral surface of each testis

Remember:

From the tails of the epididymi sperm are transmitted into the vasa deferentia, which are direct continuations of the duct of the epididymi passing up the spermatic cord, across the inguinal canal, and then retroperitoneally to the ampulla of the seminal vesicles, with which they conjoin to form an ejaculatory duct on each side. The ejaculatory duct then empties directly into the prostatic urethra.

The principal blood supply for the epididymis is from the internal spermatic artery. Venous drainage corresponds to the arterial supply, and the lymphatic drainage of the epididymis parallels that of the testis. The prime function of the epididymis is not only as a conduit for spermatozoa but also for biochemical and functional maturation and ultimate storage.

Ductus deferens/Vas Deferens

It is 18 inches in length. The vas deferens is an easily discernible structure within the scrotum and spermatic cord because it is a heavily muscled tubular structure

Spermatic Cord

The spermatic cord, suspending each testis and its attached epididymis, is composed of the vas deferens, the internal spermatic artery, the external spermatic artery, the pampiniform plexus of veins, the lymphatic drainage system of the contents of the scrotum, and the autonomic nerve supply to the testis. In addition, the cord is surrounded by fibers of the cremasteric muscle, which assist by contraction and relaxation in the maintenance of optimal testicular temperature and provide for testicular retraction with sexual excitation or in the primitive fright reaction.

The ducts deferens
Testicular and cremastric arteries
Artery of vas
The pampiniform plexus of veins
Lymph vessels from testis
Genital branch of genitofemoral nerve
Remains of processus vaginalis

The scrotal sac, consisting of two lateral compartments fused in the midline encloses the testes, epididymi, and terminal portions of the spermatic cords. The dartos, consisting of elastic fibers, connective tissue, and smooth muscle fibers, is attached to the corrugated skin of the scrotum, rich in sebaceous glands, and provides for muscular contraction of the scrotal sac in response to temperature changes or sexual excitation. The principal function of the scrotum is to aid in temperature control of the testes for optimal spermatogenesis, which takes place at temperatures several degrees lower than those in the intra-abdominal cavity
The blood supply of the scrotum comes from the deep pudendal branches of the femoral artery and branches of the internal pudendal artery
The lymphatics of the scrotal halves anastomose freely, surround the penis, and drain to the inguinal and femoral nodes. There are no connections between the lymphatics of the scrotum and the testes; the scrotal lymphatics do not accompany the pudendal vessels.

Are paired, monotubular, convoluted structures lying beneath the base of the bladder and trigone. Posteriorly they are invested by Denonvilliers’ fascia, which separates them from the anterior wall of the rectum
The two seminal vesicles fuse immediately with the ampullae of the vasa, forming the ejaculatory ducts, which open into the prostatic urethra at the level of the verumontanum. The seminal vesicles secrete a mucoid vehicle for the spermatozoa and also elaborate the body’s only source of fructose, which is used as an essential nutrient for maintenance of spermatozoal viability.

It is a fibromuscular, glandular organ that surrounds the neck of the urinary bladder and the proximal portion of the male urethra. The gland is supported anteriorly by the puboprostatic ligaments, inferiorly by the genitourinary diaphragm (external urinary sphincter), and posteriorly by the rectal wall, which is separated from the prostate by an obliterated pelvic reflection of the peritoneum called Denonvilliers’ fascia.
The prostate consisting of two portions: an anterior (inner) group of glands intimately associated with the urethra and a posterior (outer) portion of more fibromuscular character
Arterial supply: The inferior vesical and internal pudendal arteries provide the blood supply to the prostate, entering the gland posterolaterally at the vesical neck
Venous drainage of the prostate is complex and diffuse, with plexuses over the anterior and lateral portions of the gland that drain into the internal iliac veins
Intercommunicating lymphatics of the prostate, bladder, seminal vesicles, vasa deferentia, and rectum provide drainage into both the internal and external iliac systems as well as the sacral promontory nodes
Zones of Prostate:
These zones have physiologic and surgical significance because Benign enlargement of the prostate (BHP) occurs in the transition or periurethral zone and Malignancy develops in the majority of cases in the Peripheral zone.

18-20 cms in length with 3 parts

Prostatic (3 cms semilunar)
Membranous (2 cms stellate)
Spongy/penile (15 cms slit shaped)

Prostatic part is widest and more dilatable part

Contains:

Veru montanum (urethral crest)
Colliculus seminalis
Prostatic sinuses
Prostatic utricle (analogous to uterus/vagina of females)

Cowper’s Glands: (Bulbourethral glands of Cowper) are small, paired glands lying between the layers of the urogenital diaphragm at the junction of the bulbous and membranous portions of the urethra. The ducts of the glands empty distally into the bulbous urethra traversing the corpus spongiosum. The secretions from this gland not only act as a lubricant but may also have factors that aid in seminal fluid coagulation after ejaculation.

Organ of copulation and excretion of urine
It consists of two parallel erectile tissues as the corpora cavernosa, which are situated dorsolaterally, and the corpus spongiosum, which invests the urethra ventrally, terminating distally in the erectile glans penis
Each corpus cavernosum and the corpus spongiosum are enveloped in fascial sheaths, and all three corpora are surrounded by Buck’s fascia
The blood supply of the penis is through the dorsal arteries derived from the internal pudendal arteries, which are branches of the internal iliac artery
The venous drainage is through the dorsal veins, with the superficial dorsal vein emptying into the saphenous vein, and the deep dorsal vein emptying into the prostatic plexus known as the plexus of Santorini
Penile erection is induced by the engorgement of the erectile tissues of the corpora, principally the corpora cavernosa
Lymphatic drainage of the penis is abundant. The lymphatics from the shaft of the penis, the corpora cavernosa, and the skin pass through the superficial and deep inguinal nodes, communicating with the iliac nodes.
57Lymphatic drainage of the glans penis drains into deep inguinal nodes and rest of the penis drains into superficial inguinal nodes
The skin of the penis differs considerably from other skin of the body in its paucity of sebaceous glands, its elasticity, and its extensive blood supply.

The bulbourethral glands secrete mucus for lubrication
The epididymis concentrates and stores sperm for ejaculation
The prostate gland secretes alkaline fluid to neutralize vaginal pH and induces clotting of the semen
The seminal vesicles produce fructose, citric acid, prostaglandins, and fibrinogen. These comprise about 60% of the volume of semen
The ampulla is the end of the vas deferens
The bulbourethral glands secrete mucus for lubrication
The epididymis concentrates and stores sperm for ejaculation
The prostate gland secretes alkaline fluid to neutralize vaginal pH and induces clotting of the semen

The seminal vesicles produce fructose, citric acid, prostaglandins, and fibrinogen. These comprise about 60% of the volume of semen.

The vagina is a female copulatory organ. It is a muscular tube lined with stratified squamous epithelium. The adult vagina measures 12 to 13 cm in-depth. In virgin lower end of vagina is closed partially by annular fold of mucus membrane called hymen which gets distorted after intercourse forming rounded elevations called caruncle hymenale.

It is the lower cylindrical portion of the uterus
The cervix, is a fibromuscular organ covered with stratified squamous epithelium. The walls of cervix show mucosal folds called arbor vitae
The squamocolumnar junction is the most common site of origin of squamous cell carcinoma
The endocervical canal is lined by columnar epithelium, and racemose glands, lined with similar epithelium, are found in the fibromuscular stroma. Such glands, if obstructed, may form nabothian cysts on the cervical surface
The nulliparous cervical os is round.

The uterus is a hollow, fibromuscular-walled organ between the bladder
The normal position of uterus is anteverted and anteflexed
Angle of anteversion is 90°
Angle of anteflexion is 120°
The organ is pear shaped and in nonpregnant women measures approximately 8 cm in length and weighs 30 to 100 gm
The fallopian tubes and the cervical canal communicate with the uterine cavity, which is lined by the endometrium
The uterine fundus is covered by peritoneum except in the lower anterior portion, where the bladder is contiguous with the lower uterine segment and the peritoneum is reflected, and laterally where the folds of the broad ligament are attached. The uterus is supported by condensations of endopelvic fascia and fibromuscular tissue laterally at the base of the broad ligaments

Blood supply of uterus is by uterine artery which is tortuous and branch of anterior division of internal iliac artery lying on the lateral aspect of uterus in the broad ligament.

Occurs when the uterus and its adjoining structures herniate through the vaginal canal
Prolapse is described as first, second, or third degree in severity, the last being protrusion of the entire uterus from the vagina, with the entire vagina everted as a consequence.
Although congenital weakness of the supporting tissues may occasionally cause uterine prolapse, the most frequent cause is childbirth. The signs of uterine prolapse are protrusion of the cervix or uterus through the introitus. Prolapse is frequently associated with cystocele or rectocele, and these defects may cause presenting symptoms. Symptoms include backache, significant pelvic pressure, and ulceration or bleeding of the prolapsed structures.

Tortous ducts about 10 cms in length:

Arise from the superior portion of the lateral borders of the uterus, superior to the attachment of the round ligaments, and are patent. The distal ends, the fimbriae, open into the abdominal cavity and the proximal ends open into the uterine cavity. It is divided into interstitial, isthmic, ampullar, and fimbriated portions
The wall is thin with two muscular layers and an outer layer of peritoneum within the upper borders of the broad ligament.

Lie in the ovarian fossa. Ovaries are almond-shaped structure measuring 2 × 3 × 3 cm and is located on the posterior surface of the broad ligament and inferior to the fallopian tube. The ovary has a cortex and a medulla. Germinal epithelium, a single layer of cuboidal cells, covers condensed fibrous tissue called the tunica albuginea. Follicles originate within the ovarian cortex and are composed of the basic embryonic complement; no new follicles are formed after birth

Mesovarium is a fold of peritoneum by which ovary is connected to the broad ligament

The Arterial blood supply is predominantly by ovarian artery a branch of Abdominal aorta

Venous drainage is by Pampiniform plexus. The left ovarian vein empties into the left renal vein; the right ovarian vein empties into the vena cava just inferior to the renal vein.

It is approximately 4 cm in length
Extends between the internal (deep inguinal) ring and the external (superficial inguinal) ring opening
The inguinal canal contains either the spermatic cord or the round ligament of the uterus
The inguinal canal is bounded superficially by the external oblique aponeurosis
The superior wall is composed of internal oblique muscle, transversus abdominis muscle, and the aponeuroses of these muscles
The inferior wall of the inguinal canal is formed by the inguinal ligament and lacunar ligament
The posterior wall (floor) of the inguinal canal is formed by the transversalis fascia and the aponeurosis of the transversus abdominis muscle
Hesselbach’s triangle: The inferior epigastric vessels serve as the superolateral border of Hesselbach’s triangle. The medial border of the triangle is formed by the rectus sheath, and the inguinal ligament serves as its inferior border
Hernias occurring within Hesselbach’s triangle are considered direct hernias, whereas hernias occurring lateral to the triangle are indirect hernias.

The SCALP has five layers:

S – Skin
C – Connective tissue
59A – Aponeurosis -galea aponeurotica
L – Loose connective tissue
P – Pericranium

The scalp receives a rich vascular supply. This arises from both the external and internal carotid arteries with the vessels lying in the dense connective tissue layer.

The anterior part of the scalp is supplied by the supratrochlear and supraorbital arteries, and branches of the internal carotid via the ophthalmic artery

The lateral and posterior part of the scalp is supplied by the superficial temporal, posterior auricular and occipital arteries, and branches of the external carotid

The sensory nerves run with the arteries and are derived from the trigeminal nerve at the front and sides

The posterior aspect is supplied by the greater and lesser occipital nerves with motor supply to the occipitofrontalis muscle by the facial nerve

Venous drainage of the face and anterior scalp is via the facial vein. The lateral and posterior aspects are drained by the external jugular vein and the vertebral venous plexus, respectively. The veins of the scalp and face communicate directly with the intracranial venous sinuses via emissary veins, hence infections in the nasal region have the potential to cause cavernous sinus thrombosis

Lymph drainage from the scalp is to the preauricular and occipital lymph nodes

The loose areolar tissue under the galea aponeurotica is a ‘Dangerous zone for infections‘. Pus can spread freely in this layer and reach the intracranial sinuses through the emissary veins

Abscesses and hematomas under the pericranium are limited to the area of one bone because the pericranium is firmly adherent to the sutures between the skull bones

Osteomyelitis of the skull is associated with a subperiosteal swelling and edema of the scalp referred to as Port’s puffy tumor

The Le Fort I fracture separates the alveolus and palate from the facial skeleton above

The fracture line runs through points of weakness from the pyriform aperture, through the lateral and medial wall of the maxillary sinus running posteriorly to include the lower part of the pterygoid plates

The Le Fort II fracture is pyramidal in shape. The fracture involves the orbit, running through the bridge of the nose, and the ethmoids whose cribriform plate maybe fractured, leading to a dural tear and CSF leak. It continues to the medial part of the infraorbital rim, through the infraorbital foramen and through the infraorbital fissure. The orbital floor is always involved

The Le Fort III fracture effectively separates the facial skeleton from the base of the skull — The fracture lines run high through the nasal bridge, septum and ethmoids, again with the potential for dural tear and CSF leak, and irregularly through the bones of the orbit to the frontozygomatic suture. The zygomatic arch fractures, and the facial skeleton is separated from the bones above at a high level through the lateral wall of the maxillary sinus and the pterygoid plates.

Motor area
Premotor area
Brocas area
Sensory area
Visual area
Werneckies area

Precentral gyrus
Anterior to motor area
Motor speech area (Inferior frontal gyrus)
Postcentral gyrus
Occipital lobe
Superior temporal lobe

Frontal lobe	Precentral cortex (Post Part)	Primary motor area	Area 4 – center for movement
		(concerned with initiation of voluntary movements and speech)	Area 4S – suppressor area. Inhibits movements initiated by area 4.
		Premotor area	Area 6 – concerned with coordination of movements initiated by area 4.
			Area 8 – frontal eye field.
			Area 44 and 45 (broca’s area) – motor area for speech.
		Supplementary motor area	Concerned with coordinated skilled movements.
	Prefrontal cortex (Ant Part)	Silent area or association area Center for higher functions – emotion, learning, memory	Area – 9 to 14, 23, 24, 29 and 32. Center for planned action Seat of intelligence. Personality of individual
			Area 1 – concerned with sensory perception
Parizetal lobe	Somesthetic area I		Area 2 and 3 – integration of these sensations. Spatial recognition. Recognition of intensity, similarities and diff. B/W stimuli
	Somesthetic area II		Concerned with perception of sensation.
	Somesthetic association area		Synthesis of various sensations perceived by S. Area-I. Stereognosis
Temporal lobe	Primary auditory area		Area 41, 42 and wernicke’s area – concerned with perception of auditory impulses, analysis of pitch, determination of intensity and source of sound Superior part of temporal gyrus.
	Auditopsychic area		Area 22 – Interpretation of auditory sensation
	Area of equilibrium		Maintenance of equilibrium
Occipital lobe	Primary visual area		Area 17 – Perception of visual impulse Lines of Gernari seen.
	Visual association area		Area 18 - Interpretation of visual impulses
	Occipital eye field		Area 19 - Movements of eye

Lemniscus, tract and sensation	Thalamic nucleus	Part of the internal capsule	Sensory areas of the cerebral cortex
Medial lemniscus (Proprioception and fine touch)	PLVNT	SENSORY RADIATION	Upper 1/3 of sensory area in post-central gyrus (Arm and leg region).
Spinal lemniscus (Pain, temperature and crude touch)
Trigeminal lemniscus (Pain, temperature, touch and proprioception from the «head», taste)	PMVNT	In posterior ½ of postlimb of internal capsule (IC)	Lower 1/3 of sensory area in post-central gyrus (Face region).
Lateral lemniscus (hearing)	Medial geniculate body [MGB]	AUDITORY RADIATION in sublentiform part of IC	Auditory area in Heschl’s gyrus in temporal lobe (area 41 and 42).

Part of internal capsule	Types of fibers in it
Anterior limb	Fibers from and to the prefrontal area of the cortex
Genu (MOTOR)	Corticobulbar fibers Sensory fibers from thalamus to brain
Ant ½ of posterior limb (MOTOR)	Corticospinal fibers
Post ½ of posterior limb (SENSORY)	SENSORY radiation (From PLVNT and PMVNT to main sensory area in post central gyrus)
Retrolentiform part (VISION)	OPTIC radiation (From LGB to visual sensory area 17)
Sublentiform part (HEARING)	AUDITORY radiation (From MGB to auditory area in temporal lobe)

61Remember: M-M (medial geniculate body/hearing (music)

Lateral L-L Lateral geniculate body/light)

A small lesion at the level of internal capsule can result in a clinical scenario with widespread manifestations and most of them lethal depending on what part of internal capsule is damaged.

The internal capsule maybe damaged by a cerebrovascular lesion mostly by Hemorrhage (rupture of Charcots artery) leading to Hemiplegia on the opposite side of the body.

In this type of Hemiplegia motor functions are effected mostly and sensory functions later or not at all because motor fibers lie laterally and the arterial supply is more laterally as a result of which are motor fibers likely to be effected more.

On the «same» side of the lesion

Pyramidal tract damage results in: UMNL and motor paralysis below the injury (spastic paralysis, hyperactive reflexes, loss of superficial reflexes and Babinski sign)
Proprioceptive tracts damage (gracile and cuneate) results in: loss of sense of position, sense of passive movement, sense of vibration and touch discrimination below the injury. These are the signs of sensory ataxia.

On the «opposite» side of the lesion:

Lateral spinothalamic tract damage results in: loss of pain and temperature sensation beginning one or two dermatomes below the lesion
Ventral spinothalamic tract damage results in: little or No change in the sense of simple touch.

Midbrain: Usually the fibers of the third (oculomotor) nerve are affected — alternating oculomotor hemiplegia, this means;

Hemiplegia on opposite half of the body (UMNL)

Signs of oculomotor nerve paralysis on the same side (LMNL)

Pons: Usually the fibers of the sixth (abducent) nerve are affected — alternating abducent hemiplegia, this means:

Hemiplegia on opposite half of the body (UMNL)

Signs of abducent nerve paralysis on the same side (LMN)

Medulla: Usually the fibers of the hypoglossal nerve are affected — alternating hypoglossal hemiplegia, this means

Hemiplegia on opposite half of the body (UMNL)

Signs of hypoglossal nerve paralysis on the same side (LMNL)

Left middle cerebral artery: Blockage of this vessel would cause, among other effects, right-sided hemiplegia and sensory deficits mainly of the face and arms, a right visual field defect with inability to gaze to the right, and aphasia.
63Right middle cerebral artery: Blockage of this vessel would cause, among other things, left-sided hemiplegia and sensory deficits mainly of the face and arms and left visual field neglect with inability to gaze to the left. In addition, there maybe neglect of the left side.
Left anterior cerebral artery: This vessel supplies the medial aspects of the left hemisphere. Blockage may cause a weak, numb right leg (and possibly arm symptoms in milder forms). The face is typically spared.
Right anterior cerebral artery: This vessel supplies the medial aspects of the right hemisphere. Blockage may cause a weak, numb left leg (and possibly arm symptoms in milder forms). The face is typically spared.
Left posterior cerebral artery: This lesion presents as a right-sided visual field deficit, alexia without agraphia (if the corpus callosum is spared), and possible defects in naming colors.
Right posterior cerebral artery: This lesion typically presents as a left-sided visual field deficit along with left-sided sensory loss if the thalamus is affected. There may also be left-sided neglect
Visual cortex is supplied by posterior + middle cerebral artery.
Left posterior inferior cerebellar artery: This lesion would cause infarction of the lateral medulla and inferior cerebellar surface, causing vertigo with vomiting, dysphagia, and dysarthria. In addition, there would be nystagmus looking toward the left, left–sided Horner’s syndrome, and loss of pinprick sensation on the left side of the face and on the right side of the trunk and extremities. This condition is also known as Wallenberg’s syndrome.

Right posterior inferior cerebellar artery: This lesion would cause infarction of the lateral medulla and inferior cerebellar surface, causing vertigo with vomiting, dysphagia, and dysarthria. In addition, there would be nystagmus looking toward the right, right–sided Horner’s syndrome, and loss of pinprick sensation on the right side of the face and on the left side of the trunk and extremities. This condition is also known as Wallenberg’s syndrome.

Optic nerve is not only a cranial nerve. It is a tract and direct extension of CNS
This nerve is about 4 cm long
The optic nerve is enclosed in 3 sheaths covering with meninges
It is crossed by ophthalmic artery
- Trigeminal nerve is the largest cranial nerve
- Abducent nerve has the longest course
- Trochlear nerve has the longest intracranial course. Thinnest as well
- Cranial nerve 3 and 4 have their nuclei in midbrain
- Cranial nerve 5, 6, 7, 8 have their nuclei in pons
- Cranial nerve 9, 10, 11, 12 have their nuclei in medulla
Cranial nerve emerging from dorsal aspect of brain: Trochlear
MC nerve involved in intracranial aneurysms: Occulomotor
Common nucleus for VII, IX, X nerves is Nucleus Tractus Solitarius. (NTS)
Trochlear nerve has the longest intracranial course

No.	Nerve	Type	Function
1.	Olfactory	Sensory	smell
2.	Optic	Sensory	vision
3.	Oculomotor	Motor	To all muscles of the eye except two: (superior oblique and lateral rectus)
4.	Trochlear	Motor	To one eye muscle (superior oblique)
5.	Trigeminal	Mixed mainly sensory with small motor part	Sensory to Mouth Face Ant ½ of scalp
6.	Abducent	Motor	To one eye muscle (lateral rectus)
7.	Facial	Mixed Motor ———Sensory Parasympathetic	Motor to muscles of the face Sensory: taste to anterior 2/3 of tongue Parasym Pathetic to certain glands.
8.	Vestibulocochlear	Sensory	Hearing (cochlear part) Equilibrium (Vestibular part)
9.	Glossopharyngeal	Mixed Motor ———Sensory Parasympathetic	Sensory for pharynx and tongue Motor to: One muscle of pharynx (stylophar ngeus) Parasympathetic to parotid gland
10.	Vagus (Including Cranial accessory)	Mixed Motor ———Sensory Parasympathetic	Motor to: Muscles of pharynx, larynx and palate Parasympathetic and sensory to: The structures in the thorax and abdomen
11.	Spinal Accessory	Motor	To two important muscles of the neck: Sternomastoid Trapezius
12	Hypoglossal	Motor	To all muscles of the tongue (except one)

The chief function of the 1st cranial nerve (olfactory nerve) is concerned with the sense of smell. Cells of origin are located in the nasal mucosa. Nerve filaments group and pass through the cranium at cribriform plate and end in olfactory bulb. The olfactory nerve is composed exclusively of somatic afferent fibers.

The olfactory nerve branches penetrate through the cribriform plate, and collect in the olfactory bulb and nerve which passes under the frontal lobe to the temporal lobe and other centers

EXAMINATION

Each nostril is examined separately. One nostril is closed while the patient sniffs with the other. Mild aromatic substances such as orange, coffee, or tobacco should be used as strong irritant smells stimulate the sensory endings of the fifth nerve. The result of affection will be loss of smell or anosmia.

It supplies all extraocular muscles except the superior oblique and the lateral rectus

Complete paralysis results in:

External ophthalmoplegia: In a complete lesion inability to move the eye upward, inward and downward
External Squint: The eye is deviated laterally and downwards due to the unopposed action of the lateral rectus and superior oblique
Diplopia: A person sees double
Ptosis: Drooping of the upper eyelids due to paralysis of levator palpabrea superioris
Dilated nonreactive pupil due to paralysis of the sphincter pupillae. The pupil also shows no reaction to light (direct or consensual), or to accommodation.

There is weakness or paralysis of the superior oblique muscle which normally moves the eye downwards and inwards
Result: Defective depression of the adducted eye. The patient is unable to look at his shoulder
Symptom presentation: DIPLOPIA (double vision), when looking downwards, e.g. when reading or descending the stairs. The head may tilt to the opposite side to minimize the diplopia.

The sixth nerve supplies the lateral rectus which normally rotates the eye laterally. Its paralysis causes:

Internal Squint: The eyeball is turned inwards due to unopposed adduction of the medial rectus
Diplopia, which is maximum on looking outwards.

The sensory fibers are divided into three divisions:

Ophthalmic Division
Maxillary Division
Mandibular Division

Sensation

Sensation is tested in the distribution of the 3 divisions of the nerve. Routinely, it is sufficient to test the sensation at three Sites: on the forehead, the cheek and over the lower jaw, together with anterior two-thirds of the tongue

Motor Functions

A. Masseters And Temporalis:

Any wasting of the temporalis
The degree of contraction of the temporalis and masseter by palpation while asking the patient to bite hard.

Weakness in the facial muscles may result from:

Upper motor neuron lesion:

Here only the muscles of the lower part of face are affected. The eye closure is normal

This is because the muscles of the lower part (unlike those of the lower part) are activated through the upper motor neuron fibers of both sides

Spontaneous emotional expression is unaffected

Lower motor neuron lesion:

All the muscles of the face (upper and lower) are affected on the same side

Facial nerve passes through parotid gland but does not supply it

Facial nerve supplies submandibular and lacrimal glands

Arterial supply to facial nerve: ascending pharyngeal artery.

Facial Nerve has:

The longest intraosseous course
It is the Mc paralyzed cranial nerve

Muscles supplied by facial nerve:

Platysma
Stylohyoid
Muscles of facial expression
Buccinator
Stapedius
Posterior belly of digastric
Submandibular, Lacrimal, nasal gland
Supplies gustatory sensation to soft palate
Kindly never forget that despite the fact that facial nerve traverses the substance of parotid but does not supply it. (keeps it high and dry)

Facial nerve is related to

Pterygopalatine ganglion
Geniculate ganglion submandibular ganglion

Submandibular

The eighth nerve consists of two parts which have different functions Cochlear and vestibular nerves

The cochlear part is concerned with hearing. An affection results is tinnitus and deafness
The vestibular part is concerned with equilibrium. Its affection may result in vertigo.

Paralysis of Glossopharyngeal nerve causes:

Anesthesia of the pharynx
Loss of taste on the posterior third of the tongue

Glossopharyngeal nerve is involved in:

Jugular foramen syndrome: Involving IX, X, XI cranial nerves
Collet Sicard Syndrome: Involving IX, X, XI, XII cranial nerves (Extracranially)
Villaret Synrome: Lesion in retropharyngeal space involving IX, X, XI, XII cranial nerves

Paralysis of vagus nerve causes:

Ipsilateral paralysis of the palate,

Ipsilateral paralysis of the pharynx and

Ipsilateral paralysis of the larynx with anesthesia of the larynx on the affected side

Remember: The Recurrent Laryngeal nerve arises from vagus. On the Right side it winds around the subclavian artery and on the Left side it winds around the aortic arch behind ligamentum arteriosum.

As a Result of damage to the Accessory nerve

Sternomastoids

Unilateral

Apparent wasting

The muscle does not stand out on testing

Bilateral

Wasting of the neck which appears like that of a chicken

Falling of head backwards

Trapezius

Unilateral paralysis

Drooping of the shoulder when arm is hanging
Weak movements on testing

Supplies all palatal muscles except Tensor palate

Spasmodic torticollis is due to central irritation of this nerve (cranial part)

Lesion of one hypoglossal nerve results in deviation of the tongue ‘towards the paralyzed side’. If you ask the patient to protrude his tongue the muscles of the same side of the lesion become paralyzed and begin to atrophy (lower motor neuron lesion)
Safety muscle of tongue is geniglossus supplied by hypoglossal nerve.

Also known as Hypophysis cerebri. Pineal is Epiphysis cerebri

The average adult pituitary measures 11 × 15 × 5 mm

The gland is oval, bilaterally symmetrical, and brownish red

The pituitary is approximately 20% larger in females than in males and it enlarges about in females during pregnancy

It lies within the sella turcica (Turkish saddle)

This fossa is bordered anteriorly, posteriorly, and inferiorly by the sphenoid bone and laterally by the cavernous sinus

The floor of the sella forms the roof of the sphenoidal sinus

The diaphragma sellae, a thick reflection of dura mater, covers the roof of the sella and closely encircles the pituitary stalk in 50% of individuals

The arterial supply to the hypothalamic-pituitary region is complex and arises from three sources

The inferior hypophyseal artery, a branch of the carotid artery, supplies the posterior pituitary.
The superior hypophyseal arteries branch from the circle of Willis to supply the median eminence
The middle hypophyseal arteries are of variable origin and supply the pituitary stalk

Capillary portions of the superior hypophyseal arteries drain from the hypothalamus, the median eminence, and the superior portions of the pituitary stalk. These vessels drain into the hypophyseal portal system, which forms a secondary venous plexus in the anterior pituitary and ultimately empties into the cavernous sinus. This portal venous system constitutes the principal blood supply to the anterior pituitary and serves as the medium through which releasing hormones from the hypothalamus reach the pituitary.

68The pituitary has dual embryonic origin

The Anterior pituitary arises from embryonic ectoderm (Rathke’s pouch) and includes the pars distalis, pars intermedia (vestigial in humans), and pars tuberalis

The Posterior pituitary of the gland arises from the diencephalon and includes the neural stalk, infundibulum, and posterior lobe

Embryonic defects in invagination and obliteration of the pharyngeal extent of Rathke’s pouch may lead to craniopharyngiomas or hormonally active ectopic pituitary adenomas.

Paralysis of 3, 4, 6 cranial nerves indicates lesion of cavernous sinus
Occulomotor, trochlear and ophthalmic nerves lie in lateral wall of cavernous sinus
Abducent nerve is a direct content of cavernous sinus
Infections from dangerous area of face can spread to cavernous sinus

The pituitary gland is located in the pituitary fossa within the skull. The floor of this fossa is formed by the sella turcica. The lateral walls of the fossa are formed by the cavernous sinuses. The abducens nerve passes through the cavernous sinus along with the internal carotid artery. As the tumor expands laterally, the first nerve that will be encountered is the abducens nerve, producing lateral rectus palsy.

Organ	Sympathetic	Parasympathetic
Pupil	Dilates	Constricts
Lacrimal and salivary glands	Stops secretion	Produces secretion
Heart	Accelerates	Slows
Bronchioles	Dilates	Constricts
Alimentary canal	Dilates	Contracts
Urinary bladder	Dilates	Contracts
Penis		Causes erection [For this reason the pelvic nerve was called the nervus erigens].

Subcallosal Gyri
Cingulate Gyri
Hippocampal formation comprising of Hippocampal Gyrus, Parahippocampal Gyrus and Dentate gyrus
Amygdaloidal nucleus
Mammillary bodies
Anterior thalamic nucleus

Feeding
Flight
Feeling
Fighting and
Fun {sex}

Foramen	Contents
Optic canal	Optic (II) Nerve and ophthalmic artery
Superior orbital fissure	III, IV, VI and ophthalmic division of V cranial nerves, sympathetic nerves and ophthalmic veins
Stylomastoid foramen	VII cranial nerve
Foramen Rotundum	Maxillary division of V
Foramen ovale	Mandibular division of V and accessory meningeal artery
Foramen spinosum	Middle meningeal artery, meningeal branch of the mandibular nerve
Foramen magnum	Accessory (XI) nerve, vertebral and spinal arteries. NOT SPINAL CORD
Foramen lacerum	Internal carotid artery, lesser petrosal Nerve (branch of IX), greater petrosal Nerve (branch of VII), deep petrosal
Jugular foramen	Inferior petrosal sinus (anterior part) Internal jugular vein and IX, X, XI cranial nerves
Hypoglossal foramen	XII cranial nerve, meningeal branch of ascending pharyngeal artery
Internal auditory meatus	VII and VIII cranial nerves, labyrinthine (internal auditory) artery
Dorello’s canal	Abducent nerve.

Clear fluid
Colorless fluid
Choroid Plexus (formed by)
Chloride content ↑
Cells minimal
Cushions the brain
Circulus arteriosus (branches) supply choroids plexus
CSF is principally secreted by choroid plexus
Choroid plexus is absent in anterior horn of lateral ventricle
Total volume of CSF 150 ml
Normal adult CSF pressure: 6 —12 mm Hg
pH of CSF is: 7.33
Epidural space is devoid of CSF
Rate of CSF absorption is the main factor controlling CSF Pressure
Persistent leakage can cause headache
No neutrophils in normal state seen

* Occlusion of the vertebral artery may cause Medial Medullary Syndrome which is characterized by:

Paralysis or atrophy of tongue on the side of lesion (XII nerve involvement)
Paralysis of arm and leg on opposite side
Impaired tactile and proprioceptive sense on opposite side. (Involvement of pyramidal tract and medial lemniscus)

70* The posterior inferior cerebellar artery:

It is the largest and main branch of the vertebral artery
It has a tortuous S-shaped course. Immediately after it arises from the vertebral artery, it runs backwards around the lower end of the olive passing through the rootless of the hypoglossal nerve, it then turns round the inferior cerebellar peduncle and finally divides into two terminal branches which supply: (a) the inferior vermis (b) the posterior part of the inferior surface of the cerebellum.

Impaired pain and temperature sense on opposite side
- Nystagmus (involvement of vestibular nucleus)
- Dysphagia (involvement of nucleus ambigus)
- Nystagmus (involvement of cerebellum)
- Horner’s syndrome (involvement of sympathetic pathway)

Loss of motor function below the level of the lesion (due to damage to the corticospinal tracts)
Loss of pain and temperature Sensation below the level of the lesion (due to damage to the spinothalamic tracts)
Weakness of limbs (due to damage of the anterior grey horns in the cervical or lumbar regions of the cord)
Loss of bowel and bladder control (due to damage of the descending autonomic tracts)

Loss of position sense, vibration sense and light touch due to damage of the posterior white columns

Larynx has three paired and three unpaired cartilages

Extends from C3-C6

Anatomic basis of stridor is in larynx

The larynx serves as the sounding source for speech. A fundamental tone is produced by the movement of the vocal cords, which is brought about by the flow of exhaled air past lightly approximated vocal cords

The internal laryngeal nerve is sensory to larynx above vocal cords
The recurrent laryngeal nerve is sensory to larynx below vocal cords
All muscles of larynx except cricothyroid are supplied by recurrent laryngeal nerve
Cricothyroid supplied by External laryngeal nerve

Abductor of vocal cords: Posterior Cricoarytenoid

Adductor of vocal cords:

Lateral cricoarytenoid
Transverse arytenoids
Cricothyroid
Thyroarytenoid

Tensor of vocal cords: Cricothyroid

Relaxor of vocal cords:

Thyroarytenoids
Vocalis

Depression: Lateral Pterygoid
Elevation: Temporalis, Massetter, Medial Pterygoid
Protrusion: Pterygoids
Retraction: Posterior fibers of Temporalis
Lateral movements: Pterygoids
Buccinator: Nota muscle of mastication

The backward movement step is accomplished by the posterior fibers of the temporalis muscle
The digastric helps to depress the lower jaw during chewing
The lateral pterygoid helps to move the lower jaw forward during chewing
The medial pterygoid helps to elevate the lower jaw during chewing
The mylohyoid helps to depress the lower jaw during chewing

Ansa cervicalis is a thin nerve loop that lies in the anterior wall of carotid sheath

Superior root is a continuation of descending branch of hypoglossal (XII) Cranial nerve. Superior root supplies Superior belly of omohyoid. Its fibers are derived from first cervical nerve

Inferior root is derived from spinal nerves C2 and C3

Loop of Ansa supplies:

Inferior belly of omohyoid
Sternothyroid
Sternohyoid

Dangerous area of face: Lowerpart of nose and upper lip
Dangerous area of scalp: Loose areolar tissue layer of scalp
Dangerous zone of eye: Ciliary body

Commonest site of BHP: Periurethral zone
Commonest site of cancer prostate: peripheral zone
Commonest site of varicocele: Left side
Commonest position of appendix: Retrocecal
Commonest site of internal hemorrhoids: 3, 7 and 11 O’clock

Reflex	Stimulus	Response	Center – spinal segment involved
Scapular	Irritation of skin at the interscapular space	Contraction of scapular muscles and drawing in of scapula	C5 to T1
Upper abdominal	Stroking the abdominal wall below the costal margin	Ipsilateral contraction of abdominal muscle and movement of umbilicus towards the site of stroke	T6 to T9
Lower abdominal	Stroking the abdominal wall at umbilical and iliac level	Ipsilateral contraction of abdominal muscle and movement of umbilicus towards the site of stroke	T10 to T12
Cremasteric	Stroking the skin at upper and inner aspect of thigh	Elevation of testicles	L1, L2
Gluteal	Stroking the skin over glutei	Contraction of glutei	L4 to S1, S2
Plantar	Stroking the sole	Plantar flexion and adduction of toes	L5 to S2
Bulbocavernous	Stroking the dorsum of glans penis	Contraction of bulbocavernous	S3, S4
Anal	Stroking the perianal region	Contraction of anal sphincter	S4, S5

Emotion
Memory
Higher functions
- Consolidation of long-term memory occurs in hippocampus
- Processing of short term memory to long term occurs in hippocampus
- Amygdala is the window of limbic system
- Damage to amygdala causes Kluver Bluck syndrome
- Reward center is in medial forebrain bundle.

Uncal or transtentorial herniation. The herniated uncus will compress the oculomotor nerve, the posterior cerebral artery, and the brainstem. The pathophysiologic consequences include oculomotor paralysis (manifesting with fixed and dilated pupil on the same side), ipsilateral infarction of the occipital lobe, and hemorrhages within the midbrain and pons. The latter may result in respiratory paralysis and death
Cerebellar tonsillar herniation refers to downward displacement of the cerebellar tonsils through the foramen of magnum. This results from space-occupying lesions in the infratentorial compartment, such as bleeding and tumors. It leads to compression of the medulla and death by cardiorespiratory arrest
Subfalcine (cingulate) herniation describes the lateral displacement of the cingulate gyrus beneath the falx cerebri. This event is caused by space-occupying masses in the cerebral hemisphere. It leads to compression of the anterior cerebral artery and infarction of dependent cerebral territories (mostly the medial portion of the frontal and parietal lobes)
Reverse cerebellar herniation is a rare form of herniation due to midbrain lesions (again, hemorrhages and tumors) that push the midbrain upward through the incisura of the tentorium
Transcalvarial herniation may develop in open (i.e. accompanied by calvarial bone fractures) head injuries if brain parenchyma is displaced outside the cranial cavity through a calvarial defect
Split brain syndrome: Disconnection syndrome of cerebral cortex resulting from transection or congenital absence of cerebral cortex.

Association fibers: Connecting different areas of same cerebral hemisphere

Superior longitudinal fasiculus
Inferior longitudinal fasiculus
Cingulum
Uncinate fasiculus

73Projection fibers: Connecting cerebral cortex to other parts of CNS

Corticospinal tract
Internal capsule

Commisural fibers: connecting corresponding parts of two cerebral hemispheres

Corpus callosum
Anterior commisure
Posterior commisure
Hippocampal commisure
Habenular commisure
Hypothalmic commisure

	Effects	Upper motor neuron	Lower motor neuron lesion
Clinical observation	Muscle tone	Hypertonic	Hypotonic
	Paralysis	Spastic type of paralysis	Flaccid type of paralysis
	Wastage of muscle	No wastage	Present
	Superficial reflexes	Lost	Lost
	Plantar reflex	Abnormal – babinski’s sign	Absent
	Deep reflexes	Exaggerated	Lost
	Clonus	Present	Lost

The ‘Extroter’ of Eye ball is Inferior Oblique and Inferior Rectus
The ‘Introter’ of Eye ball is Superior Oblique and Superior Rectus.
Action of Superior oblique is Abduction, Intorsion and depression
Dilator Pupillae dilates pupil and is supplied by Sympathetics
Sphincter Pupillae constricts pupil and is supplied by Parasympathetics
- LR₆S0₄
- Lateral rectus is supplied by 6th Cranial Nerve (Abducent)
- Superior oblique is supplied by 4th Cranial Nerve (Trochlear)
- Rest other ocular muscles are supplied by 3rd Cranial Nerve (Occulomotor)
- Muscle attached to posterior tarsal margin: Mullers muscle
- Ligament of Lockwood is found in Orbit.

Live Free To See No Insult at All

Lacrimal Nerve
Frontal Nerve
Trochlear Nerve
Superior Ophthalmic Vein
Nasociliary Nerve
Inferior Ophthlamic Vein
Abducent Nerve

Maxillary nerve
Zygomatic nerve
Infraorbital vessels
Orbital branch of pterygoplatine ganglion

Central scotoma ~ macula
Ipsilateral blindness ~ optic nerve
Bitemporal hemianopia ~ optic chiasm
Homonymous hemianopia ~ optic tract
Upper homonymous quadrantanopia ~ temporal optic radiations
Lower homonymous quadrantanopia ~ parietal optic radiations
Also, cortical lesions produce defects similar to those of the optic radiations, but may spare the macula.

Spinal cord in adults ends at L1- L2
Spinal cord in infant sends at L3
Thoracic and sacral curves are concave anteriorly
Subarachnoid space/Subdural space ends at S2
Dural sheath ends at S2
Filum terminale and piamater extend up to tip of coccyx
Number of spinal nerve pairs: 31.

It is a serious neurologic condition in which there is acute loss of function of the lumbar plexus, neurologic elements (nerve roots) of the spinal canal below the conus of the spinal cord

After the conus, the canal contains a mass of nerves (the cauda equina or ‘horse-tail’) that branches off the lower end of the spinal cord and contains the nerve roots from L1-5 and S1-5. The nerve roots from L4-S4 join in the sacral plexus which affects the sciatic nerve, which travels caudally (toward the feet)

Cervical region	C1-C7 Add1
Upper Thoracic Lesion	T1 –T6 Add 2
Lower Thoracic Lesion	T7-T9 Add 3
T 10	Corresponds to L1-L2
T12-L1	Corresponds to L5-S1

Situation	Tract	Function
Anterior white funiculus	Anterior spinothalamic tract	‘Crude‘ touch sensation
	Lateral spinothalamic tract	Pain and temperature sensation
	Ventral spinocerebellar tract	Subconscious kinesthetic sensations
	Dorsal spinocerebellar tract	Subconscious kinesthetic sensations
Lateral white funiculus	Spinotectal tract	Concerned with spinovisual reflex
	Fasiculus dorsolateralis	Pain and temperature sensations
	Spinoreticular tract	Conciousness and awareness
	Spino olivary tract	Proprioception
	Spinovestibular tract	Proprioception
	Fasciculus gracilis	Tactile sensation
Posterior white funiculus	Fasciculus cuneatus	Tactile localization
		Tactile discrimination
		‘Vibratory’ sensation
		‘Conscious kinesthetic sensation’
		‘Stereognosis’

Situation	Tract	Function
Pyramidal tracts	Anterior corticospinal tract	Control voluntary, skilled movements
Pyramidal tracts	Lateral corticospinal tract	Forms upper motor neurons
Extra Pyramidal tracts	Medial longitudinal fasciculus	Coordination of reflex ocular movement Integration of movements of eyes and neck
	Anterior vestibulospinal tract	Maintenance of muscle tone and posture Maintenance of position of head and body during acceleration
	Lateral vestibulospinal tract
	Reticulospinal tract	Coordination of voluntary and reflex movements Control of muscle tone Control of respiration and blood vessels
	Tectospinal tract	Control of movement of head in response to visual and auditory impulses
	Rubrospinal tract	Facilitatory influence on flexor muscle tone
	Olivospinal tract	Control of movements due to proprioception

Hand E Stain (Hematoxylin and Eosin): Hematoxylin, a natural dye product, acts as a basic dye that stains blue or black. Nuclear heterochromatin stains blue and the cytoplasm of cells rich in ribonucleoprotein also stains blue
The aniline dye, Eosin, is an acid dye that stains cytoplasm, muscle, and connective tissues various shades of pink and orange. This difference in staining intensity is useful in differentiating one tissue from another
Vital Stain: Such as Neutral red, Trypan blue are used for staining living cells such as Reticuloendothelial cells
Metachromatic Stains are used for staining mast cells with Toluidine blue. The stains react with granules of mast cells (metachromasia) to give a new color to the cells
Periodic Acid-Schiff Method (PAS): Principally used to demonstrate structures rich in carbohydrate macromolecules such as glycogen, glycoprotein, and proteoglycans found in ground substance of connective tissues, basement membranes and mucus
Phosphotungstic Acid Hematoxylin (PTAH): This is an ideal stain for the demonstration of striated muscle fibers and mitochondria, which stain blue
Silver Stains: Certain tissue components called Argyrophilic have a natural affinity for silver salts. Reticular fibers and the granules in diffuse endocrine cells are argyrophilic
Sudan Stains: Sudan dyes are used to stain lipids. The Sudan dyes, e.g. Sudan IV, dissolve in droplets containing triglycerides and color them intensely.

Umbilical arteries carry venous blood
Pulmonary vasculature also follows reverse pattern
Coronary arteries have three elastic lamina: Internal, middle and external
Umbilical arteries have no elastic lamina
The arteries of lower limb have more developed muscular tissue than those of upperlimb

Scaphocephaly	Boat shaped skull due to premature union of saggital suture
Acrocephaly/Oxycephaly	Pointed skull due to premature union of coronal suture
Plagiocephaly	Twisted skull due to assymetrical union of sutures
Trigonocephaly	Triangular prominence of forehead due to premature fusion of metopic suture
Brachycephaly	Short and broad skull
	Seen in Cleidocranial dysostosis
	Seen in Downs Syndrome
	Seen in Achondroplasia
Dolicocephaly	Long and thin skull
	Seen in Marfans syndrome
Anencephaly	Vault of skull not developed resulting in the absence of a major portion of the brain, skull, and scalp

Contain air spaces. Usually present in skull
Make the skull light in weight
Act as air conditioners
- Maxilla
- Sphenoid
- Ethmoid
- Mastoid Bones

Patella
Pisiform
Fabella

Lower end of femur
Upper end of tibia
Calcaneum

Anti rape muscle/muscle virgineous: Gracilis
Cheating muscle: Superior oblique of eye
Safety muscle of tongue: Genioglossus
Tailors muscle: Sartorius
Thermostat of testis cremaster
Bladder muscles in whorls detrusor

Adductor magnus
Biceps Femoris
Pectineus
Digastric
Flexor digitorum superficialis

Digastric: Anterior belly, posterior belly
Omohyoid: Superior belly, inferior belly
Occipitofrontalis: Occipital belly, frontal belly
Gastrocnemius: Lateral head, medial head
Ligament of Treitz: Skeletal part, smooth part

Glans Penis and clitoris	Cloquets node
Rest of Penis	Superficial inguinal node
Labium majus	Superficial inguinal node
Testis	Preaortic/Para aortic nodes
Ovaries	Preaortic/Para aortic nodes
Palatine tonsil	Jugulo digastric nodes
Tip of Tongue	Submental nodes
Anal canal above pectinate line	Internal iliac nodes
Anal canal below pectinate line	Superficial inguinal nodes
Delphic nodes	Pretracheal
Spongiform urethra	Deep inguinal nodes

78Lymph node of lund: cystic lymph node of gallbladder
Cloquets node/Rossenmullers node
Mucocutaneous lymph node syndrome
Sister mary josephs node
Virchows node
Rotter’s lymph nodes are small interpectoral lymph nodes located between the pectoralis major and pectoralis minor muscles. They receive lymphatic fluid from the muscles and the mammary gland, and deliver lymphatic fluid to the axillary lymphatic plexus.

Thoracic duct starts as continuation of cisterna chylii
Crosses from right to left at four level
Passes through aortic opening of diaphragm
The right lymphatic duct drains the right arm, the right side of the chest, and the right side of the head. The thoracic duct drains the rest of the body. Both the right lymphatic duct and the thoracic duct dump into the large venous channels at the base of the neck. Occlusion of this drainage cans produce intractable edema in sites feeding these ducts.

Primary lymphoid organs are Thymus and Bone marrow

Epidermis
Eye
Cornea
Lens
Articular cartilage
Placenta
Bone marrow
Glottis

Arnolds nerve/Aldermans nerve auricular branch of vagus
Nerve of Bell long thoracic nerve
Buffer nerve carotid sinus and vagal fibers from aortic arch
Saphenous nerve longest/largest cutaneous branch of femoral nerve
Herrings nerve branch of glossopharyngeal nerve to carotid sinus
Exners nerve from pharyngeal plexus to cricothyroid membrane
Vidian nerve Greater pertrosal + deep pertrosal nerve (N of Pterygoid canal)
Nerve of Wrisberg: (2 nerves) Nervus intermedius (branch of Facial nerve), medial cutaneous nerve of forearm

Due to abnormal and inappropriate regeneration Auriculotemporal branch of trigeminal nerve there is rednesss, sweating especially on cheeks while eating, talking (gustatory sweating)

Great cerebral vein of Galen is formed by union of internal cerebral veins
Great cerebral vein of Galendrains into straight sinus
Facial vein communicates to cavernous sinus via: Superior ophthalmic vein, inferior ophthalmic vein, deep facial vein
Long saphenous vein is the largest and longest superficial vein of lower limb formed on medial side of dorsal venous arch
Injury to great saphenous vein corresponds to area of femoral nerve distribution.
79The portal vein begins at the level of the second lumbar vertebra and is formed from the convergence of the superior mesenteric and splenic veins. It is 3. 8 cm long and lies anterior to the inferior vena cava and posterior to the neck of the pancreas. It lies obliquely to the right and ascends behind the first part of the duodenum, the common bile duct and gastroduodenal artery. At this point it is directly anterior to the inferior vena cava. It enters the right border of the lesser omentum, and ascends anterior to the epiploic foramen to reach the right end of the porta hepatis. It then divides into right and left main branches which accompany the corresponding branches of the hepatic artery into the liver
Portal vein is formed behind the neck of pancreas by union of superior mesentric and spleenic vein
Normal pressure is 5–10 mm Hg
Portal venous system is valveless.
Left suprarenal drains into left renal vein
Left testicular vein drains into left renal vein
Left ovarian vein drains into left renal vein
Batesons vertebral venous plexus is valveless

Are dilated, tortuous veins and are very common; they may either give no symptoms or cause aching and discomfort in the legs. Varices are recognized as tortuous dilated veins in the leg, a varicose vein is one which permits reverse flow through its faulty valves. Occasionally complications of varicose veins may develop. These include:

Thrombosis: Which is referred to as superficial thrombophlebitis
Sometimes thrombosis extends into the deep venous system to cause Deep vein thrombosis, although this is infrequent
Hemorrhage: Can occur when large superficial varices are damaged
The most serious problem is venous ulceration which complicates varicose veins.

All muscles are mesodermal in origin except muscles of Iris (Sphincter pupillae and dilator pupillae) which are ectodermal
All Pharyngeal arches persist except fifth which disappears
All intrinsic muscles of Larynx are supplied by recurrent laryngeal nerve except cricothyroid which is supplied by external laryngeal nerve
All major salivary gland are supplied by facial nerve except Parotid gland (Although passes through the substance of parotid)
All divisions of Trigeminal nerve except Mandibular division lie in lateral wall of Cavernous sinus
All muscles of pharynx are supplied by pharyngeal plexus except stylopharyngeus which is supplied by Glossopharyngeal nerve.
All muscles of soft palate are supplied by pharyngeal plexus except tensor palate which is supplied by Nerve to medial pterygoid
All muscles of tongue are supplied by hypoglossal nerve except palatoglossus which is supplied by pharyngeal plexus.

Hemoptysis: Bronchial artery
Duodenal ulcer: Gastroduodenal artery
Gastric ulcer: Left Gastric artery
SDH: Bridging veins
EDH: Middle meningeal artery
Tonsillectomy: Paratonsillar vein
Menstruation: Spiral arteries

Duodenal ulcer: The duodenal cap lies just beyond the pylorus. Externally, the cap has attachments to the hepatoduodenal ligament in the pancreatic head. Most of the ulcers occur in the duodenal cap region. The gastroduodenal artery lies directly behind the duodenal cap, and penetrating ulcers into the pancreas initially erode through the gastroduodenal artery, accounting for the massive bleeding that occurs with these ulcers

Extradural hemorrhage: Usually follows arterial hemorrhage between the skull and the dura. Most frequently, acute epidural hematomas occur in the temporal or temporoparietal region as a consequence of hemorrhage from one of the branches of the middle meningeal artery.

Parotid duct: Stensons duct
Submandibular duct: Whartons duct
Pancreatic duct: Wirsungs duct
Accessory pancreatic duct: Santoniris duct
Gartners duct: Remanant of Mesonephric duct (WOLLFIAN)
Thoracic duct: Pecquet duct

Huxles Membrane	Inner layer of cells of root sheath of hair
Henles Membrane	Outer layer of cells of root sheath of hair
Bowmans Membrane	'Anterior’ limiting membrane of Cornea
Decemet’s Membrane	‘Posterior’ limiting membrane of Cornea
Bruchs Membrane	Pigment membrane in Retina
Elschings Membrane	Astroglial membrane covering Optic Disk
Heusers Membrane	Exocelomic Membrane
Sharpnells Membrane	Pars Flaccida of the tympanic membrane

Bergmann Cells
Gitter Cells
Interstitial Cells of Cajal
Supporting Cells of Claudius

Glial cells of Cerebellum
Microglia
Nerve cells of superficial layers of cerebral cortex
Cells in floor of Cochlear canal of inner ear

Dieters Cells
Hensens Cells
Houfbauers Cells
JG Cells
Ito Cells
Langerhans Cells
Langhans Cells
Basket Cells
Gitter Cells
Basket Cells of Cerebellum
Merkel Cells
Muller’s Cells
Hilus Cells
Lacis Cells
Peg Cells
Glomus Cells

Outer hair cells of organ of Corti
Supporting cells in organ of Corti external to Dieters cells
Ellipsoidal cells in chorionic villi of placenta
Smooth muscle cells of afferent arteriole. (kidney)
Stellate cells in liver
Antigen presenting epithelial dendritic cells
Cytotrophoblastic cells of chorionic villi
Myoepithelial cells in salivary/mammary/sweat glands
Microglia of brain
Neurons of molecular layer of Cerebellum
Sensory nerve endings
Neuroglial cells in Retina
Rare cells found in Medulla of Ovary at Hilum of Ovary
Extra glomerular Mesengial Cells outside Glomerulus
Secretory cells in mucosa of uterine tube
Present in Carotid Bodies

81‘Abnormal’ cells

Reed Sternberg cell

These cells characteristically are neoplastic giant cells with a bilobed mirror-image nucleus that may have large (‘owl-eyes’) nucleoli surrounded by a clear halo. Most commonly, these cells are associated with Hodgkin’s disease.

The Langhans cell

It is a giant cell with peripherally arranged nuclei found in granulomas

The LE cell

It is a degenerating neutrophil seen in lupus erythematosus in in vitro preparations

The Mott cell

It is a ‘constipated’ plasma cell filled with immunoglobulins, producing a grape-cluster appearance to the cell. Mott cells are seen in multiple myeloma and some parasitic infestations

The Touton giant cell

Has distributed nuclei and is found in tumors other than Hodgkin’s lymphoma

Diaphragm of oral cavity: Mylohyoid
Diaphragm of Superior thoracic aperture: Sibsons Fascia

Pelvic diaphragm: Levator ani and coccygeus
Urogenital diaphragm: Deep transverse perinea and sphincter urethrae, perineal mermbrane
Diaphragm sella: Fold of duramater overlying pituitary fossa
Iris diaphragm: In eye

Toldts fascia	Anterior renal fascia
Zuckerland fascia	Posterior renal fascia
Bucks fascia	Deep fascia of penis
Denonvillers fascia	Fascia separating rectum from prostate
Waldeyers fascia	Fascia separating rectum from coccyx
Campers fascia	Fatty layer of superficial fascia
Scarpas fascia	Deep membranous layer of Superficial fascia
Fascia Colli	Investing layer of deep cervical fascia of neck
Fascia transversalis	Forms anterior wall of femoral sheath
Fascia iliaca	Forms posterior wall of femoral sheath
Pelvic fascia	Forms hypogastric sheath

USMLE Case Scenario

The Fascial layer separating the rectum from the coccyx is:

Waldeyers Fascia
Fascia Coli
Denonveliers Fascia
Gerota’s Fascia
Cruveilhier’s Fascia
Camper’s Fascia
Colles’ Fascia
Scarpa’s Fascia

Ans. 1. Waldeyers Fascia

Bursitis is inflammation of a bursa, which is a thin-walled sac lined with synovial tissue

The function of the bursa is to facilitate movement of tendons and muscles over bony prominences:

Subacromial bursitis (subdeltoid bursitis) is the most common form of bursitis. Trochanteric bursitis involves the bursa around the insertion of the gluteus medius onto the greater trochanter of the femur.
Olecranon bursitis occurs over the posterior elbow, and when the area is acutely inflamed, infection should be excluded by aspirating and culturing fluid from the bursa. Achilles bursitis involves the bursa located above the insertion of the tendon to the calcaneus and results from overuse and wearing tight shoes.
Retrocalcaneal bursitis involves the bursa that is located between the calcaneus and posterior surface of the Achilles tendon.
Ischial bursitis (weaver’s bottom) affects the bursa separating the gluteus medius from the ischial tuberosity and develops from prolonged sitting and pivoting on hard surfaces.
Iliopsoas bursitis affects the bursa that lies between the iliopsoas muscle and hip joint and is lateral to the femoral vessels.
Anserine bursitis is an inflammation of the sartorius bursa located over the medial side of the tibia just below the knee and under the conjoint tendon and is manifested by pain on climbing stairs.
Prepatellarbursitis (housemaid’s knee) occurs in the bursa situated between the patella and overlying skin and is caused by kneeling on hard surfaces. Treatment of bursitis consists of prevention of the aggravating situation, rest of the involved part, administration of a nonsteroidal anti-inflammatory drug (NSAID), or local glucocorticoid injection.

Housemaid’s knee is the result of inflammation of Prepatellar bursa
Miners beat knee is the result of inflammation of Prepatellar bursa
Clergymans knee is the result of inflammation of subcutaneous infrapatellar bursa

Nutrient artery of clavicle	Suprascapular artery
Nutrient artery of humerus	Profunda brachii artery
Nutrient artery of femur	Second perforating artery. Sometimes by first and third perforating arteries
Nutrient artery of tibia. Largestin body	Posterior tibial artery
Nutrient artery of fibula	Peroneal artery

Axis artery of upper limb: seventh cervical intersemental artery persisting as:

Axillary
Brachial
Anterior interosseous artery and
Deep palmar arch

Axis artery of lower limb: fifth lumbar intersemental artery persisting as:

Inferior gluteal artery
Companion artery of sciatic nerve
Popliteal artery
Peroneal artery and
Plantar arch

The anastomoses of the terminal branches of the ileocolic, right colic and middle colic arteries of the continuous arterial circle or arcade along the inner border of the colon known as the marginal artery of Drummond.

Components

Ileocolic artery - colic branch
Right colic artery – ascending and descending branches
Middle colic artery – right and left branches
Left colic artery – ascending and descending branches
Sigmoid arteries – unnamed terminal branches
- From this marginal artery, straight vessels (known as vasa recta) pass to the colon
- The marginal artery is an important connection between the SMA and IMA, and provides collateral flow in the event of occlusion or significant stenosis. The junction of the SMA and IMA territories is at the:
  - Superior mesentric artery (SMA), and of the left colic and sigmoid branches of the IMA, form a splenic flexure. Anastomoses here are often weak or absent, hence the marginal artery at this point (known as Griffiths’ point) is often focally small or discontinuous. For this reason, the splenic flexure is a watershed area prone to ischemia and infarction
  - One of the commonest area of colonic ischemia is called Sudeck’s point.

Charcots Artery: lenticulostriate arteries which arise at the commencement of the middle cerebral artery supply blood to part of the basal ganglia and posterior limb of the internal capsule. The lenticulostriate perforators are end arteries. The name of these arteries is derived from some of the structures it supplies: the lenticular nucleus and the striatum.

Heubner’s artery: A branch of anterior Cerebral artery, supplies the anteromedial part of the head of the caudate and anteroinferior internal capsule Its vascular territory is the anteromedial section of the caudate nucleus and the anteroinferior section of the internal capsule.

Artery of Adamkiewicz: Arteria Radicularis Magna, Great radicular artery of Adamkiewicz. Provides the major blood supply to the lumbar and sacral cord. When damaged or obstructed, it can result in anterior spinal artery syndrome, with loss of urinary and fecal continence and impaired motor function of the legs; sensory function is often preserved to a degree. It is important to identify the location of the artery when treating a thoracic aortic aneurysm or a thoracoabdominal aortic aneurysm.

The dorsalis pedis artery is the continuation of the anterior tibial artery after the artery anterior tibial artery crosses the ankle to reach the dorsum of the foot
Its pulse is the most distal palpable pulse in the lower limb and therefore is useful for evaluating the arterial supply to the limb
On the dorsum of the foot, the pulse maybe felt as the artery passes over the navicular bone between the extensor hallucis longus tendon and the extensor digitorum longus tendon.

Batson’s vertebral venous plexus: The valveless vertebral venous veins that communicate with the prostatic venous plexus and explain the readiness with which carcinoma of the prostate spreads to the pelvic bones and vertebrae.

Tortuous Arteries

Facial artery
Splenic artery
Uterine artery
Vaginal artery
Ophthalmic artery
Lingual artery
PICA (Post Inferior Cerebellar Artery)

USMLE Case Scenario

A 66-year-old male patient from Florida complains of loss of pain and temperature sensation over the left side body ipsilateral dysphagia, hoarseness, and diminished gag reflex with vertigo and diplopia of two months duration. Most likely tortuous vessel affected is:

AICA
PICA
Common carotid
Internal carotid
Arch of aorta

Ans. 2. PICA: The condition itself is Lateral Medullary (Wallenburgs Syndrome)

Central artery of retina
Central branches of cerebral artery
Coronary artery
Segmental branches of renal/splenic artery

Axillary Artery

It is continuation of subclavian artery
Pectoralis minor divides it into three Branches
- 85Ist part:
  - Superior thoracic artery
- 2nd part:
  - Thoracoacromial artery
  - Lateral thoracic artery
- 3rd part:
  - Subscapular artery
  - Anterior circumflex humeral artery
  - Posterior circumflex humeral artery

No Branches in Neck

Caroticotympanic
Pterygoid
Cavernous branch to trigeminal ganglion
Superior and inferior hypophyseal
Ophthalmic
Anterior cerebral
Middle cerebral
Posterior communicating
Anterior choridal

Superior thyroid
Lingual
Facial
Occipital
Posterior auricular
Ascending pharyngeal
Maxillary
Superficial temporal

Vertebral artery
Internal thoracic artery
Thyrocervical trunk (Inferior thyroid, suprascapular, superficial cervical)
Costocervical trunk (Superior intercostal, Deep cervical)

Spinal
Muscular
Meningeal
Anterior spinal
Posterior spinal
Posterior inferior cerebellar
Medullary

Formed by Union of Two Vertebral Arteries:
Posterior cerebral arteries
Superior cerebellar
Pontine
Labyrinthine
Anteroinferior cerebellar

It is smaller terminal branch of common iliac artery
It is about one and half inches long (3–3.5 cn)
It begins in front of sacroiliac joint
It divides into ant and post Divisions at upper margin of greater sciatic notch

Branches from Anterior Division: (Six in males and seven in females.)

Superior vesical artery
Inf vesical
Obturator
Middle rectal
Inf Gluteal
Internal pudendal
In females, inferior vesical is replaced by vaginal artery
Uterine artery is the 7th branch in females

Branches from Posterior Division

Superior gluteal
IIio lumbar
Lateral sacral

Inferior thyroid artery is a branch of: Thyrocervical trunk
Ascending pharyngeal artery is a branch of external carotid artery
Internal pudendal artery in females is a branch of internal iliac artery
Left gastroepiploic artery is a branch of splenic artery
Splenic artery is a branch of celiac trunk
Uterine artery is a branch of internal iliac artery
Cystic artery is a branch of right hepatic artery
Cilio retinal artery is a branch of choridal artery
Middle meningeal artery is a branch of maxillary artery
Anterior spinal artery is a branch of vertebral artery
Ophthalmic artery is a branch of internal carotid artery

Structure passing between two heads of gastrocnemius: Sural nerve
Structure passing between two heads of lateral pterygoid: Maxillary artery
Structure passing between pronator teres: Median nerve
87Structure passing between two plains of fibers of supinator: Posterior interosseous nerve
Structure passing through tarsal tunnel: Posterior tibial nerve
Structure passing through choroid fissure of eye: Hyaloids artery
Structure passing through foramen of Vesalius: Emissary vein
Structure passing through carotid sheath: Internal carotid/common carotid artery, internal jugular vein, vagus nerve. External carotid is External to sheath
Structure piercing corocabrachialis: Musculocutaneous nerve
Structure piercing clavipectoral fascia (encloses subclavius): Lateral pectoral nerve, thoracoacromial vesses Cephalic vein
Structure piercing thyrohyoid membrane: Internal laryngeal nerve

Axillary nerve accompanies posterior humeral circumflex artery
Radial nerve accompanies profunda brachii vessels
Short saphenous vein accompanies sural nerve
Great saphenous vein accompanies saphenous nerve
Superior thyroid vessels accompany external laryngeal nerve
Superior laryngeal vessels accompany internal laryngeal nerve
Inferior laryngeal vessels accompany recurrent laryngeal nerve

USMLE Case Scenario

Stroking the skin of the medial side of the thigh evokes a reflex contraction of the muscle, the cremasteric reflex, which is most, pronounced in children. It may represent a protective reflex, and the cremaster may also have a role in testicular thermoregulation. Cremaster consists of loosely arranged muscle fasciculi lying along the spermatic cord. It is variable in thickness and is thickest in young men. It may form an incomplete coating around the cord, known as the cremasteric fascia, which extends around the testis but lies within the external spermatic fascia. Cremaster is innervated by:

The terminal branches of the subcostal nerve
The terminal branches of the iliohypogastric nerve
The terminal branches of the ilioinguinal nerve
The genital branch of the genitofemoral nerve
The femoral branch of the genitofemoral nerve

Ans.4. The genital branch of the genitofemoral nerve

USMLE Case Scenario

A 45-year-old man is evaluated by a neurologist because of a gait disorder. When the physician passively moves the patient’s right great toe upward or downward, the patient cannot accurately report the direction of motion. This finding can best be explained by a lesion of which of the following structures?

Right fasciculus cuneatus
Right fasciculus gracilis
Right lateral lemniscus
Right medial lemniscus

Ans: 2. Right fasciculus gracilis

USMLE Case Scenario

As part of a complete neurological examination, a medical student takes a cotton-tipped applicator and touches the patient’s left eye with a thin wisp of cotton as the patient looks to the right. The patient closes both of his eyelids in response. Which of the following cranial nerves is responsible for the motor limb of this reflex?

Abducens
Facial
Optic
Trigeminal

Ans.2. Facial

USMLE Case Scenario

The Epithelium of the Bronchi contains:

Simple ciliated columnar cells, basal cells, and goblet cells
Simple ciliated columnar cells, basal cells, but not goblet cells
Non ciliated columnar cells, basal cells, and goblet cells
Stratified ciliated columnar cells, basal cells, and goblet cells

Ans.4. Stratified ciliated columnar cells, basal cells, and goblet cells

USMLE Case Scenario

The Dandy-Walker malformation is a developmental abnormality in which:

In which the roof of the third ventricle fails to perforate with concomitant hyperplasia of the cerebellar vermis
In which the roof of the fourth ventricle fails to perforate with concomitant hyperplasia of the cerebellar vermis
In which the roof of the third ventricle fails to perforate with concomitant hypoplasia of the cerebellar vermis
In which the roof of the fourth ventricle fails to perforate with concomitant hypoplasia of the cerebellar vermis

Ans.4. In which the roof of the fourth ventricle fails to perforate with concomitant hypoplasia of the cerebellar vermis.

89The Dandy-Walker malformation is a developmental abnormality in which the roof of the fourth ventricle fails to perforate to form the foramen of Magendie. The resultant cystic dilatation of the fourth ventricle expands the posterior fossa, elevating the tentorium and causing hydrocephalus because of obstruction of the aqueduct of Sylvius, with concomitant hypoplasia of the cerebellar vermis.

USMLE Case Scenario

The kidneys and ureter arise from:

The pronephros and a diverticulum from the wolffian duct
The mesonephros and a diverticulum from the wolffian duct
The metanephros and a diverticulum from the wolffian duct
The pronephros and a diverticulum from the gartners duct
The mesonephros and a diverticulum from the gartners duct
The metanephros and a diverticulum from the gartners duct

Ans.2. The mesonephros and a diverticulum from the wolffian duct.

USMLE Case Scenario

From its origin, the uterine artery crosses the ureter anteriorly in the broad ligament before branching at the level of the uterus. One major branch ascends the uterus tortuously within the broad ligament until it reaches the region of the ovarian hilum where it anastomoses with branches of the ovarian artery. The uterine artery arises as a branch of:

The anterior division of the internal iliac artery
The anterior division of the external iliac artery
The posterior division of the internal iliac artery
The posterior division of the external iliac artery
The common iliac artery

Ans.1. The anterior division of the internal iliac artery

USMLE Case Scenario

A 34-year-old patient arrives in the emergency room after having suffered severe head trauma in a accident. Radiographic studies of the head reveal a basilar skull fracture in the region of the foramen ovale. Which of the following nerve passes through this foramen:

Maxillary
Mandibular
Ophthalmic
Occulomotor

Ans.2. Mandibular

USMLE Case Scenario

A Lecturer in Florida is demonstrating a thick fibrous band that runs on the visceral surface of the liver. It is attached on one end to the inferior vena cava and on the other end to the left branch of the portal vein. In the Adult the structure corresponds to:

Ductus venosus
Ligamentum teres
Ligamentum venosum
Umbilical arteries
Ligamentum arteriosum
Ligamentum nucha
Ligament of Treitz

Ans.3. Ligamentum venosum

USMLE Case Scenario

A Lecturer in Florida is demonstrating a fibrous band that runs on the visceral surface of the liver. It is attached on one end to the inferior vena cava and on the other end to the left branch of the portal vein. In the embryo structure corresponds to:

Ductus venosus
Ligamentum teres
Ligamentum venosum
Umbilical arteries

Ans.1. Ductus venosus

USMLE Case Scenario

A 66-year-old driver suffers a stroke while driving on highway. He has a history of hypertension, is a heavy smoker, and drinks beer every weekend A right upper motor neuron paralysis of the facial nerve is noted; the other cranial nerves are normal. He has a hemiplegia on the right side, with equal paralysis of the arm and leg. His lesion most likely involves the:

Left internal capsule
Left midbrain
Left pons
Left medulla

Ans.1. Left internal capsule

Remember:

The anterior limb of the internal capsule conveys frontopontine fibers, the genu conducts corticobulbar fibers, and the posterior limb of the internal capsule conveys corticospinal fibers to the contralateral arm and leg. Hemorrhage of the left internal capsule results in right-sided dense hemiplegia in which paralysis of the arm and leg are of the same intensity.

USMLE Case Scenario

A structure is caused by failure of obliteration of the vitellointestinal duct. It is classically located in the distal ileum within 30 cm of the ileocecal valve, and the structure is a true diverticulum. The anatomist is talking about:

Ligament of Trietz
Meckel’s diverticulum
Appendicis epiploicae
Sacculations

Ans.2. Meckel’s diverticulum

USMLE Case Scenario

A newborn boy does not pass meconium until 48 hours after his birth. Several weeks later his mother complains that he has not been passing stool regularly. Anorectal manometry reveals increased internal anal sphincter pressure on rectal distention with a balloon. The patient’s disorder maybe attributed to distention with a balloon. The patient’s disorder maybe attributed to:

Defective recanalization of the colon
91Failure of neural crest cells to migrate
Herniation of abdominal contents into the umbilical cord
Persistence of the proximal end of the yolk stalk

Ans.2. Failure of neural crest cells to migrate

USMLE Case Scenario

The vagina is a muscular tube lined with:

Non stratified squamous epithelium that is histologically similar to the mucosa of the cervix and vulva
Stratified squamous epithelium that is histologically similar to the mucosa of the cervix and vulva
Stratified cuboidal epithelium that is not histologically similar to the mucosa of the cervix and vulva
Stratified cuboidal epithelium that is histologically similar to the mucosa of the cervix and vulva

Ans.2. Stratified squamous epithelium that is histologically similar to the mucosa of the cervix and vulva.

USMLE Case Scenario

A 5-year-old child aspirates a peanut. Following bronchopulmonary segments would this foreign object most likely enter.

Superior segment of the right lower lobes
Inferior segment of the right lower lobe
Superior segment of the left lower lobe
Superior segment of the left lower lobe

Ans.1. Superior segment of the right lower lobe

Because the right main bronchus is wider and more vertical than the left, foreign objects are more likely to be aspirated into the right main bronchus. The superior segmental bronchus of the lower lobar bronchus is the only segmental bronchus that exits from the posterior wall of the lobar bronchi. Therefore, if a patient is supine at the time of aspiration, the object is most likely to enter the superior segmental bronchus of the lower lobe.

USMLE Case Scenario

Fracture of neck of Fibula produces foot drop due to injury of:

Common peroneal nerve
Tibial nerve
Obturator nerve
Femoral nerve

Ans: 1. Common peroneal nerv

USMLE Case Scenario

Which of the following embryonic structures gives rise to the adrenal cortex?

Ectoderm
Endoderm
Mesoderm
Mesonephros

Ans.3. Mesoderm

USMLE Case Scenario

The modified structures at the border of the epithelium are villi which are immotile in a patient. Which of the following would be a consequence of this lack of motility?

Implantation failure
Kartagener’s syndrome
92Increased gut motility
Decreased protein absorption

Ans.2. Kartagener’s syndrome

USMLE Case Scenario

The arterial blood supply to the palatine tonsil is derived from branches of the external carotid artery. The principal artery is the tonsillar artery, which is a branch of the:

Facial artery
Lingual artery
Superficial temporal artery
Maxillary artery
Superior thyroid artery

Ans.1. Facial artery

USMLE Case Scenario

Occlusion of which artery would result in insufficient perfusion of the urinary bladder:

Internal iliac
External iliac
Renal
Suprarenal

Ans.1. Internal iliac

USMLE Case Scenario

Statement True about Esophagus is:

The upper 2/3 of the esophagus contains striated muscle and is innervated by the vagus nerve (CNX). The lower 1/3 contains smooth muscle from splanchnic mesoderm and is innervated by the splanchnic plexus
The lower 2/3 of the esophagus contains striated muscle and is innervated by the vagus nerve (CNX). The upper 1/3 contains smooth muscle from splanchnic mesoderm and is innervated by the splanchnic plexus
The upper 2/3 of the esophagus contains smooth muscle and is innervated by the vagus nerve (CNX). The lower 1/3 contains skeletal muscle from splanchnic mesoderm and is innervated by the splanchnic plexus
The upper 2/3 of the esophagus contains striated muscle and is innervated by the splanchnic plexus. The lower 1/3 contains smooth muscle from splanchnic mesoderm and is innervated by the vagus nerve

Ans.1. The upper 2/3 of the esophagus contains striated muscle and is innervated by the vagus nerve (CNX). The lower 1/3 contains smooth muscle from splanchnic mesoderm and is innervated by the splanchnic plexus.

USMLE Case Scenario

The mesentery, a large fold of peritoneum, suspends the small intestine from the posterior abdominal wall. The base of the mesentery attaches to the posterior abdominal wall:

To the right of the third lumbar vertebra and passes obliquely to the left and inferiorly to the right sacroiliac joint
To the left of the third lumbar vertebra and passes obliquely to the left and inferiorly to the right sacroiliac joint
To the right of the second lumbar vertebra and passes obliquely to the left and inferiorly to the right sacroiliac joint
To the left of the second lumbar vertebra and passes obliquely to the right and inferiorly to the right sacroiliac joint

Ans.4. To the left of the second lumbar vertebra and passes obliquely to the right and inferiorly to the right sacroiliac joint.

The mesentery contains blood vessels, nerves, lymphatics, and lymph nodes, as well as considerable fat. It attaches to the small intestine along the length of one side, the mesenteric border, leaving the remainder of the surface of the bowel covered by its visceral peritoneum, the serosa. The broad-based attachment of the mesenteric base stabilizes the small bowel and prevents it from twisting upon its blood supply.

USMLE Case Scenario

93A 33-year-old person from Toledo is hit by a car has been said to develop extradural hematom1. Most likely vessel to bleed is:

Ophthalmic artery
Subdural veins
Occipital artery
Middle meningeal artery

Ans.4. Middle meningeal artery

USMLE Case Scenario

During an abdomino pelvic surgery a big, tortuous vessel was seen by a gynecologist on the lateral side of uterus. The vessel was found to be a branch of internal iliac artery. Most likely the vessel found by the gynecologists was:

Splenic artery
Ovarian artery
Vaginal artery
Uterine artery

Ans.4. Uterine artery

USMLE Case Scenario

A surgeon wishes to perform a splenectomy on a 77-year-old patient who has been in an automobile accident. Before removing the spleen, the splenic artery and splenic vein are ligated. Within which of the following peritoneal structures are the splenic artery and vein found?

Gastrocolic ligament
Gastrosplenic ligament
Lesser omentum
Splenorenal ligament

Ans.4. Splenorenal ligament

USMLE Case Scenario

A 44-year-old has a normal thyroid gland which normally moves with swallowing because the thyroid gland is enclosed by which of the following fascia?

Carotid sheath
Investing layer of the deep cervical fascia
Pretracheal fascia
Prevertebral fascia

Ans.3. Pretracheal fascia

USMLE Case Scenario

A 15-year-old typist from ilinos comes to the health clinic because of recurrent episodes of wheezing during basketball practices. His activity has been hampered by shortness of breath shortly after beginning practice and during games. The symptoms are accompanied by a nonproductive cough and chest tightness. He denies any symptoms at rest. The symptoms occur whether the practices are indoors or outdoors. On physical examination, he is comfortable and denies any symptoms. His physical examination is unremarkable. Which of the following cells are most likely to mediate his symptoms?

Eosinophils
Lymphocytes
Mast cells
Monocytes
Neutrophils

94Ans. 3. Mast cells

This patient has symptoms of exercise-induced asthma. The symptoms of exercise-induced asthma are due to mast cell release of histamines, which degranulate with the initiation of exercise.

USMLE Case Scenario

Carotid Sheath is an important structure. It contains a cranial nerve. The cranial nerve is:

IX
X
XI
XII

Ans.2. X

USMLE Case Scenario

The cranial nerve passing through the substance of parotid gland is:

Abducens
Facial
Optic
Trigeminal
Glossopharyngeal
Vagus

Ans.2. Facial

USMLE Case Scenario

A feature of Sharipos Syndrome is agenesis of:

Corpus callosum
Anterior commisure
Posterior commisure
Hippocampal commisure

Ans. 1. Corpus callosum

USMLE Case Scenario

During cranial nerve examination, a neurologist asks her 33-year-old patient to protrude his tongue. On doing so, her tongue deviates to the right side. This finding results from paralysis of tongue muscle namely:

Genioglossus
Styloglossus
Palatoglossus
Hyoglossus

Ans.1. Genioglossus

The genioglossus muscle is innervated by the hypoglossal nerve. The function of the genioglossus muscle is to pull the tongue forward (protrude) and toward the opposite side. When the right genioglossus muscle is paralyzed, the left genioglossus muscle pulls the tongue forward and to the right.

USMLE Case Scenario

Bells Palsy is a LMNL of a cranial nerve. The cranial nerve most commonly involved is:

Abducens
Facial
Optic
Trigeminal

Ans.2. Facial

USMLE Case Scenario

95An inflammatory process in the temporal bone has resulted in a swelling of the facial nerve within the facial canal. Which muscle maybe paralyzed as a result of this compression?

Anterior belly of the digastrics
Geniohyoid
Stapedius
Stylopharyngeus

Ans.3. Stapedius

The stapedius muscle is innervated by the facial nerve. This muscle is located in the middle ear and attaches to the neck of the stapes. Contraction of the Stapedius reduces the amplitude of oscillation of the stapes and thus reduces the perceived loudness of a sound. Paralysis of this muscle may result in hyperacusis.

USMLE Case Scenario

A 34-year-old male smoker notices loss of taste sensation in his anterior part of tongue. He reports to a physician who tells him that one of his nerves maybe damaged which supplies taste sensation to this part of his tongue. The nerve specifically most likely to be damaged is:

Glossopharyngeal
Lingual
Chorda tympani
Vagus

Ans.3. Chorda tympani

USMLE Case Scenario

The neck of the pancreas links the head and body. It is often the most anterior portion of the gland. The lower part of the neck lies anterior to the superior mesenteric vein. This is important during surgery for pancreatic cancer since malignant involvement of these vessels may make resection impossible. The anterior surface of the neck is covered with peritoneum. The posterior surface of neck is closely related to:

Pylorus of stomach
Aorta
Internal iliac vein
External iliac vein
Common iliac vein
Portal vein

Ans.6. Portal vein

The neck of the pancreas is defined as that portion of the pancreas which lies anterior to the portal vein, and is closely related to the upper posterior surface. The lower part of the neck lies anterior to the superior mesenteric vein just before the formation of the portal vein.

USMLE Case Scenario

An ENT surgeon plainly tells his patient from North Carolina that he has got hyperacusis and that one of his important nerve is damaged. The nerve most likely to be damaged is:

Auriculotemporal
Greater Auricular
Auricular branch of Vagus
Nerve to Stapedius

Ans.4. Nerve to Stapedius

USMLE Case Scenario

A 66-year-old patient from Ohio has a large meningioma involving the parasagittal region and falx cerebri neurologic deficits expected to be produced by mass lesion in this region is:

Lower limb paralysis
96Upper limb paralysis
Motor aphasia
Sensory aphasia

Ans.1. Lower limb paralysis

A meningioma of the parasagittal region and the falx cerebri would be located superiorly, between the two hemispheres. In this position, it could compress the sensory (postcentral gyrus) or motor cortex (precentral gyrus) supplying the lower extremities and cause lower limb paralysis.

USMLE Case Scenario

A 66-year-old man working in a bar complains of trouble swallowing and hoarseness. On physical exam, he is noted to have ptosis and a constricted pupil on the left, and a diminished gag reflex. Neurological examination shows decreased pain and temperature sensation on the left side of his face and on the right side of his body. Which vessel is most likely occluded?

Spinal artery
PICA
AICA
Vertebral artery

Ans.2. PICA

The signs and symptoms in this patient are consistent with occlusion of the posterior inferior cerebellar artery (PICA). PICA is a branch of the vertebral artery (which is itself a branch of the subclavian artery). Occlusion of PICA causes a lateral medullary syndrome characterized by deficits in pain and temperature sensation over the contralateral body (spinothalamic tract dysfunction); ipsilateral dysphagia, hoarseness, and diminished gag reflex (interruption of the vagal and glossopharyngeal pathways); vertigo, diplopia, nystagmus and vomiting (vestibular dysfunction); ipsilateral Horner’s syndrome (disruption of descending sympathetic fibers); and ipsilateral loss of pain and temperature sensation of the face (lesion of the spinal tract and nucleus of the trigeminal nerve).

USMLE Case Scenario

Vessel lying within cavernous sinus is:

Internal carotid
External carotid
Common carotid
External jugular vein

Ans.1. Internal carotid

USMLE Case Scenario

A 55-year-old male received a hit on left hypochondriac region. Spleen was found to be lacerated. On operation, a large tortuous vessel was found to be seen. Doctor reported it as splenic artery. It is a branch of:

Celiac trunk
Superior mesenteric artery
Inferior mesenteric artery
Thoracic aorta

Ans.1. Celiac trunk

USMLE Case Scenario

A 55-year-old male had a surgery. His leino renal ligament was seen to contain an artery. Most likely the artery was:

Short gastric artery
Splenic artery
Pancreatic artery
Renal artery

Ans.2. Splenic artery

USMLE Case Scenario

A 55-year-old is to be operated for inguinal hernia. An antomist while discussing the hernia describes one artery as a land mark for differentiating direct and indirect inguinal hernias. The artery most likely is:

Superior epigastric artery
Inferior epigastric artery
Umbilical artery
Obliterated umbilical artery

Ans. 2. Inferior epigastric artery

Remember:

Indirect inguinal hernias lie lateral to the inferior epigastric artery, whereas direct inguinal hernias lie medial to these vessels.

USMLE Case Scenario

The superficial perineal fascia is a continuation into the perineum of the membranous fascia from the anterior abdominal wall. The superficial perineal fascia is called as:

Colles fascia
Fascia colli
Campers fascia
Waldeyers fascia
Thoraco lumbar fascia

Ans.1. Colles fascia

USMLE Case Scenario

An aneurysm of the axillary artery within the axilla is most likely to compress which of the following neural structures?

Axillary nerve
Long thoracic nerve
Lower trunk of the brachial plexus
Medial cord of the brachial plexus

Ans. 4. Medial cord of the brachial plexus

Remember:

Within the axilla, the axillary artery is within the axillary sheath and is surrounded by the three cords of the brachial plexus, which are also within the axillary sheath. An aneurysm of the axillary artery may compress any of the three cords.

USMLE Case Scenario

Physical examination of 32-year-old medical graduate from kansas reveals a winged left scapula and an inability to raise his left arm above the horizontal. Which of the following nerves is most likely affected?

Axillary nerve
Long thoracic nerve
Lower subscapular
Suprascapular nerve

Ans.2. Long thoracic nerve

Remember:

The serratus anterior, innervated by the long thoracic nerve, is responsible for stabilization of the scapula during abduction of the arm from 90 to 180 degrees. When the long thoracic nerve is damaged, it is difficult to elevate the arm above the horizontal. This nerve arises from C5, 6, and 7. Remember: ‘winged scapula’ is a classic clue for long thoracic nerve injury.

USMLE Case Scenario

Waldeyer’s ring is a circumpharyngeal ring of mucosa-associated lymphoid tissue which surrounds the openings into the digestive and respiratory tracts. It is made-up:

Posterosuperiorly by the lingual tonsil
98Anterosuperiorly by the lingual tonsil
Posteroinferiorly by the lingual tonsil
Anteroinferiorly by the lingual tonsil

Ans.4. Anteroinferiorly by the lingual tonsil

Waldeyers Ring: Anteroinferiorly by the lingual tonsil, laterally by the palatine and tubal tonsils, and posterosuperiorly by the nasopharyngeal tonsil

USMLE Case Scenario

A 33-year-old female engineer complains to her orthopedician that her thumb does not work right. The physician notes weakness of the thumb in extension, although rotation, flexion, abduction, adduction, and opposition are normal. Which of the following nerves is most likely involved?

Ulnar
Radial
Median
Axillary

Ans.2. Radial

Redial extension is provided by the extensors pollicis longus and brevis, which are innervated by the radial nerve
The median nerve supplies the thenar group, which allows the thumb to oppose, flex, abduct, and rotate
The ulnar nerve supplies the adductor pollicis, which adducts the thumb
Axillary nerve supplies Teres Minor and Deltoid.

USMLE Case Scenario

A branch of the posterior cord of the brachial plexus particularly susceptible to injury in shoulder dislocations that displace the humeral head with impaired Arm abduction and loss of sensation over the lower half of the deltoid. The nerve involved is:

Ulnar
Radial
Median
Axillary

Ans.4. Axillary

USMLE Case Scenario

A nerve innervates the muscle of the anterior compartment of the arm but does not innervate any muscle in the hand is:

Ulnar
Radial
Musculocutaneous
Median

Ans.3. Musculocutaneous

USMLE Case Scenario

A 36-year-old Acromegaly patient complains of a tingling sensation in the 1st, 2nd, and 3rd digits of the right hand and loss of coordination and strength of the right thumb. The condition is most likely to be:

Claw hand
Carpal tunnel syndrome
Ape hand deformity
Dupynterns contracture

Ans.2. Carpal tunnel syndrome

Overgrowth in the wrist area has compressed the carpal tunnel, thereby impinging on the median nerve. The median nerve (root C5-T1) provides motor innervation to the forearm flexors, thenar muscles, and radial lumbricals. It provides sensory innervation to the radial 2/3 of the palm, volar surfaces of the thumb, 2nd and 3rd digits, and radial 1/2 of the 4th digit.

USMLE Case Scenario

A 55-year-old suffered trauma to his penis. His Dorsal artery of penis got damaged. The said vessel is a branch of:

Anterior division of internal iliac artery
Posterior division of internal iliac artery
Anterior division of external iliac artery
Posterior division of external iliac artery

Ans.1. Anterior division of internal iliac artery

The internal pudendal is a branch of the anterior division of the internal iliac artery. It gives rise to the inferior rectal artery, perineal artery, artery of the bulb in men, urethral artery, deep artery of the penis and dorsal artery of the penis.

USMLE Case Scenario

A 66-year-old reports pain in his left upper extremity and tingling and numbness in his 4th and 5th digits of his left hand. There is mild swelling of the left hand. The man reports most of his pain and numbness occurs when he is doing electric work with his arms overhead. X-ray reveals the presence of a cervical rib. The artery liable to be compressed is:

Axillary
Radial
Brachial
Subclavian

Ans.4. Subclavian

The subclavian artery passes laterally over the upper surface of the first rib and lies posterior to the scalenus anterior. In the case of thoracic outlet syndrome, this artery is usually compressed between the scalenus anterior and a cervical rib. Thoracic outlet syndrome is a broad term for a group of disorders in which there is compression of certain neurovascular bundles. The presence of a cervical rib adds to the compression, and repetitive motion and poor posture are other predisposing factors. When the neurovascular bundle is entrapped, the patient presents with neurological and/or circulatory changes in the upper extremity on the involved side.

USMLE Case Scenario

A 44-year-old complains of Galactorrhea and Amonorrhea. CT Scan was done. Image shows a pituitary tumor compressing optic chiasma. Hemianopia produced would be of type:

Bitemporal hemianopia
Binasal hemianopia
Unilateral hemianopia
Superior quadrant unilateral hemianopia

Ans.1. Bitemporal hemianopia

USMLE Case Scenario

The person shown in figure has features as identified in figure. Most likely he is suffering from a disease that affects which part of CNS.

Cerebellum
Substantia nigra
Nucleus basalis
Frontal lobe

Ans.2. Substantia nigra

USMLE Case Scenario

The chorda tympani nerve of is a branch of cranial nerve. The cranial nerve is:

Abducens
Facial
Optic
Trigeminal

Ans.2. Facial

USMLE Case Scenario

A 45-year-old from India notices swelling in his groin. He is reported to have an abscess after further investigations reveal tuberculosis of spine. The abscess is found along sheath of a muscle whose function is: to flex the thigh at the hip. The muscle involved is:

Gluteus maximus
Psoas
Gluteus minimus
Sartorius

Ans.2. Psoas

USMLE Case Scenario

Pyramidalis is a triangular muscle that lies in front of the lower part of rectus abdominis within the rectus sheath. It is attached by tendinous fibers to the front of the pubis and to the ligamentous fibers in front of the symphysis. The muscle diminishes in size as it runs upwards, and ends in a pointed apex that is attached medially to the linea alba. This attachment usually lies midway between the umbilicus and pubis, but may occur higher. The pyramidalis is supplied by:

The terminal branches of the subcostal nerve
The terminal branches of the iliohypogastric nerve
The terminal branches of the ilioinguinal nerve
The terminal branches of the genitofemoral nerve

Ans.1. The terminal branches of the subcostal nerve

USMLE Case Scenario

The muscles of the pharynx with the exception of one muscle are supplied from the pharyngeal plexus by the pharyngeal branch of the vagus. The exception is:

Palatopharyngeus
Stylopharyngeus
Salpingopharyngeus
Inferior constrictor

Ans. 2. Stylopharyngeus

The muscles of the pharynx-with the exception of stylopharyngeus, which is supplied by the glossopharyngeal nerve are supplied from the pharyngeal plexus by the pharyngeal branch of the vagus. This branch emerges from the upper part of the inferior vagal ganglion.

USMLE Case Scenario

The paired renal arteries supply the kidneys through a number of subdivisions described sequentially as segmental, lobar, interlobar, and arcuate arteries. These are end arteries with no anastomoses. The renal arteries branch laterally from the:

Iliac vessels just below the origin of the superior mesenteric artery
Iliac vessels just above the origin of the superior mesenteric artery
Aorta just below the origin of the superior mesenteric artery
102Aorta just above the origin of the superior mesenteric artery

Ans.3. Aorta just below the origin of the superior mesenteric artery

The renal arteries branch laterally from the aorta just below the origin of the superior mesenteric artery. Both cross the corresponding crus of the diaphragm at right angles to the aorta. The right renal artery is longer and often higher, passing posterior to the inferior vena cava, right renal vein, head of the pancreas and descending part of the duodenum. The left renal artery is a little lower and passes behind the left renal vein, the body of the pancreas and splenic vein.

USMLE Case Scenario

The aortic aperture is the lowest and most posterior of the large openings. It is at the level of the lower border of the twelfth thoracic vertebra and the thoracolumbar intervertebral disk, slightly to the left of the midline. It is an osseoaponeurotic opening defined by the diaphragmatic crura laterally, the vertebral column posteriorly and the diaphragm anteriorly. Strictly speaking, it lies behind the diaphragm and its median arcuate ligament. The aortic opening transmits:

The aorta, thoracic duct, azygos veins
The inferior vena cava, thoracic duct, azygos veins
Esophagus, thoracic duct, azygos veins
The phrenic nerve, thoracic duct, azygos veins

Ans.1. The aorta, thoracic duct, azygos veins

USMLE Case Scenario

The epithelial lining of the trachea is composed of:

Pseudostratified columnar nonciliated cells, goblet cells and basal cells
Pseudostratified columnar ciliated cells, goblet cells and basal cells
Stratified columnar nonciliated cells, goblet cells and basal cells
Stratified noncolumnar ciliated cells, goblet cells and basal cells

Ans.2. Pseudostratified columnar ciliated cells, goblet cells and basal cells

USMLE Case Scenario

Kidney is surrounded by a special layer of fascia called:

Waldeyers fascia
Fascia coli
Denonveliers fascia
Gerota’s fascia
Cruveilhier’s fascia
Camper’s fascia
Colles’ fascia
Scarpa’s fascia

Ans.4. Gerota’s fascia

USMLE Case Scenario

The ovarian vessels follow a downward course and pass between the layers of the infundibulopelvic ligament and the broad ligament to reach the ovary. The true statement regarding blood supply of ovary is:

The ovarian arteries arise from aorta, the left ovarian vein and the right ovarian vein empties into the vena cava
The ovarian arteries arise from aorta and the left ovarian vein empties into the left renal vein; the right ovarian vein empties into the vena cava
The ovarian arteries arise from uterine artery and the right ovarian vein empties into the left renal vein; the left ovarian vein empties into the vena cava
The ovarian arteries arise from uterine artery and the left ovarian vein empties into the left renal vein; the right ovarian vein empties into the vena cava

Ans.2. The ovarian arteries arise from aorta and the left ovarian vein empties into the left renal vein; the right ovarian vein empties into the vena cava.

USMLE Case Scenario

A 44-year-old suffers fracture of surgical neck of humerus. Most likely effected nerve is:

Radial
Musculocutaneous
Ulnar
Anterior interosseous c nerve
Cranial nerve XI
Subscapular
Axillary nerve

Ans.7. Axillary nerve

USMLE Case Scenario

Valves of Kerckring are seen in:

Appendix
Small intestine
Cecum
Sigmoid colon
Rectum
Anal canal

Ans.2. Small intestine

The mucosal surface of the small intestine contains numerous circular mucosal folds called the plicae circulares (valvulae conniventes, or valves of Kerckring). These folds are 3 to 10 mm in height; they are taller and more numerous in the distal duodenum and proximal jejunum, becoming shorter and fewer distally. Intestinal villi barely visible to the naked eye resemble tiny finger-like processes projecting into the intestinal lumen.

USMLE Case Scenario

A nerve innervates the anconeus muscle of the arm. Most likely nerve supply of anconeus is:

Ulnar
Radial nerve
Musculocutaneous
Median

Ans.2. Radial nerve

USMLE Case Scenario

The cranial nerves lying in the cavernous sinus are:

VII, IX
X, XI
XII, VI
Divisions of V nerve
Divisions of VII nerve

Ans.4. Divisions of V nerve

USMLE Case Scenario

Annular bronchial cartilage is congenitally absent, leading to bronchomalacia and Bronchiectasis is termed as:

Cystic fibrosis syndrome
Ehlers-Danlos syndrome
Mounier-Kuhn syndrome
Kartageners syndrome
Immotile cilia syndrome
Williams-Campbell syndrome

Ans.6. Williams-Campbell syndrome

USMLE Case Scenario

Fold of serous pericardium surrounding right and left pulmonary veins are connected by an irregular pericardial reflection creates a space termed the:

Oblique sinus
Transverse sinus
Coronary sinus

Ans.1. Oblique sinus

USMLE Case Scenario

After a fight a sharp instrument passed through the superior orbital fissure of a 45-year-old man. It would most likely damage the:

Abducens nerve
Facial nerve
Mandibular nerve
Maxillary nerve
Middle meningeal artery
Ophthalmic artery
Optic nerve

Ans.1. Abducens nerve

Almost everything that innervates the eye, other than the optic nerve, passes through this fissure. This includes the oculomotor nerve (CN III), the trochlear nerve (CN IV), the ophthalmic nerve (V1), and the abducens nerve (CN VI).

USMLE Case Scenario

Meckel’s Diverticulitis is persistence of:

Portion of the vitelline duct on the mesenteric border of the distal ileum, may produce bleeding, intestinal obstruction
Portion of the vitelline duct on the mesenteric border of the proximal ileum, may produce bleeding, intestinal obstruction
Portion of the vitelline duct on the antimesenteric border of the proximal ileum, may produce bleeding, intestinal obstruction
Portion of the vitelline duct on the antimesenteric border of the distal ileum, may produce bleeding, intestinal obstruction

Ans.4. Portion of the vitelline duct on the antimesenteric border of the distal ileum, may produce bleeding, intestinal obstruction

USMLE Case Scenario

A 27-year-old woman presents with hyperthyroidism, and subtotal thyroidectomy is successfully performed, but following the surgery, the woman is extremely hoarse, and can barely speak above a whisper. This hoarseness is most probably related to damage to a nerve which is a branch of CRANIAL NERVE:

IX
X
XI
XII

Ans.2. X

USMLE Case Scenario

A physician is performing a cranial nerve examination on a patient. While testing the gag reflex, it is noted that when the right side of the pharyngeal mucosa is touched, the patient’s uvula deviates to the right. When the left side of the pharyngeal mucosa is touched, the patient does not gag. Which of the following is the most likely location of his lesion?

Left glossopharyngeal nerve and left vagus nerve
Right glossopharyngeal nerve and left vagus nerve
Left glossopharyngeal nerve and Right vagus nerve
Right glossopharyngeal nerve and Right vagus nerve

Ans.1. Left glossopharyngeal nerve and left vagus nerve

USMLE Case Scenario

A cranial nerve innervates the stylopharyngeus muscle and the parotid gland. Visceral afferents supply the carotid sinus baroreceptors and carotid body chemoreceptors, and mediate taste from the posterior one-third of the tongue. Somatosensory fibers supply pain, temperature, and touch information from the posterior one-third of the tongue, upper pharynx, middle ear and eustachian tube. The cranial nerve mentioned is:

IX
X
XI
XII

Ans.1. IX

USMLE Case Scenario

An injury to the lateral portion of the dorsal columns would most likely damage:

Fine motor control of fingers
Motor control of the contralateral foot
Sweating of the ipsilateral face
Proprioception from the ipsilateral leg
Vibratory sense from the ipsilateral arm
Vibratory sense from the contralateral arm
Sensory control of the contralateral foot

Ans. 5. Vibratory sense from the ipsilateral arm

USMLE Case Scenario

Atresia (blockage) of this canal results from failure of the meatal plug to canalize. Usually the deep part of the meatus is open, but the superficial part is blocked by bone or fibrous tissue. Most cases are associated with the:

First arch syndrome
Second arch syndrome
Third arch syndrome
Fifth arch syndrome

Ans.1. First arch syndrome

USMLE Case Scenario

The tensor tympani muscle, attached to the malleus, is derived from mesenchyme in the first pharyngeal arch and is innervated by:

CN V, the nerve of this arch
CN VI, the nerve of this arch
CN VII, the nerve of this arch
CN VIII, the nerve of this arch

Ans.1. CN V, the nerve of this arch

USMLE Case Scenario

Fine motor control of the fingers would be carried principally by the:

Contralateral lateral corticospinal tract
Ipsilateral lateral corticospinal tract
Ipsilateral rubrospinal tract
Ipsilateral Tectospinal tract
Ipsilateral vestibulospinal tract

Ans.2. Ipsilateral lateral corticospinal tract

USMLE Case Scenario

The rectum is separated from the prostate by:

Waldeyers fascia
Fascia coli
Denonveliers fascia
Gerota’s fascia
Cruveilhier’s fascia
Camper’s fascia
Colles’ fascia
Scarpa’s fascia

Ans.3. Denonveliers fascia

USMLE Case Scenario

An 89 years old elderly patient suffering from Picks disease also had multiple small strokes. During her stay in the nursing home on multiple occasions she aspirated food, and neurological examination reveals that her gag reflex is absent. These findings suggest involvement of the nucleus of which of the following cranial nerves?

Facial (VII)
Glossopharyngeal (IX)
Hypoglossal (XII)
Spinal accessory (XI)
Vestibulocochlear (VIII)

Ans.2. Glossopharyngeal (IX)

Cranial nerve IX is the glossopharyngeal nerve, which has a nucleus in the medulla and is necessary for the gag reflex

USMLE Case Scenario

The esophagus begins at the lower border of the cricoid cartilage at the level of C6 vertebra. It is about 25 cm (10 inches) long. The intra-abdominal part of the esophagus varies in length according to the tone of its muscle and the degree of distension of the stomach. It passes through the diaphragm at the level of:

T6 vertebra
T8 vertebra
T10 vertebra
T12 vertebra

Ans.3. T10 vertebra

USMLE Case Scenario

The upper part of the anal canal above the pectinate line is endodermal, and the lower part is derived from the ectoderm. The upper half of the canal is lined by columnar epithelium and the lower half with stratified squamous epithelium. True statement would be:

A carcinoma of the lower canal is usually an adenocarcinoma, while that arising from the upper part would be a squamous cell carcinoma
A carcinoma of the upper canal is usually an adenocarcinoma, while that arising from the lower part would also be an adenocarcinoma
A carcinoma of the upper canal is usually a squamous cell carcinoma, while that arising from the lower part would also be a squamous cell carcinoma
A carcinoma of the upper canal is usually an adenocarcinoma, while that arising from the lower part would be a squamous cell carcinoma

Ans.4. A carcinoma of the upper canal is usually an adenocarcinoma, while that arising from the lower part would be a squamous cell carcinoma

USMLE Case Scenario

The cranial nerve carrying the pain sensations from tip of tongue is:

VI
V2
V3
VII
IX
X
XI
XII

Ans.3. V3

The mandibular division of the trigeminal nerve (V3) carries general somatic sensation from the anterior two-thirds of the tongue.

USMLE Case Scenario

Which of the following eye muscles rotates the eye downward and away from midline?

Inferior oblique
Superior oblique
Inferior rectus
Superior rectus

Ans.2. Superior oblique

USMLE Case Scenario

A 44-year-old engineer noticed that he has an eye that is persistent directed toward his nose. A lesion of which of the following nerves could produce this finding?

CN II
CN IV
CN V
CN VI

Ans.4. CN VI

USMLE Case Scenario

The Fascial layer separating the rectum from the coccyx is:

Waldeyers fascia
Fascia coli
Denonveliers fascia
Gerota’s fascia
Cruveilhier’s fascia
Camper’s fascia
Colles’ fascia
Scarpa’s fascia

Ans.1. Waldeyers fascia

USMLE Case Scenario

Carotid Sheath is an important structure. It contains:

Facial nerve and internal carotid artery
Facial nerve and external carotid artery
Facial artery and external carotid artery
Vagus nerve and external carotid artery
Vagus nerve and internal carotid artery

Ans.5. Vagus nerve and internal carotid artery

USMLE Case Scenario

Meckels ganglion is related to a cranial nerve. The cranial nerve is:

Abducens
Facial
Optic
Trigeminal

Ans.4. Trigeminal

USMLE Case Scenario

The cranial nerve supplying the Trapezius muscle is:

VII
IX
X
XI
XII

Ans.4. XI

USMLE Case Scenario

A Nerve innervating the muscles of the Posterior compartment of the arm is:

Ulnar
Radial
Musculocutaneous
Median

Ans.2. Radial

USMLE Case Scenario

Physical examination of 36-year-old medical graduate from Texas reveals a winged left scapula and an inability to raise his left arm above the horizontal. Which of the following muscles is most likely affected?

Serratus posterior
Serratus anterior
Deltoid
Scalenus anterior
Scalenus medius
Scalenus posterior
Levator scapulae
Sternomastoid
Rhombidius minor

Ans.2. Serratus anterior

Remember:

The serratus anterior, innervated by the long thoracic nerve, is responsible for stabilization of the scapula during abduction of the arm from 90 to 180 degree.

USMLE Case Scenario

A Newborn boy does not pass meconium until 55 hours after his birth. Several weeks later his mother complains that he has not been passing stool regularly. Anorectal manometry reveals increased internal anal sphincter pressure on rectal distention with a balloon. The patient’s disorder is:

Intussusception
Hirschsprungs disease
Exomphalos
Dysphagia lusoria
Anal atresia
Malrotation of gut

Ans.2. Hirschsprungs disease

USMLE Case Scenario

A physician during cranial nerve examination asks her patient to protrude his tongue. On doing so, her tongue deviates to the right side. This finding results from paralysis of tongue muscle. The likely nerve paralyzed is:

Facial
Vagus
Hypoglossal
Glossopharyngeal
Chorda tympani
Lingual

Ans. 3. Hypoglossal

The genioglossus muscle is innervated by the hypoglossal nerve. The function of the genioglossus muscle is to pull the tongue forward (protrude) and toward the opposite side. When the right genioglossus muscle is paralyzed, the left genioglossus muscle pulls the tongue forward and to the right.

USMLE Case Scenario

As part of a complete neurological examination, a medical student takes a cotton-tipped applicator and touches the patient’s left eye with a thin wisp of cotton as the patient looks to the right. The patient closes both of his eyelids in response. Which of the following cranial nerves is responsible for the sensory limb of this reflex?

Abducens
Facial
Optic
Trigeminal

Ans.4. Trigeminal

USMLE Case Scenario

A 34-year-old patient arrives in the emergency room after having suffered severe head trauma in a accident. Radiographic studies of the head reveal a basilar skull fracture in the region of the foramen ovale. Which of the following nerve passes through this foramen:

Maxillary
110Mandibular
Ophthalmic
Occulomotor

Ans.2. Mandibular

USMLE Case Scenario

Annular pancreas is a condition that results when normal pancreatic tissue completely or partially encircles the duodenum. Annular pancreas is thought to arise from failure of normal clockwise rotation of the ventral pancreatic bud. In children, there is a common association with other serious congenital anomalies such as intracardiac defects, Down’s syndrome, and intestinal malrotation. It commonly encircles:

First part of duodenum
Second part of duodenum
Third part of duodenum
Fourth part of duodenum
Jujenum
Ileum

Ans.2. Second part of duodenum

USMLE Case Scenario

Pancreas is a mixed gland divided into four portions: the head, the neck, the body, and the tail. It is a retroperitoneal organ. The structure related to the head of the pancreas is:

Hilum of spleen
Uncinate process
Portal vein
Tuber omentale
Pappilary process
Foramen of Winslow
Ligament of Treitz
Linea semilunaris

Ans.2. Uncinate process

USMLE Case Scenario

The Distal portion of the gallbladder has the appearance of a diverticulum, which is called:

Morrisons pouch
Zenkers diverticulum
Meckel’s diverticulum
Spiral valve of Heister
Hartmann’s pouch
Uncinate process
Tuber omentale
Pappilary process
Foramen of Winslow

Ans.5. Hartmann’s pouch

USMLE Case Scenario

Pancreas is a mixed gland divided into four portions: the head, the neck, the body, and the tail. It is a retroperitoneal organ. The endocrine portion of pancreatic function is served by the structures termed the islets of Langerhans. The islets are nearly spherical collections of cells scattered throughout the pancreatic parenchyma and is composed of several distinctive cell types. True statement is:

The insulin-producing alpha cells compose the majority of the islet population
111The insulin-producing beta cells compose the minority of the islet population
The insulin-producing beta cells compose the majority of the islet population
The insulin-producing alpha cells compose the minority of the islet population

Ans.3. The insulin-producing beta cells compose the majority of the islet population

USMLE Case Scenario

Embryologically, the gut rotates and the rotation occurs in a way that:

The large intestine rotates in a clockwise manner around the axis of the celiac trunk
The large intestine rotates in a clockwise manner around the axis of the superior mesenteric artery
The large intestine rotates in a clockwise manner around the axis of the inferior mesenteric artery
The large intestine rotates in a counterclockwise manner around the axis of the celiac trunk
The large intestine rotates in a counterclockwise manner around the axis of the superior mesenteric artery
The large intestine rotates in a counterclockwise manner around the axis of the inferior mesenteric artery

Ans.5. The large intestine rotates in a counterclockwise manner around the axis of the superior mesenteric artery

USMLE Case Scenario

The ligaments that should be carefully considered during mobilization of the splenic flexure to avoid injury to the spleen are:

Leinorenal and splenocolic attachments
Phrenocolic and leinorenal attachments
Phrenocolic and splenocolic attachments
Greater omentum and splenocolic attachments
Lesser omentum and leinorenal attachments

Ans.3. Phrenocolic and splenocolic attachments

The large intestine rotates in a counterclockwise manner around the axis of the superior mesenteric artery

USMLE Case Scenario

The anastomosis between the superior and inferior mesenteric vessels is known as the:

Marginal artery of Drumond
Sudecks point
Batesons Plexus
Vasa recta
Anastomosis of Riolan

Ans.5. Anastomosis of Riolan

USMLE Case Scenario

As Per the anatomical knowledge of a student, which is not true about pain:

A sudden burning pain in the epigastric region suggests a perforated viscus
Severe intermittent cramping pain with short pain-free intervals favors small bowel obstruction
Sudden excruciating tearing pain maybe associated with a ruptured aneurysm
Pain of acute cholecystitis frequently radiates around the right costal margin to the right scapula and to the shoulder
Pain in acute pancreatitis is usually epigastric in origin, with subsequent radiation along both costal margins to the back
Ureteral calculi causes pain radiating to the groin
Pain of stomach is referred to perineum

Ans.7. Pain of stomach is referred to perineum

USMLE Case Scenario

Maximal tenderness in the right lower quadrant over Mcburney’s point is suggestive of an inflammation of an organ. The characteristic feature of the organ implicated is:

It is rich in blood supply with rich anastomosis
112It is not covered by peritoneum
It is rich in lymphatic tissue
It is a derivative of foregut
It has a fixed location
It has a wide lumen

Ans.3. It is rich in lymphatic tissue

USMLE Case Scenario

The arterial supply to the hypothalamic-pituitary region is complex and arises from three sources. The inferior hypophyseal artery, the superior hypophyseal arteries and the middle hypophyseal arteries. These vessels drain into the hypophyseal portal system, which forms a secondary venous plexus in the anterior pituitary and ultimately empties into the cavernous sinus. The inferior hypophyseal artery is:

A branch of the internal carotid artery
A branch of the external carotid artery
A branch of the common carotid artery
A branch of the vertebral artery
A branch of the subclavian artery

Ans.1. A branch of the internal carotid artery

USMLE Case Scenario

Oxyphil cells are a feature of:

Spleen
Pituitary
Adrenals
Prostate
Lens of eye
Cochlea
Thymus
Thyroid
Parathyroid

Ans.9. Parathyroid

USMLE Case Scenario

The superior parathyroid glands are usually located on the posterior surface of the upper portion of the thyroid lobe. The lower parathyroid glands are more ventral, close to the lower pole of the thyroid gland. True statement about the development of parathyroids is:

The superior parathyroids arise from the second pharyngeal pouch and the inferior parathyroids arise from the third pharyngeal pouch
The superior parathyroids arise from the second pharyngeal pouch and the inferior parathyroids arise from the fourth pharyngeal pouch
The superior parathyroids arise from the third pharyngeal pouch and the inferior parathyroids arise from the fourth pharyngeal pouch
The superior parathyroids arise from the fourth pharyngeal pouch and the inferior parathyroids arise from the third pharyngeal pouch

Ans.4. The superior parathyroids arise from the fourth pharyngeal pouch and the inferior parathyroids arise from the third pharyngeal pouch

USMLE Case Scenario

The transition between the oblique fibers of the thyropharyngeus muscle and the transverse fibers of the cricopharyngeus muscle creates a point of potential weakness in the pharyngoesophageal segment, which is the site of origin of:

Rathkes pouch
113Foramen of morgagni
Pharyngoesophageal diverticulum
Laryngocele

Ans.3. Pharyngoesophageal diverticulum

USMLE Case Scenario

The esophagus is a hollow tube of muscle that is approximately 25 cm in length and extends from the pharynx to the stomach. It is arbitrarily divided into four segments: pharyngoesophageal, cervical, thoracic, and abdominal.

True statement about esophagus is that:

The esophagus is a nonmucosal-lined muscular tube that has a serosa
The esophagus is a nonmucosal-lined muscular tube that lacks a serosa
The esophagus is a mucosal-lined muscular tube that has a serosa
The esophagus is a mucosal-lined muscular tube that lacks a serosa

Ans.4. The esophagus is a mucosal-lined muscular tube that lacks a serosa

USMLE Case Scenario

Throughout the fat of the breast, coursing from the overlying skin to the underlying deep fascia, strands of dense connective tissue provide shape and hold the breast upward. These strands, devoid of epithelial elements, are called:

Montogmerys tubercles
Sappys Plexus
Axillary tail of spence
Cooper’s ligaments
Milk line
Pectoral fascia

Ans.4. Cooper’s ligaments

USMLE Case Scenario

Retropubic space is named after:

Fallopius
Meckel
Camillo golgi
Hunter
Scarpa
Retzius
Tredlenburg

Ans.6. Retzius

USMLE Case Scenario

In the cochlear pathway, the axons terminate in the dorsal and ventral cochlear nuclei in the medulla and the pathway to the auditory cortex consists of at least four orders of neurons and includes the superior olivary complexes, the lateral lemnisci, the inferior colliculi, and the medial geniculate bodies. The auditory cortex:

Lies in the posterior portion of the Inferior temporal gyrus
Lies in the posterior portion of the superior temporal gyrus
Lies in the posterior portion of the superior frontal gyrus
Lies in the posterior portion of the middle frontal gyrus
Lies in the posterior portion of the inferior frontal gyrus

Ans.2. Lies in the posterior portion of the superior temporal gyrus

USMLE Case Scenario

The primordia of the principal respiratory organs appear as a medial longitudinal groove in the ventral wall of the pharynx by the fourth week of gestation. True statement is:

The tube is lined with ectoderm, from which the epithelium of the respiratory tract develops
The tube is lined with mesoderm, from which the epithelium of the respiratory tract develops
The tube is lined with endoderm, from which the epithelium of the respiratory tract develops
The tube is lined with endothelium, from which the epithelium of the respiratory tract develops
The tube is lined with mesothelium, from which the epithelium of the respiratory tract develops

Ans.3. The tube is lined with endoderm, from which the epithelium of the respiratory tract develops

USMLE Case Scenario

Folds of serous pericardium surrounding the entrance of the right and left pulmonary veins are connected by an irregular pericardial reflection that creates a space called as:

Transverse sinus
Oblique sinus
Occipital sinus
Maxillary sinus
Coronary sinus
Sinus of morgagni
Sinus venosus

Ans.2. Oblique sinus

USMLE Case Scenario

The Mullerian ducts develop into the:

Ovaries, uterus, cervix, and lower vagina
Ovaries, uterus, cervix, and upper vagina
Cervix, and upper vagina only
Uterus, cervix, and upper vagina
Fallopian tubes, uterus, cervix, and upper vagina
Ovaries, fallopian tubes, uterus, cervix, and upper vagina

Ans.5. Fallopian tubes, uterus, cervix, and upper vagina

USMLE Case Scenario

A semicircular line which is about halfway between the umbilicus and pubic symphysis is named as line of:

Mc Burney
Nelaton
Rion
Douglas
Waldeyer
Morrison
Heister
Scarpa
Zuckderkand

Ans.4. Douglas

USMLE Case Scenario

Lymphatics from the gallbladder drain into the lymph node, located near the superior aspect of the junction of the infundibulum of the gallbladder and the cystic duct. It is known as:

Lymph node of Rossenmüller
Lymph node of Cloquet
Delphic node
Lymph node of lund

Ans.4. Lymph node of lund

Chapter Notes

Anatomy1

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

MENISCAL TEAR

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario

USMLE Case Scenario