Textbook of Anatomy for Nurses (for BSc Students) PR Ashalatha
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1General Anatomy
CHAPTER
❏ Introduction to Anatomy
❏ Primary Tissues
❏ Special Connective Tissues
❏ Nervous Tissue
❏ Muscle Tissue
❏ Lymphoid Tissue
❏ Skin and its Appendages2

Introduction to AnatomyCHAPTER 1

 
INTRODUCTION
Anatomy is the study of structure and function of the body. Aristotle (384-322 BC) was the first person to use the term “anatome”, a Greek word meaning “cutting up or taking apart” The Latin word “dissecare” has a similar meaning.
Anatomy is one of the oldest basic medical sciences; it was first studied formally in Egypt. Human Anatomy was taught in Greece by Hippocrates (460-377 BC) who is regarded as the “Father of Medicine”. He has written several books on Anatomy.
 
MEDICAL AND ANATOMICAL TERMINOLOGY
Although students entering the new world of Medicine are familiar with the common terms for many parts and regions of the body (e.g. heart, brain, liver, lung), they should learn to use the internationally adopted nomenclature, the Nomina Anatomica.
Anatomical terminology is important because it introduces the student to a large part of Medical Terminology. Since most terms are derived from Latin and Greek, medical language can be difficult at first, but as the student learns the origin of medical terms, the words make sense.
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Clear communication is fundamental in Clinical Medicine. To describe the body clearly and to indicate the position of its parts and organs relative to each other, Anatomists and Clinicians use the same descriptive terms of position and direction.
 
The Anatomical Position (Fig. 1.1)
All descriptions in Human Anatomy and Clinical Medicine are expressed in relation to “Anatomical Position”.
A person in the anatomical position is standing erect (or lying supine) with the head, eyes and toes directed forward, the upper limbs by the sides with the palms facing anteriorly. The student must always visualize the anatomical position in his “mind's eye” when describing patients lying on their backs, sides or fronts. Always describe the body as if it were in the anatomical position.4
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Fig 1.1: Anatomical position
 
The Anatomical Planes
Anatomical descriptions are also based on four imaginary planes that pass through the body in the anatomical position. They are as follows:
  1. Median
  2. Sagittal
  3. Coronal
  4. Horizontal
 
The Median Plane (Fig. 1.2)
This is the imaginary vertical plane passing longitudinally through the body from front to back, dividing it into right and left halves.
 
The Sagittal Planes
These are parallel to the median plane. They are named after the sagittal suture of the skull (Fig. 1.3). The sagittal plane that passes through the median plane can be called the midsagittal plane; those passing parallel to the midsagittal plane and away from the median plane may be called the parasagittal planes.
 
The Coronal Planes
These are imaginary vertical planes passing through the body at right angles to the median plane, dividing it into anterior (front) and posterior (back) portions. These planes are named after the coronal suture of the skull, which is in a coronal plane (Fig. 1.3).
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Fig 1.2: Median plane
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Fig 1.3: Skull—viewed from above, showing sagittal and coronal sutures
 
The Horizontal Planes
These are imaginary planes passing through the body at right angles to both the median and coronal planes (They are parallel to the “horizon”). A horizontal plane divides the body into superior (upper) and inferior (lower) parts. A horizontal plane is also referred to as the transverse plane (Fig. 1.4).5
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Fig 1.4: Horizontal or transverse plane
 
TERMS
 
Terms of Relationship (Table 1.1)
Various terms (adjectives) are used to describe the relationship of parts of the body in the Anatomical Position.
 
Terms of Movement (Fig. 1.5, Table 1.2)
Various terms are used to describe the different movements of the limbs and other parts of the body. Movements take place at joints where two or more bones meet or articulate with one another.
 
The Meaning of Terms
Most of the anatomical terms are derived from Greek and Latin. Some of them are translated to English (e.g. musculus = muscle). Many anatomical terms indicate the shape, size, location and function or resemblance of a structure to something.
 
Examples
  1. According to shape
    1. Deltoid — delta or triangular
    2. Sphenoid — wedge-shaped
    3. Styloid — pillar-shaped
    4. Uvula — grape-like
    5. Pisiform — Pea-shaped
  2. According to the number of heads of origin
    1. Biceps — 2 heads
    2. Triceps — 3 heads
    3. Quadriceps — 4 heads
      Table 1.1   Commonly used terms of relationship and comparision
      No.
      Term
      Meaning
      Example
      1.
      Superior (cranial)
      Nearer to the head
      The lung is superior to the diaphragm
      2.
      Inferior (caudal)
      Nearer to the feet (tail)
      The stomach is inferior to the heart
      3.
      Anterior(ventral)
      Nearer to the front
      Cornea is anterior to the lens
      4.
      Posterior(dorsal)
      Nearer to the back
      Lens is posterior to the cornea
      5.
      Medial
      Nearer to the median plane
      Heart is medial to the lung
      6.
      Lateral
      Away from the median plane
      Kidney is lateral to the vertebral column
      7.
      Proximal
      Nearer to the trunk or point of origin
      The knee is proximal to the ankle
      8.
      Distal
      Farther from the trunk or away from the origin
      The wrist is distal to the elbow
      9.
      Superficial
      Nearer to the surface
      Muscles of the thigh are superficial to the bone femur
      10.
      Deep
      Farther from the surface
      The femur is deep to the muscles of thigh
      11.
      External (outer)
      Towards the exterior
      The sclera is the external coat of the eyeball
      12.
      Internal (inner)
      Towards or in the interior
      Retina is internal to the sclera and choroid
      13.
      Central
      Nearer or toward the center
      Brain is a part of the central nervous system
      14.
      Peripheral
      Farther or away from the center
      The spinal nerves are part of the peripheral nervous system
      15.
      Parietal
      Pertaining to the external wall of a body cavity
      Parietal peritoneum lines the abdominal wall
      16.
      Visceral
      Pertaining to the covering of an organ
      Visceral pleura covers the external surface of lung
      6
      Table 1.2   Commonly used terms of movement
      No.
      Term
      Meaning
      Example
      1.
      Flexion
      Bending or decreasing the angle between body parts
      Flexing the elbow joint
      2.
      Extension
      Straightening or increasing the angle between body parts
      Extending the knee joint
      3.
      Abduction
      Moving away from the median plane
      Abducting the upper limb
      4.
      Adduction
      Moving toward the median plane
      Adducting the lower limb
      5.
      Rotation
      Moving around the long axis
      Medial and lateral rotation of UL
      6.
      Circumduction
      Circular movement combining flexion, extension,
      Circumduction of upper limb abduction and adduction e.g. bowling
      7.
      Eversion
      Moving the sole of the foot away from the median plane
      8.
      Inversion
      Moving the sole of the foot toward the median plane
      e.g. As if to remove the thorn
      9.
      Supination
      Rotating the forearm and hand laterally, palm faces anteriorly
      e.g. When a person extends a hand to beg
      Radius lies parallel to ulna
      10.
      Pronation
      Rotating the forearm and hand medially so that palm faces posteriorly. Radius crosses ulna diagonally
      e.g. Patting a child on the head
      11.
      Protrusion
      Moving anteriorly
      Sticking the chin out
      12.
      Retrusion or retraction
      Moving posteriorly
      Tucking the chin
      13.
      Elevation
      To lift
      Elevation of eyeball to look upwards
      14.
      Depression
      To lower
      Depression of eyeball to look at the feet
  3. According to function
    For example,
    1. Depressor anguli oris — Muscle which depres;ses the angle of mouth
    2. Tensor tympani — Muscle which tenses the tympanic membrane
  4. According to size
    1. Gluteus maximus — Largest among the gluteus muscles
    2. Gluteus minimus — Smallest among the gluteus muscles
  5. According to length
    1. Abductor pollicis longus — Long abductor of thumb
    2. Abductor pollicis brevis — Short abductor of thumb
  6. According to consistency
    Pancreas — Pan = throughout; Kreas = Flesh; fleshy throughout
    Dura mater — Dura = tough; Mater = mother; Tough mother
  7. According to location
    1. Biceps brachii — Biceps muscle of arm
    2. Biceps femoris — Biceps muscle of thigh
    3. Triceps suri — 3 muscles of calf
  8. According to sites of attachment
    For example,
    1. Sternocleidomastoid muscle — attached to sternum, clavicle and mastoid
    2. Omohyoid; omos = shoulder
      Omohyoid — from scapula (shoulder blade) to hyoid.
Some of the commonly used anatomical and clinical abbreviations are given in Table 1.3.
 
APPROACHES IN STUDYING ANATOMY
The three main approaches are as follows:
  1. Regional Anatomy
  2. Systemic Anatomy
  3. Clinical Anatomy
 
Regional Anatomy or Topographical Anatomy
It is the study of the body by regions such as head, neck, thorax, abdomen and limbs.
 
Systemic Anatomy (Table 1.4)
It is the study of the body systems, e.g. digestive system, cardiovascular system, nervous system.7
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Fig 1.5: Movements
 
Clinical Anatomy
Correlation of anatomy with clinical signs and symp;toms to arrive at a diagnosis.
 
Gross Anatomy and Histology
 
Gross Anatomy
It is the examination of body structures that can be seen without a microscope.
 
Histology
Microscopic study of a tissue.
Table 1.3   Commonly used anatomical and clinical abbreviations
a, aa
Artery, arteries
ANS
Autonomic nervous system
A-V
Atrioventricular
C1-C7 (C8)
First to seventh cervical vertebrae or 1st to 8th spinal nerves
Ca
Cancer, carcinoma
CAD
Coronary artery disease
CAT or CT
Computerized axial tomography
CN
Cranial nerve
CNS
Central nervous system
CSF
Cerebrospinal fluid
ECG
Electrocardiogram
EEG
Electroencephalogram/graphy
G; GK
Greek
GI / GIT
Gastrointestinal/gastrointestinal tract
IP
Interphalangeal
IV
Interventricular or intervertebral
IV
Intravenous
IVC
Inferior vena cava
IVF
In vitro fertilization
Jt
Joint
L1 — L5
1st to 5th Lumbar Nerves/vertebrae
LA
Left atrium
LICS
Left Intercostal space
Lig
Ligament
LP
Lumbar puncture
LV
Left ventricle
m, mm
Muscle, muscles
MCP
Metacarpophalangeal
MI
Myocardial Infarction
MRI
Magnetic resonance imaging
MTP
Medical Termination of Pregnancy
MV
Mitral valve
n, nn
Nerve, nerves
PA
Posteroanterior
PNS
Peripheral nervous system, paranasal sinuses
RA
Right atrium
RV
Right ventricle
S1-S5
First to fifth sacral vertebrae/nerves
SA
Sinuatrial/sinoatrial
SVC
Superior vena cava
T1 — T12
1st to 12th thoracic vertebrae/nerves
TIA
Transient ischemic attack
TMJ
Temporomandibular joint
V, VV
Vein/veins
8
Table 1.4   Systems and their branches of study
No.
System
Organ/Organs studied
Branch of study
1.
Integumentary system
Skin
Dermatology
2.
The skeletal system
Bones and cartilages
Osteology
3.
The articular system
Joints and ligaments
Arthrology
4.
The muscular system
Muscles
Myology
5.
The nervous system
Central and peripheral nervous system
Neurology
6.
The circulatory system/cardiovascular system
Heart, blood vessels and lymphatics
Angiology/Cardiology
7.
The digestive system
Digestive tract and glands assisting digestion
Gastroenterology
8.
The respiratory system
Air passages and lungs
Pulmonology
9.
The urinary system
Kidneys, ureters, bladder and urethra
Urology
10.
The reproductive or genital system
Genital organs—male or female
Female — Gynecology Male — Andrology
11.
The endocrine system
Ductless glands, e.g. Thyroid, pituitary
Endocrinology
 
Anatomical Variations
Individuals differ in physical appearance. Similarly variations are seen in the size, shape, weight, origin, course and termination of various organs, arteries, nerves and veins. So, individual variation must be considered while examining a patient and in the diagnosis and treatment of that patient.