Techniques in Histopathology and Cytopathology Sadhana Vishwakarma
Page numbers followed by f refer to figure and t refer to table.
powder 81
stones 81
Absolute alcohol 106, 108, 147
Absolute ethyl alcohol 147
Acetic acid 45, 178
Acetone 58, 59
alcohol 20
concentration of 55
fast bacteria 120, 126
fast staining 120
fuchsin 105
phosphatase 126
staining for 117
thionin method 152
Acidic stains 102
Acidified ethanol solution 122
Acidified toluidine blue method 119
Acridine orange 105
fluorescence method 153
Acrolein 46
Acrylic resins 74
Adhesive, types of 83
Adipocytes 8
Adipose 181
connective tissue 9f
tissue 8
Aerosol sprays 95
Affinity 101
Agar 68
Agar-ester wax double infiltration 74
Agar-paraffin wax double embedding 74
chelating 54
clearing 60, 182
decalcifying 51, 53
dehydrating 58
Agitation 55
Agranulocytes 12
Albumen 83, 84
Alcian blue 36, 105
Alcohol 58
descending grades of 107
Alcoholic pinacyanide 124
Aldehydes 42
Alizarin red 105
Alkaline phosphatase 116, 125
Alpha-naphthol 117
Alternative embedding media 68
Alum hematoxylins 108
Alumina 81
hematoxylin 108
oxide 81
Ammonium hydroxide 177
Amphoteric 181
stains 102
Amyl acetate 61
Amyloid 104, 124
Anabolism 5
Anaphase 3, 5
Anaphylactic 119
Anaplasia 181
Anesthesia 181
Anhydrous 177
Aniline blue 105
Anoxia 181
Antibody 172, 181
primary 173
secondary 173
Antigen 181
retrieval 173
Apathy's medium 131
Aperture iris diaphragm 18
Aqueous ammonia 178
Aqueous media 68
Araldite embedding solution 74
Areolar connective tissue 8, 8f
Argentaffin 181
Artefact 47, 114, 181
Arthroscopy 170
Artificial exfoliation 135
applications 135
Artists’ grade pigments 36
Aspiration procedure 143
Auramine O 105
Autopsy 33, 34, 38
clinical 34
Autoradiography 171
method 171
steps of 172f
Auxochrome 102, 181
Axolemma 14
Axon 14
Axoplasm 14
Ayre's spatula 139f
Azo dye 102
coupling method 116, 117
Azocarmine G 105
Bacteria 119, 126
Bacterial decomposition 40
Barr bodies 151
Basal cells 136
Basophils 12
Belgian stones
blue 82
yellow 82
Benzene 60
Benzidine method 117
Benzoquinone 46
Bevel 181
Biebrich scarlet 105
Bile pigments 115, 125
Bilirubin 181
Biogenic amines 47
Biopsy 32, 33, 48, 181
core 33
curettings 51
excisional 34
incisional 34
open 34
small 51
stereotactic needle 33
testicular 48
Birefringence 29
Bismarck brown 105
Block holders 85f
Block to block holder, mounting of 85
Blood 11
analyze 38
cells, types of 11f
films 153
vessels 119
Body tube 19
Bone 10, 51
compact 11
cross-section of 11f
forming cells 11
marrow 48, 96, 182
spongy 11, 11f
Borrelia recurrentis 121
Bouin's solution 45
Brain 96
fixation of 157
Breast 96
cyst aspiration 142
secretions 142
Bronchial brushings 142
Bronchial washings 142
Bronchoscopy 170
Broom like device 139
Buccal smear 152
Buffer solutions 177
covering range 178t
Buffered neutral formalin 44
Calcite crystals 30
Calliphoridae 33
Cambridge rocking microtome 78f
Canada balsam 130
Canaliculi 11
Cancer 182
Candida 126
Carbohydrate 112, 125
catabolism 6
Carbol fuchsin 120
Carbon dioxide gas 95
Carborandum 81
Carbowax 68, 147
Carcinogen 182
Carcinoma 136f
Cardiac muscle 13, 14f
Carnoy's fixative 147
Carnoy's fluid 45
composition of 45
Cartilage 10
Catabolism 6
Catalogue 182
Cedar wood oil 61
Cell 1
division 2
during malignancy 135
intermediate 137
membrane 1
metabolism 5
of normal genital track 136f
structure of 1, 1f
Celloidin 69, 72, 182
Cellosolve 59
Cells, superficial 137
Cellular abnormalities 136f
Cellular pathology 32
Cellulose 83, 84
nitrate 68, 69
Centrosomes 2
Cerebrospinal fluid 38, 141
Cervex brush 139f
device 139
Cervical material 140f
Cervical/vaginal smear, collection of 139
Cervix 96
visualization of 138
Champy's fluid 45
Chemical classification of dye 103t
Chemical hazards 161
Chemical oxidation 107
Chemical pathology 32
Chemical production 103
Chemical storage 161
Chemical waste disposal 161
Chiasma, singular 5
Chloroform 61, 63
Chrome deposits 114
oxide 81
trioxide 57
Chromogen 102, 173
Chromophore 182
Chromyl chloride 46
Chylous 182
Cilia 182
Ciliated columnar cells 137
Ciliated epithelium 7, 7f
Citrate-citric acid buffer 54
Citric acid 178
Clove oil 61
Coagulant 182
Coating fixatives 147
Cold microtome 79
Cole's hematoxylin 108
composition of 109
Collagenous 182
Colloidal 182
Colonoscopy 170
Colposcopy 170, 170f
purpose of 170
Columnar cells 137
Columnar endometrial cells 137
Columnar epithelium 7, 7f
Common sense 160
Compound fixatives 42, 44
Condenser 18
focus knob 19
Confocal microscope 29f
Confocal scanning optical microscopy 28
Connective tissue 8, 96, 104, 110, 125
Coplin jar 107f, 144
Coulombic attractions 100
Counter stains 109, 109t, 173
Covalent bonds 101
Coverslipping 173
Coverslips 133
Cresyl fast violet method 152
Crohn's disease 119
Cryoelectron microscopy, development of 27
Cryofixation 27
Cryogen selection 94
Cryoprotectants 94
Cryostat 79, 93, 97, 98f
advantages of 98
disadvantages of 98
fixation of 98
procedure 98
Cryo-tissue microarrays 174
Crystal violet 105
stain 120
Cuboidal epithelium 6, 6f
Cutaneous lesions, multiple 119
Cystoscopy 170
Cytobrush 139, 139f
Cytochrome oxidase catalyses 117
Cytogenetic study 48
Cytokinesis 3, 5
Cytological changes 135
Cytological fixatives 42, 45
Cytological specimens 144
Cytological staining techniques 148
Cytology 136, 162
Cytopathology 135
advances in 165
Cytoplasm 2
Cytoplasmic changes in cancer 136
Cytoplasmic fixatives 42, 45
Cytoplasmic inclusions 2
Cytoplasmic reticulum 2
Cytoplasmic stains 109
Dark field illumination, reflected 23
Decalcification 51, 163
technique of 51
treatment after 54
Decolorizer 120
Deconvolution microscopy 29
Dehydrating fluids 58
Dehydration 27, 58, 107, 110, 182
completion of 59, 60f
precaution during 59
Dehydrogenase 126
demonstration of 118
Denaturation 182
Denatured alcohol 58, 146
Dendrites 14
Deparaffinization 110, 172, 182
Diacetyl 46
Diamond 81
knives 80
Dichromate, fixatives containing 57
Diethyl pyrocarbonate 46
Diethylene dioxide 59
Dimethyl sulfoxide 69
Dimethyl-para-phenylenediamine 117
Dimmock embedding mould 70f
Dioxane 58, 59
Disinfectants 161
Disodium salt 177
Disposable blades 80
Disposable plastic pipette 140f
Distilled water 108, 147
Distrene 130
Draw tube 19
Dunn Thompson method 114
Dyes, types of 101
Ebner's fluid 53
Efferent neurons 14
Ehrlich's hematoxylins 108
composition of 108
Elastic cartilage 10
connective tissue 10f
Elastic connective tissue 9, 10f
Elastic fibers 125
Electric cryobath–isopentane 95
Electrolytic decalcifications 54
Electron microscope
reflection 27
types of 26
Electron microscopy 25
Elftmann's fluid, composition of 46
Embedding 67
media 68, 69
moulds 70f
Endocervical brush 139, 139f
Endocervix 137
Endogenous peroxide quenching 173
Endogenous pigments 114
Endometrial aspiration 140
Endometrial cells 137
stromal 137
Endoplasmic reticulum 2
Endoscope 169f
Endoscopic biopsy 170
Endoscopy 169
purpose of 170
specimens 142
types of 170
Enzymes 5, 47
staining of 116
Eosin 37, 109
azure 148
procedure 123
staining 123
method 110
Eosinophils 12
mucins 104
tissues 6
keratinized stratified 7
simple 6
Epoxy resins 74
Equipment hazards 162
electrical 162
mechanical 162
Equipment required for section cutting 83
Erythrocytes 11
Erythrosin 37
Esophagus 142
Ester wax 68, 69
Ethanol 46, 58
Ether alcohol mixture 146
Ethoxyethanol 59
Ethyl alcohol 43, 58, 146, 147
Ethylene glycol monoethyl ether 59
Euparal 130
Evaporation rate 41
Exfoliate 135
Exfoliation, types of 135
Exfoliative cytology 135
Exogenous pigments 114
Eyepiece 19
adjust 22
tube 19
Farrant's medium 131
Fat catabolism 6
Femur 10
Ferric chloride solution 111
Fetal maturity 141
Fibro cartilage 10
Fibroblasts 8
Fibrocartilage connective tissue 10f
Fibrocyte 183
Fibrosis 183
Fibrous, white 9
Fick's law 57
Filter holder 18
Fine focus knob 19
Fine-needle aspiration 34
cytology 142
technique of 143f
Fire hazards 161
First aid action 163
Fission 183
Fixation before processing, completion of 57
Fixation, duration of 41, 48
concentration of 41
functions of 40
properties of 40
simple 42
special purpose 147
types of 41
volume of 48
Fleming's fluid 45
composition of 45
Floating water bath 83
Flow cytometry study 48
abdominal 135
amniotic 141
transfer processor 65, 65f, 65t
Fluorescence microscope, components of 25f
Fluorescence microscopy 24
Fluorescent 183
antibody technique 25, 26f
protein, green 25
staining 104
Fluorochrome 25
Fluorochroming 25f
Forensic autopsy 34
Formaldehyde 42, 46
Formalin pigment 114
removal of 44
Formic acid 53
solution 53
Freeze-etch 27
Freeze-fracture 27
Freezing, theory of 93
Frozen section 37, 48, 93
advantages 93
applications 93
disadvantages 93
mounting of 96
staining of 123
storage of 97
technique 163
Frozen tissue, storage of 97
Fructose 20
Fungi 121, 183
Gastric washings 135
Gastroscopy 170
Gelatin 68, 83, 84
embedding 72
Gendre's fluid 46
composition of 46
Genital tract, normal 136
Germinal cells 136
Giemsa 105
Giemsa's stains 121, 144, 153
Glacial acetic acid 108, 147, 177
Glass knives 80
Glass slide 35
Glutaraldehyde 43, 46
Glycerin jelly 131
Glycerol 130, 131
Glycogen 2, 46
Glycol ethers 59
Gmelin's method 115
Golgi apparatus 2
Gram's iodine 120
Gram's stain 119
Gram-negative bacteria 120
Gram-positive bacteria 119, 120
Granules, secretion 2
Granulocytes 12
Grocott's silver methanamine method 123
Gut 96
Gynecological sample collection 138
Hemoglobin, staining of 114
Hage-Fontana silver 121
method 121
Hand microtome 79
Hardening effect of fixative 48
Harri's hematoxylin 108, 126, 148
composition of 108
Haversian canal 11
Haversian systems 11
Heart 96
fixation of 157
Heidenhain susa fixative 44
Heidenhain's hematoxylin 109
Helly's fluid 44
Hematoxylin 105, 123, 108
procedure 123
solution 109, 110
stains 107
standard 110
Hemoglobin 125
Hemosiderin 115
pigments 125
Histopathology 32
advances in 165
laboratory, safety in 160
Histotechnicians 38
Hollow viscera, fixation of 157
Honing 82
technique of 82, 82f
Hormonal assessment, stains for 150
Hormone receptor assays 48
Hot plate 83
method 89f
Humerus 10
Hyaline cartilage 10, 10f
Hydration 110
Hydrocarbon slurry 95
Hydrochloric acid 177, 178
Hydrogen bonding 101
Hydrophilic media 129
Hydrophilic mountants 130
disadvantages of 129
bonding 100
media 69
mountants 130
Hydrous 177
Hyperplasia 183
Hypersensitivity 183
Hypertonic solution 183
Hypotonic solution 183
Hysterectomy 183
Ice crystal artefact 98
Immersion oil 19
Immunofluorescence 25
Immunohistochemistry 172
applications of 172
Impregnation oven 62, 62f
Impression smear preparations 37
Indigo-carmine 105
Infectious hazards 160
Infiltrating media 96
Inhibisol 61
Interstitial lamellae 11
Ion beam milling 27
Ion exchange resins 54
Iris diaphragm 18f
Iron hematoxylins 108
Isopentane 94
Isopropanol 146
Isopropyl alcohol 58, 59
Istochemical fixatives 42
Jars, staining 107f
Joint fluid 141
Kaiser's glycerin jelly 131
Kaiserling's fixative 157
Kaiserling's method 157
Kaiserling's solution 157
Karo corn syrup 131
Karyopyknotic index 151
Ketones 59
Kidney 96
Knife 80f
adjustments 86
back 80f
edge 82
handle 80, 80f
sapphire 80
sharpening 81, 82
sharpner, automatic 168, 168f
steel 80
Lactic acid orcein technique 152
Lacunae 11
Laparoscopy 170
Laryngoscopy 170
Larynx 142
Lead hematoxylins 108
Leishman stain 144
Leishmania 123
Lens 22
systems 19
Lesion, immobilization of 143
Leuckhard embedding boxes 70
Leuko dyes, colorless 102
Leukocytes 11
Levulose syrup 131
Limb 20
fixation of 157
Lip 96
Lipid 2, 46, 112, 125
stains for 152
based preparations 35
connective tissue 11
nitrogen 94
Liver 96
biopsies 48
Lubricants, types of 81
Lung 96
Lymph 12, 12f
Lymph node 48, 96
Lymphocytes 12
Lysochromes 103
Lysosome 2
Macrophages 8
Magnesium oxide 81
Masson-Fontana ammonical silver reaction 115
Mast cell 8, 119
demonstration of 119
granules 104
Maturation index 151
Mayer's glycerol albumen 84
Mayer's hemalum 116, 126
Mayer's hematoxylin 108, 126
composition of 108
Meiosis 3, 5, 184
stages of 4f
Melanin 115, 184
pigments 125
Membrane 30, 184
filters 146
Mercuric chloride 43, 147
Mercuric oxide 108
Mercuric pigments 114
removal of 45
Metabolism 184
Metachromatic staining 104
Metal boat mould 70f
Metallic impregnation 104
Metaphase 3, 5
Methacrylates 74
Methanol 58, 146
Methenamine silver nitrate method 121
alcohol 43
benzoate 61
green 106
salicylate 61
violet 124
Methylated spirit 58
Methylene blue 106, 126
wet film technique 150
Microanatomical fixatives 42, 44
Microorganisms, staining of 119
Microphages 12
slides, cleaning of 20
care of 20
compound 21
parts of 18, 20f
bright field 21, 21f, 22
Microscopy 17
advantages of dark field 23
applications of phase contrast 24
basic terminology in 17
dark field 22, 23, 23f
types of 21
Microtome 77, 79, 86
base sledge 78, 78f
freezing 78, 95, 95f
knife 79
care of 81
profiles 79, 79f
types of 80
parts of rotary 77f
rocking 78
setting 84
sliding 78, 78f
vibrating 79
Microtomy 77, 163
fixation 165
irradiation 165
tissue processing 166f, 167
processing 167t
tissue processing 166
Mineral acids, dilute 53
Mitochondria 2
Mitochondrion, structure of 2f
Mitosis 3
stages of 3f
Molar solution 176, 177t
Molybdenum hematoxylins 108
Monocytes 12
Mononuclear leukocytes 12
Mordant staining 104
Motor neurons 14
Moulds for embedding 70
Mount specimen 21
Mountant, types of 129
Mounting of block 85f
Mounting sections, methods of 131
Mounting, techniques of 132f
Mucin 2
Mucocele fluid 144
Muco-substances 46
content 144
low 144
Multi-tumors tissue microarrays 174
Muscle 96
biopsies 48
Muscular tissues 12
safety in 159
techniques 156
basic 156
Mycobacterium 120
leprae 120
tuberculosis 120
Myelin 14
Myelinated fibers 14
Myofibrils 12
Nadi’ reaction 117
Nasopharynx 142
Natural dyes 101
Natural exfoliation 135
Natural oxidation 107
Necropsy 34
Needle 143
biopsy 33
Nerve 119
biopsies 48
cell 14, 14f
Nervous tissues 13
Neurilemma 14
Neuroglia 13
Neuron 13, 14
afferent 14
types of 14
Neutral EDTA solution 54
Neutral stains 102
Neutrophils 12
Nipple discharge 142
Nitric acid 53, 177
solution 53
Nitro dyes 102
Nocardia 120
asteroids 120
brasiliensis 120
Non-ciliated endometrial cells 137
Non-corrosive knives for cryostats 80
Non-gynecological sample collection 140
Non-keratinized stratified epithelium 7
Non-myelinated fibers 14
changes in cancer 136
fixatives 42, 45
stains 109
Nucleic acid 5, 47
stains for 153
Nucleoplasm 2
Nucleoproteins 47
Nucleus 2
Numerical aperture 17
Numerous dehydrating agents 58
Oil red method 152
Omentum 96
Optical microscope 17
Oral lesions 142
Orange cells 141
Osmium tetroxide 43, 46
Osmolarity 41
Osseous tissue 10
Osteoblasts 11
Osteocytes 11
Oven, drying 83
Oxalic acid 177
Oxidases 126
staining for 117
Oxidizing agents 42
Oxitol 59
Pancreas 96
Papanicolaou method 148
Paper boat 70f
Parabasal cells 137
Paraffin blocks, storage of 71
Paraffin embedded tissues 172
Paraffin embedding 62
wax 69
Paraffin sections 106, 110
Paraffin wax 63t, 68
embedding 70
processing 163
removal of 106
Paraplast 68, 69
Parasites 122, 126, 153
Pathology museum, functions of 156
Penetrating lesion 143
Perani's fluid 53
Periodic acid
Schiff reaction 112
solution 112
Perl's Prussian blue method 115
Peroxidase 117, 126, 173
pH value 178t
Phagocytosis 2
Phase contrast microscopy 24, 24f
Phosphate, fixatives containing 57
Phosphoric acid 177
Photosensitive resins 130
Picric acid 43, 126
fixatives containing 58
Pigments 2
particulate 36
staining of 114
Plasma cells 1, 8
Plastic embedding 73
cassettes 70
moulds 70
Plastic ice trays 70
Plastic spatulas 138
Plasticizer 130
Pneumocystis 123
carinii 123, 140
Polarization light microscopy 29
Polychrome methylene blue 123
Polyester wax 69
Polyethylene glycol 59, 147
Polyfin 70
Polymorphonuclear leukocytes 12
Polyvinyl alcohol 68, 131
Post-fixation procedures 57
aluminium 108
dichromate 43, 177
hydroxide 177
Proctoscopy 170
Prometaphase 3
Propanol 146
Prophase 3, 5
Propylene glycol staining 112
Prostate 96
Prostatic secretion 135
Protein 46
catabolism 6
content 144
denaturing agents 42
Protozoa 122
Quick Papanicolaou staining technique 149
Quinonoid dyes 102
Radiations hazard 161
rate of 101
temperature 55
Reagent 176
accidents 163
loss, rate of 101
Refract 18
Refraction, index of 19
Refrigerated contact 95
Rehydration 172
Resin 83, 84
embedding 73
Resin-embedded tissue 130
Restaining 133
Reticular connective tissue 8, 9f
Reticulin 113, 125
Ribonucleic acids 6
Ribosomes 6
Ringing media 133
Romanowsky stains 150
Rose Bengal 37
Rossman's fluid 46
composition of 46
Rotary microtome 77
Routine fixatives 146
Ruge's fluid 121, 122
Safranine 126
Sample collection, technique of 139
Sarcoidosis 119, 185
Sarcophagidae 33
Sarcoplasm 12
Scanning electron microscope 26, 27f
Schauddin's fixative 122, 147
Schwann cells 14
Secretory cells 137
Section adhesives 83
Section cutting, technique of 84
Seminal fluid 142
Sensory neuron 14
Septicemia 185
Serous effusions 141
Serrations 185
Sex chromatin, stains for 151
Sexual reproduction 185
Shorr staining technique 149
Silicon carbide 81
Silver nitrate 36, 177
staining 113
Skin 96
biopsy 34, 48
with fat 96
Slide 83, 143
labeling of 133f
Smear 147f, 151
of cell samples, mounting of 154
preparation of 37, 144, 145
Smooth muscle 12, 13f
acetate buffer 178
bicarbonate 177
carbonate 177
preparation of 176
carboxy methyl cellulose 68
chloride 177
citrate 141
buffer 178
hydroxide 177, 178
salicylate 83
silicate 84
tetraborate 178
Solid organs, fixation of 157
Spatula 139
Specimen 144
analyze 38
collection 33
containers 35
fixation of 156
fresh 37
labeling of 35
logging of 34
mounting of 158f
organization of 158
preparation of 156, 157
preservation of 157
reception of 156
restoration of 157
thick 145
with low pH 144
Spillage of reagents 161
Spirochetes 126
Spleen 96
Spray fixatives 147, 147f
Spreading, method of 145f
Sputum 135, 140
Squamocolumnar junction 136f
Squamous cells of ectocervix 136
Squamous epithelium 6, 6f
functions 6
Squash preparations 37
Staff training 160
Stainer, automatic 169f
Staining 100, 110, 151
automatic 149
direct 104
dish 106, 107f
equipments 106
automatic 169
special 110
procedures 106, 163
processes, types of 103
racks 106
Stains 102
basic 102
precipitates 114
special 150
types of 101
Starch 83, 84
Stock methenamine silver nitrate solution 121
Stock solution 153
dilution of 177
Stomach 142
Stratified epithelium 7
Stratified squamous epithelium 7, 7f
Streaking 145
method of 145f
Streptavidin 173
Striated muscle fibers 12, 13f
Stropping 82, 83f
technique of 83
Substances, colored 103
Substrate 173
Suitable impregnation medium 62
Sulfuric acid 177
Sulfurous acid solution 112
Sweet's stain 113
Synapse 14
dyes 101
resins 68
Syringe 143
holder 143
Teased preparation 37
Teeth 52
Telophase 3, 5
Temporary mountant 131
Thermoelectric cooling 95
Thionine 123
Thoracoscopy 170
Thrombocytes 12
Thyroid 96
Tissue 1, 6, 32
agitate 67
areolar 8
arrays, advantages of 174
blocks, size of 63
calcified 52
chips 174
nature of 103t
stain 100
containers 66
connective 9
regular connective 9, 9f
density 62
embedding center 70, 70f
examination of 37
fixation of 40, 48, 96
fixation, primary 165
fixed 37
fresh 162
identification 35
in block 71, 71f
labeling of 57
loose connective 8
manually, clearing 67f
marking 36
substances 36
microarray 173
applications of 174
method 174f
prognosis 174
progression 174
synthesis 173
types of 174
mounting 96
orientation 36
processing 57
automatic 64, 66
manual 66
schedules for 64t
steps of 57
ultrasonic-stimulated 167, 167t
proteins 129
sample 35
special 48
selection of 51, 57
size of 48
storage of 48
supporting connective 10
transfer processor 64, 64f
with alcohol 59
Toluene 61
Toluidine blue 123
Toxoplasma 123
Transfer processor 64t
Transitional epithelium 7
stretched 8f
unstretched 8f
Transmission electron microscope 26, 26f
Transmitted dark field illumination 23
Trichloroacetic acid 53
Trichrome stain 122
Troubleshooting cryostat freezing procedure 97t
Tuberculosis 119
carbide 80
hematoxylins 108
Typanosoma 123
Ulcerative colitis 119
Ultramicrotome 79, 168, 168f
Ultrasonic decalcification 165, 165f
Urea, fixatives containing 58
Uric acid 48
Urine 38, 135, 140
cervix 136f
curettings 96
Uterus 96
Utricaria pigmentosa 119
Vacuum impregnation 63
oven 64f
Vacuum, creation of 143
Vaginal pool smear, collection of 140
Vaginal secretion 135
van der Waal's forces 100
van Gieson's stain 111
Vapor fixatives 46
Verhoeff's elastic fiber stain 111
Verhoeff's stain 111
Veronal acetate solution 117
Viscosity 41
nitrocellulose, low 72
Vital staining 103
Water 107, 130
bath method 89, 89f
media 68
waxes 68
tolerant media 69
Watery specimen 145
Wax dispenser 62
Weigert's hematoxylin 109
Weigert's iron
hematoxylin 109
composition of 109
Weigert-Van Gieson staining 110
Wooden Ayre's spatulas 138
Working solution 153, 176
Xylene 60, 130
removal of 106
Zamboni's fixative 98
Zenker's solution 44
Ziehl-Neelsen's stain 120
Chapter Notes

Save Clear

Cell and TissuesCHAPTER 1

It is the basic functional unit of all living systems. It can be described as a mass of protoplasm enclosed within a membrane (plasma/cell membrane). The cells are of different types performing specialized functions, but they have the same common characteristics. The cell is made up of water, protein, carbohydrates, lipids, and inorganic salts.
Structure of a Cell
The various structures present within the protoplasm are nucleus, cytoplasm, and cell membrane (Fig. 1.1).
zoom view
Fig. 1.1: Structure of a cell
It is a somewhat rounded structure present at the center of the cell. It contains genetic materials of the cells. It is bounded by two membranes called as nuclear membrane. The outer membrane contains large number of minute pores called as nuclear pores which are open to the cytoplasm. The nucleus contains a colloidal solution of proteins called nucleoplasm. It contains nucleic acid, DNA and RNA. DNA plays important role in the cell division and transmission of hereditary characters. RNA plays important role in the synthesis of various proteins. RNA is mostly concentrated in a small spherical body present within the nucleus and is called as nucleolus. Aggregations of granules are scattered throughout the nucleus and are called as chromatin granules. Chromosomes appear during cell division and are small thread like structure.
It is a watery and homogenous solution of proteins, sugars and various salts. It contains other organelles like endoplasmic reticulum. Golgi apparatus, mitochondria, centrosome, lysosome, and cytoplasmic inclusions.
  • Endoplasmic/Cytoplasmic reticulum: Cytoplasm contains a network of fine branching tubules known as endoplasmic reticulum (ER). There are two types of ER namely smooth and rough ER. Smooth ER are not coated with ribosomes and are also called as agranular ER, they are responsible for the synthesis of lipids and similar substances. Rough ER are coated with granules of ribosomes and are also called as granular ER, they are associated with protein synthesis. Free ribosomes are also present in the cytoplasm.
  • Golgi apparatus: These are a series of flattened sacs with bulbous parallel ends. Secretory products are concentrated in this area.
  • Mitochondria: These are small filamentous or granular bodies may be distributed evenly throughout the cytoplasm or accumulated in selected sites according to cell types. They are bounded by double membranes. The inner most membrane is reflected to run across the inside of the mitochondria at several points to form shelves called cristae. Mitochondria are called as the power house of the cell and are concerned with cell respiration and enzymatic activity. They supply energy in the form of ATP (Fig. 1.2).
  • Lysosome: This is a spherical organelle bounded by a single membrane and contain a large number of hydrolytic enzymes such as acid phosphatases. These enzymes break down complex molecules into small molecules. Rupture of the lysosome membrane causes release of these enzymes which digest the cell (autolysis). Lysosome play important role in the intracellular digestion of foreign matter within the cell (phagocytosis).
    zoom view
    Fig. 1.2: Structure of mitochondrion
  • Centrosomes: The centrosomes or centrioles present in all the cells and are visible during cell division. They are short, cylindrical bodies whose walls are composed of microtubules arranged longitudinally. During mitosis the two centrioles move to the opposite poles of the cell and support the formation of the spindle along which chromosomes arranged themselves after cell division.
  • Cytoplasmic inclusions: These are non-protoplasmic, nonliving substances found within the cytoplasm. They usually consist of stored nutrients, materials produced by the cell, or ingested particles. Following are some of important inclusions:
    Glycogen: It found in the cytoplasm of liver cells and skeletal muscles.
    Lipid: It stored in lipid cells as fat globule.
    Secretion granules: They are products of cellular synthesis and they are found in the cytoplasm of specialized cells having secretory functions.
    Pigments: It may be exogenous or endogenous in nature. Endogenous pigments are melanin, hemosiderin, etc. and exogenous pigments are foreign particles like coal dust, etc.
    Mucin: It appears as minute granules mainly in mucin producing cells.
Both mitosis and meiosis are types of cell divisions. Mitosis occurs in both reproductive cells and body or somatic cells while meiosis occurs in germ cells or reproductive cells. The former is called as mutiplication, division or replica division as the two daughter cells produced resemble the parent cells. Mitosis occurs in order to favor growth and 3differentiation of an organism. Meiosis called as reduction division as it results in reduction of total number of chromosomes in the daughter cells, in order to maintain a constant chromosome number thereby race is maintained.
Mitosis is the visible part of cell division (Fig. 1.3). By the time mitosis begins all the ‘heavy lifting’ in the form of DNA replication and production of elements necessary for division has already been done. At the start of mitosis, the duplicated DNA exists as chromatin joined at its centromere, but has not yet been packaged in its chromosomal form.
  • Interphase: It occurs just before mitosis begin. DNA is replicated along with organelles and other cellular components and the cell prepares for division.
  • Prophase: The centriole divides, and the chromatin starts to condense. The centrioles are pushed to the poles of the cell by microtubules, i.e. ‘spindles’. The star like configuration, the asta that surrounds the centrioles is also made up of microtubules and actin strands.
  • Prometaphase: The chromatin condenses into chromosomes. The nuclear membrane disappears, and the chromosomes attach themselves to the spindles.
  • Metaphase: The chromosomes align along the equator.
  • Anaphase: The chromosomes divide at their centromere, and start to move along the spindles to their respective poles.
  • Telophase: The nuclear membranes reform round the chromosomes, the chromosomes unwind to form chromatin.
  • Cytokinesis: The actual splitting of the daughter cells into two separate cells is called cytokinesis.
Meiosis only occurs in germ cells, and produces ova in females and sperm in males. In the process of meiosis, the genetic material is reshuffled, and the chromosomes are reduced to their haploid number. During fertilization when the ovum and sperm unite, the diploid number is restored. There are two phases of meiosis viz: meiosis I and meiosis II (Fig. 1.4).
Meiosis I: Meiosis I separates homologous chromosomes, producing two haploid cells (23 chromosomes, N in humans), so meiosis I is referred to as a reductional division. A regular diploid human cell contains 46 chromosomes and is considered 2N because it contains 23 pairs of homologous chromosomes. However, after meiosis I, although the cell contains 46 chromatids it is only considered as being N, with 23 chromosomes.
  • Prophase I: During prophase I, DNA is exchanged between homologous chromosomes in a process called homologous recombination. This often results in chromosomal crossover. The new combinations of DNA created during crossover are a significant source of genetic variation, and may result in beneficial new combinations of alleles. The paired and replicated chromosomes are called bivalents or tetrads, which have two chromosomes and four chromatids, with one chromosome coming from each parent. At this stage, non-sister chromatids may crossover at points called chiasmata (plural; singular chiasma).
    zoom view
    Fig. 1.3: Various stages of mitosis
    zoom view
    Fig. 1.4: Various stages of meiosis
  • Metaphase I: Homologous pairs move together along the metaphase plate. As kinetochore microtubules from both centrioles attach to their respective kinetochores, the homologous chromosomes align along an equatorial plane that bisects the spindle, due to continuous counterbalancing forces exerted on the bivalents by the microtubules.
  • Anaphase I: Kinetochore microtubules shorten, severing the recombination nodules and pulling homologous chromosomes apart. Since each chromosome has only one functional unit of a pair of kinetochores, whole chromosomes are pulled toward opposite poles, forming two haploid sets. Each chromosome still contains a pair of sister chromatids. Nonkinetochore microtubules lengthen, pushing the centrioles farther apart. The cell elongates in preparation for division down the center.
  • Telophase I: The last meiotic division effectively ends when the chromosomes arrive at the poles. Each daughter cell now has half the number of chromosomes but each chromosome consists of a pair of chromatids. The microtubules that make up the spindle network disappear, and a new nuclear membrane surrounds each haploid set. The chromosomes uncoil back into chromatin. Cytokinesis, the pinching of the cell membrane in animal cells or the formation of the cell wall in plant cells, occurs, completing the creation of two daughter cells. Sister chromatids remain attached during telophase I.
  • Interphase II: Cells may enter a period of rest known as interkinesis or interphase II. No DNA replication occurs during this stage.
Meiosis II: Meiosis II is the second part of the meiotic process. Much of the process is similar to mitosis. The end result is production of four haploid cells (23 chromosomes, 1N in humans) from the two haploid cells (23 chromosomes, 1N each of the chromosomes consisting of two sister chromatids) produced in meiosis I. The four main steps of meiosis II are: Prophase II, metaphase II, anaphase II, and telophase II.
  • Prophase II: It takes an inversely proportional time compared to telophase I. In this prophase, we see the disappearance of the nucleoli and the nuclear envelope again, as well as the shortening and thickening of the chromatids. Centrioles move to the polar regions and arrange spindle fibers for the second meiotic division.
  • Metaphase II: In metaphase II, the centromeres contain two kinetochores that attach to spindle fibers from the centrosomes (centrioles) at each pole. The new equatorial metaphase plate is rotated by 90 degrees when compared to meiosis I, perpendicular to the previous plate.
  • Anaphase II: In anaphase II the centromeres are cleaved, allowing microtubules attached to the kinetochores to pull the sister chromatids apart. The sister chromatids by convention are now called sister chromosomes as they move toward opposing poles.
  • Telophase II: Telophase II is similar to telophase I, and is marked by uncoiling and lengthening of the chromosomes and the disappearance of the spindle. Nuclear envelopes reform and cleavage or cell wall formation eventually produces a total of four daughter cells, each with a haploid set of chromosomes. Meiosis is now complete and ends up with four new daughter cells.
Meiosis facilitates stable sexual reproduction. Without the halving of ploidy, or chromosome count, fertilization would result in zygotes that have twice the number of chromosomes as the zygotes from the previous generation. Successive generations would have an exponential increase in chromosome count. In organisms that are normally diploid, polyploidy, the state of having three or more sets of chromosomes, results in extreme developmental abnormalities or lethality. Polyploidy is poorly tolerated in most animal species. Plants, however, regularly produce fertile, viable polyploids. Polyploidy has been implicated as an important mechanism in plant speciation.
Most importantly, recombination and independent assortment of homologous chromosomes allow for a greater diversity of genotypes in the population. This produces genetic variation in gametes that promote genetic and phenotypic variation in a population of offspring.
Cell metabolism is the process by which living cells process nutrient molecules and maintain a living state. Cell metabolism involves extremely complex sequences of controlled chemical reactions called metabolic pathways.
Anabolism: Anabolism is a constructive metabolic process whereby energy is consumed to synthesize or combine simpler substances, such as amino acids, into more complex organic compounds, such as enzymes and nucleic acids.6
Catabolism: Catabolism is a type of metabolic process occurring in living cells by which complex molecules are broken down to produce energy. On balance, catabolic reactions are normally exothermic.
Carbohydrate catabolism: Carbohydrate catabolism is the breakdown of carbohydrates into smaller units. The empirical formula for carbohydrates, like that of theirs monomer counterparts, is CX(H2YOY). Carbohydrates literally undergo combustion to retrieve the large amounts of energy in their bonds.
Fat catabolism: Fat catabolism, also known as lipid catabolism, is the process of lipids or phospholipids being broken down by lipases. The opposite of fat catabolism is fat anabolism, involving the storage of energy, and the building of membranes.
Protein catabolism: Protein catabolism is the breakdown of proteins into amino acids and simple derivative compounds, for transport into the cell through the plasma membrane and ultimately for the polymerization into new proteins via the use of ribonucleic acids (RNA) and ribosomes.
Tissue is a group of cells having similar origin and structure, which performs specific functions. A group of different tissues results in the formation of organ of the body like stomach, lungs, esophagus, etc. Various organs may join together to perform a vital function of the body and are called system like respiratory system, digestive system, etc.
Tissues are classified according to the size, shape and functions of the cells. There are four main types of tissues each of which has subdivision. They are:
  • Epithelial tissues
  • Connective tissues
  • Muscular tissues
  • Nervous tissues.
Epithelial Tissues
Epithelial tissues form the covering of the body and lining of cavities and tubes. It is also found in glands. The cells of epithelial tissues are very closely packed and the intercellular (matrix) substance is very less.
The cells are resting on the basement membrane which is made up of an inert connective tissue. These cells are classified on the basis of their structure and functions such as protection, absorption, excretion, sensory, conduction of materials and regeneration. Epithelial tissues are further subdivided into
  1. Simple epithelium
  2. Stratified epithelium.
Simple Epithelium
Simple epithelium consists of a single layer of similar cells. Depending upon the shape and size of the cells they are further divided into four types. It is usually found on absorptive or secretory surfaces where single layer increases these processes. The types are named according to the shape of the cells, which differ according to their functions. The more active the tissue, the taller are the cells.
  • Squamous epithelium
  • Cuboidal epithelium
  • Columnar epithelium
  • Ciliated epithelium.
Squamous Epithelium
It consists of flat and plate like cells. The cells fit closely together like flat stones forming a thin and very smooth membrane. Each cell has a polygonal shape and is filled with cytoplasm with a flattened nucleus (Fig. 1.5). Complete layer of squamous epithelium rest on a basement membrane. Diffusion takes place freely through this thin, smooth and inactive lining. It is present lining the following organs-heart, blood vessels, lymph vessels, alveoli of the lungs, Bowman's capsule, membranous labyrinth of internal ear, etc.
Functions: Diffusion of the substances and protection of organs.
Cuboidal Epithelium
The cuboidal epithelium consists of cube shaped cells fitting closely together lying on a basement membrane (Fig. 1.6). These cells are present in the form of a single layer in the internal lining of uriniferous tubules in the kidney, ducts of the internal ear and some glands. Function: They perform the function of protection, secretion, absorption and excretion.
zoom view
Fig. 1.5: Squamous epithelium
zoom view
Fig. 1.6: Cuboidal epithelium
Columnar Epithelium
As the name indicates, columnar epithelium consists of single layer of elongated, rectangular cells resting on a basement membrane. Cells have prominent nucleus. They are found lining the following organs: Stomach, small intestine, large intestine, rectum, gallbladder, alveoli and secretary glands. They perform the functions of absorption of digested products, and secretion of mucus (Fig. 1.7).
Ciliated Epithelium
As the name indicates it consists of columnar cells having many hairlike processes called cilia at their free edges. The cilia consist of microtubules inside the plasma membrane that extends from the free border of the columnar cells. By the wave like movement of the cilia, these epithelium helps in propelling the contents of the tube, which they line, in one direction only. Example in oviduct, cilia helps to push the egg towards the uterus, while in nasal passage, they prevent the entry of dust, foreign particles and mucus into respiratory tubes and lungs. Ciliated epithelium is found lining the organs like nasal lining, trachea, bronchial tubules, oviducts and uterus (Fig. 1.8).
zoom view
Fig. 1.7: Columnar epithelium
zoom view
Fig. 1.8: Ciliated epithelium
Stratified Epithelium
Stratified epithelium consists of several layers of cells of various shapes. The superficial layers grow up from below. Basement membranes are usually absent. The main function of stratified epithelium is to protect underlying structures from mechanical wear and tear. There are two main types of stratified epithelium namely stratified squamous epithelium and transitional epithelium.
Stratified Squamous Epithelium
It consists of several layers of cells of different shapes. In the deepest layer the cells are columnar and as they grow towards the surface, they become flattened and are then shed (Fig. 1.9).
Non-keratinized stratified epithelium: It is mostly found on the moist surfaces like buccal cavity, pharynx, esophagus, anal canal, lower portion of urethra, and vagina, conjunctiva of the eyes etc. where they protect the organs from drying, wear and tear.
Keratinized stratified epithelium: The dry surfaces are mostly found to be covered with keratinized stratified epithelium like skin, hair, nails, etc. They protect the surface from wear and tear. This epithelium consists of dead cells containing keratin (protein). This forms a tough, relatively waterproof protective layer that prevents drying of the underlying live cells.
Transitional Epithelium
It is a compound epithelium in which basement membrane is absent. It is composed of several layers of pear shaped cells which are comparatively thinner and have more elasticity. Its outermost layer is composed of pear-shaped cells and innermost layer is composed of cuboidal cells. They are found lining the pelvis of the kidney, urinary bladder, ureters and upper part of the urethra. It allows stretching of these organs when they are filled (Fig. 1.10).
zoom view
Fig. 1.9: Stratified squamous epithelium
zoom view
Fig. 1.10: Transitional epithelium unstretched and stretched
Connective Tissues
These are extensively spread throughout the body. They are found connecting the various parts of the body and provide them suitable support. The cells forming the connective tissues are more widely separated from each other than those forming the epithelium. An intracellular substance, i.e. matrix is present in large amounts. Depending upon the structure and functions connective tissues are classified into following categories.
  • Connective tissue proper
  • Supporting connective tissues
  • Fluid connective tissues.
Connective tissue proper: It consists of a large amount of intercellular materials. It is further classified into loose connective tissue and dense connective tissue.
Loose connective tissue: It is a mass of widely scattered cells whose matrix is a loose weave of fibers. Many of the fibers are strong protein fibers called collagen. Loose connective tissue is found beneath the skin and between organs. It is a binding and packing material whose main purpose is to provide support and hold other tissues and organs in place. Three types of loose connective tissue are recognized. These include areolar, adipose, and reticular types.
Areolar connective tissue: It is loose connective tissue that consists of a mesh-work of collagen, elastic tissue, and reticular fibers with many connective tissue cells in between the mesh-work of fibers. The different types of cells embedded within the areolar tissue are fibroblasts, plasma cells, adipocytes, mast cells, and macrophages. The fibers and cells are embedded in a semifluid ground matrix. Areolar tissue binds skin to the muscles beneath. The key functions of areolar tissue are support, strength and elasticity (Fig. 1.11).
Adipose tissue: It is a loose fibrous connective tissue packed with many cells (called “adipocytes”) that are specialized for storage of triglycerides, i.e. “fats”. Each adipocyte cell is filled with a single large droplet of fat. As this occupies most of the volume of the cell, its cytoplasm, nucleus, and other components are pushed towards the edges of the cell which is bounded by the plasma membrane. Adipose tissue acts as an insulating layer, helping to reduce heat loss through the skin. It also has a protective function, providing mechanical protection (“padding”) and support around some of the major organs, e.g. kidneys. Adipose tissue is also a means of energy storage. Food that is excess to requirements is converted into fat and stored within adipose tissue in the body (Fig. 1.12).
Reticular connective tissue: Reticular connective tissue is named for the reticular fibers which are the main structural part of the tissue. These fibers are present in many types of connective tissue and are particularly heavily concentrated in reticular connective tissue. The cells that make the reticular fibers are fibroblasts called reticular cells.
zoom view
Fig. 1.11: Areolar connective tissue
zoom view
Fig. 1.12: Adipose connective tissue
zoom view
Fig. 1.13: Reticular connective tissue
zoom view
Fig. 1.14: Dense regular connective tissue
zoom view
Fig. 1.15: Dense irregular connective tissue
Reticular connective tissue forms a scaffolding for other cells in several organs, such as lymph nodes, liver, spleen and bone marrow (Fig. 1.13).
Dense connective tissue: They are also called dense fibrous tissue and has fibers as its main matrix element. Dense connective tissue is mainly composed of collagen fibers. Crowded between the collagen fibers are rows of fibroblasts, fibre forming cells, that manufacture the fibers. In addition, these body tissues also contain ground substance - the material that fills in the gaps between fibroblasts and holds the fibers themselves. Ground substance contains fluids and cell adhesion proteins, which essentially act as the glue that keeps the connective tissue attached to the extracellular matrix. Dense connective tissue forms strong, rope like structures such as tendons and ligaments. Tendons attach skeletal muscles to bones; ligaments connect bones to bones at joints. Ligaments are more stretchy and contain more elastic fibers than tendons. Dense connective tissue also makes up the lower layers of the skin (dermis), where it is arranged in sheets.
There are three different types of dense connective tissue: Dense regular connective tissue, dense irregular connective tissue, and elastic connective tissue.
Dense regular connective tissue (White fibrous): In this type of tissue, the collagen fibers are densely packed, and arranged in parallel. This type of tissue is found in ligaments and tendons. These are powerfully resistant to axially loaded tension forces, but allow some stretch (Fig. 1.14).
Dense irregular connective: Tissue has an irregular, somewhat disorderly, dense weave of thick collagen fibers, with bundles of fibers oriented in all directions. With its high tensile strength, dense irregular connective tissue effectively binds various tissues together to form organs and passively translates mechanical forces in all directions without tearing. It is found in several locations: The dermis of the skin, the walls of large tubular organs, such as the alimentary canal, in glandular tissue, and in organ capsules (Fig. 1.15).
Elastic connective tissue: They are thicker and do not exists as bundles. They form ligaments which join the bone with another tissue. They also form the pinna or lobe of the ear, the epiglottis and part of the tunica media of blood vessel walls (Fig. 1.16).10
zoom view
Fig. 1.16: Elastic connective tissue
Supporting connective tissues: These tissues are responsible for the formation of the skeleton of the body. They are further classified into cartilage and bone.
It is a supporting tissue. The cells are nearly rounded in shape and the intercellular spaces are filled with a substance called as matrix. The matrix is tough, gelatinous and elastic in nature formed of chondrin and hence is also called as chondrion. A cartilage consists of cells called chondroblasts which are packed in the matrix. The entire tissue is covered by a tough and fibrous membrane called as perichondrium. Cartilages are of following types hyaline cartilage, fibrocartilage, and elastic cartilage.
Hyaline cartilage: It is composed of collagen fibers which are packed in a translucent and elastic matrix. It has semi transparent and glossy matrix. It is found in the hyoid apparatus (at the base of tip tongue), larynx, trachea, sternum and the end of limb bones. It is also present at the tip of nose (Fig. 1.17).
Fibro cartilage: It has a compact matrix with large amounts of white fibers. It is present in the movable parts of the body which require extra strength like knee joints, joints between scapular and humerus bone of upper arm, intervertebral discs and pubic region (Fig. 1.18).
Elastic cartilage: It contains a network of branching and rejoining collagenous fibers which are yellowish in color. It is present at the tip of the nose, eustachian tube, and pinna. It is highly elastic in nature (Fig. 1.19).
Bone: It is hardest of all the cartilages because its matrix contains fine granular calcium carbonate. It is present in scapula, and spongy ends of the bones (Fig. 1.20).
zoom view
Fig. 1.17: Hyaline cartilage
zoom view
Fig. 1.18: Fibrocartilage connective tissue
zoom view
Fig. 1.19: Elastic cartilage connective tissue
It is also called as osseous tissue. It is the hardest tissue in the body after tooth enamel. It contains a specialized fibrous tissue, which is hardened by deposits of mineral salts mainly calcium phosphate, calcium carbonate, calcium fluoride, and magnesium phosphate.
The long bones of the body, such as those of legs and arms, (femur and humerus) are hollow in the central part which is filled with soft pulp like fatty tissue called bone marrow.11
zoom view
Fig. 1.20: Cross-section of bone
zoom view
Fig. 1.21: Compact and spongy bone
zoom view
Fig. 1.22: Types of blood cells
All the bone consists of four parts periosteum, endosteum, matrix and bone marrow. Periosteum is the outermost thick and tough part made of fibrous connective tissue and a layer of bone cells called osteoblasts (bone forming cells). The endosteum the is innermost layer that lines the cavity of the bone. Matrix lies in between periosteum and endosteum and forms the major part of the bone. There are two types of bone tissues namely compact bone and spongy bone (Fig. 1.21).
Compact bone: It consists of a large number of units called Haversian systems. The Haversian system consists of a central canal called as Haversian canal which contain artery and a vein for blood supply and a nerve. This canal is surrounded by several concentric rows of lamellae. Between the lamella there are spaces called lacunae containing lymph and bone cells called osteocytes. All the lacunae are connected to each other through narrow spaces called canaliculi which permit the flow of food materials and waste matter. The lymph carrying nourishment flows through the canaliculi. In the spaces between the Haversian system there are interstitial lamellae (Fig. 1.20).
Spongy bone: It is also called as cancellous bone. The Haversian canals are much larger and there are fewer lamellae as compared to compact bone. Red bone marrow is always present with cancellous tissue.
These are those connective tissues which circulate throughout the body and transport various metabolites. Basically, they are of two types: Blood and Lymph.
Blood: It is a constantly circulating fluid providing the body with nutrition, oxygen, and waste removal. Blood is mostly liquid, with numerous cells and proteins suspended in it, making blood “thicker” than pure water. The average person has about 5 liters (more than a gallon) of blood. A liquid called plasma makes up about half of the content of blood. Plasma contains proteins that help blood to clot, transport substances through the blood, and perform other functions. Blood is composed of blood cells: Erythrocytes, i.e. red blood cells, leukocytes, i.e. white blood cells and thrombocytes, i.e. platelets (Fig. 1.22).
Erythrocytes: They are non-nucleated biconcave discs, containing hemoglobin. They are responsible for transportation of oxygen, carbon dioxide and minerals.
Leukocytes: They are part of the body's immune system; they destroy and remove old or aberrant cells and cellular debris, as well as attack infectious agents and foreign 12substances. There are several different types of white blood cells, these are granulocytes and agranulocytes.
Granulocytes (polymorphonuclear leukocytes): Leuko-cytes characterized by the differential staining of the granules in their cytoplasm. There are three types of granulocytes: neutrophils, basophils, and eosinophils which are named according to their staining properties.
  • Neutrophils: The are most abundant white blood cells. They are “C” shaped with segmented nucleus. They play a crucial role in fighting infection.
  • Basophils: They are least numbered white blood cells. They have coarse granules with a single, deeply stained nucleus. They are responsible for the production and secretion of antibodies.
  • Eosinophils: These are characterized by large coarse granules having two or more lobed nucleus. They are found in increasing number in chronic bronchitis, asthma and in certain allergies.
Agranulocytes (mononuclear leukocytes): Leukocytes characterized by the apparent absence of granules in their cytoplasm. The cells include lymphocytes, monocytes, and macrophages.
  • Lymphocytes: These are non-granular cells with a very large nucleus. They show some amoeboid movement, but are not actively phagocytes. They are concerned with the production of antibodies.
  • Monocytes: They are the largest of the white blood cells and have a horse-shoe shaped nucleus. They are most powerfully phagocytic and act, mostly as scavengers.
  • Microphages: A type of white blood cell that ingests foreign materials. Macrophages are key players in the immune response to foreign invaders of the body, such as infectious microorganisms.
Thrombocytes also called platelets, are responsible for blood clotting. They change fibrinogen into fibrin. This fibrin creates a mesh onto which red blood cells collect and clot, which then stops more blood from leaving the body and also helps to prevent bacteria from entering the body.
The fluid “lymph” can be described as a tissue in its own right in the same way as the fluid “blood” can be described as “blood tissue”. Lymph is a clear fluid that is similar to plasma, but contains less protein. It flows through lymphatic vessels throughout the body and includes chemicals and cells whose composition vary according to location within the body. Despite being a fluid, lymph is classified as a connective tissue. The major functions of lymph is draining interstitial fluid, transporting dietary lipids is vitamin K, and protecting the body against invasion/infection as it contains leukocytes (particularly lymphocytes and macrophages) (Fig. 1.23).
zoom view
Fig. 1.23: Lymph
Muscular Tissues
It is a type of connective tissue, which help in the movement of body parts by articulating bones with each other. It is contractile and is therefore able to produce movements. The cells, which form this tissue are different from the normal cells as they are shorten or contract. The cells are like long fibers of variable lengths. Each fiber is made of very fine fibers called myofibrils which are arranged in the form of bundles. The muscle fibers may or may not be covered by a layer of connective tissue called sarcolemma. The cytoplasm of the muscular cells is termed as sarcoplasm. There are three types of muscle fibers:
  • Smooth or involuntary muscle
  • Striated muscle fibers
  • Cardiac muscle.
Smooth Muscle
It is also called as involuntary, plain or visceral muscle. It is not under control of the will. The muscle cells are long and spindle-shaped with a nucleus present in the center of the spindle. The cells of these muscles are uninucleate and each nucleus is surrounded by sarcoplasm. These cells generally occur in the form of sheets made of loosely packed fibers of connective tissue (Fig. 1.24). The myofibrils in the sarcoplasm are also present longitudinally and the sarcolemma is absent. In its place the muscle fibers are covered by the plasma membrane. These muscles are present in the lower part of the esophagus, stomach intestine, lungs, walls of blood vessels, urinary bladder and eyes.
Striated Muscle Fibers
The striated muscles are also sometimes called as skeletal muscles, because they are attached to bones where they extend from one bone to the other and help in their movements by their contractions.13
zoom view
Fig. 1.24: Smooth muscle
It works under the control of will hence are called as voluntary muscle. The cells are about 10 to 40 mm in length and are roughly cylindrical in shape (Fig. 1.25).
The sarcolemma is a fine sheath which surrounds each muscle fiber and several nuclei are situated under it. These muscle fibers are present in the form of bundles of muscle fibers or muscle fibrillation. They appear striated because their fibers have regions of different densities, which occur at very precise regular intervals so as to give the whole muscle a characteristic striped or banded appearance. These muscle fibers are present in those movable parts of the body which are under the will of a person, such as tongue, body wall, muscles of arms and legs and the walls of pharynx and esophagus.
Cardiac Muscle
These are found only in the heart where they are capable of constant rhythmic contractions. They are also unique in having the characteristics of both striped and unstriped muscle fibers. The muscle cells are arranged in the form of cylindrical units which are without sarcolemma. The fibers have few branches. All the fibers united and branched in such a way that a network of muscle fibers is formed. The myofibrils have regions of different densities so that their cytoplasm presents an irregular striated appearance. The transverse band-like appearance is also proved by the cell membranes of the adjacent cell walls (Fig. 1.26).
Nervous Tissues
The nervous tissue carries out the special function of carrying messages of stimuli within the body. The properties of ‘irritability#x2019; and ‘conductivity’ are specially developed in the nervous tissue. The nervous tissue is made of nerve cells called neurons. The neurons are supported by a special type of connective tissue called neuroglia.
zoom view
Fig. 1.25: Striated muscle fibers
zoom view
Fig. 1.26: Cardiac muscle
  • Nerve cells: The nerve cells or neurons considerably vary in size and shape. They form gray matter of the nervous system and are found at the periphery of the brain, in the center of the spinal cord, in groups called ganglia outside the brain and spinal cord and as single cells in walls of organs.
  • Axons and dendrites: These are the processes of nerve cells and form the white matter of the nervous system. They are found deep in the brain and at the periphery of the spinal cord and called as nerves or nerve fibers outside the brain and spinal cord.
  • Axon: It consists of axolemma, a membrane of axon and contains axoplasm and myelin, which is a sheath of fatty material surrounding most of the axons and given them white appearance. The myelin sheath is absent at intervals along the length of the axon and near its branching end. These intervals are called “Nodes of Ranvier” and they contribute to rapid transmission of nerve impulse along myelinated fibers. The axons of the neurons which do not possess myelin sheath together form non-myelinated fibers. The axons of all peripheral nerves are surrounded by a very fine delicate membrane called as neurilemma. It consists of a series of ‘Schwann Cells’ which surround the axon and myelin sheath.
  • Dendrites: These are the processes on nerve cells which carry impulses towards nerve cells. These are shorter as compared to axon and each neurons has many dendrites (Fig. 1.27).
Types of Neurons
  • Sensory or afferent neurons: These neurons transmit impulses from the periphery of the body to the spinal cord and then to the brain where they are interpreted and sensed e.g. sense of taste, sight, touch, etc.
  • Motor or efferent neurons: These neurons convey impulses from the brain and spinal cord to other parts of body stimulating glandular secretion or causing muscle contraction.
  • Inter calculated neurons: These are found between sensory and motor neurons and form links in the pathways of nerves.
In the transmission of nerve impulse, whether sensory or motor more than one neuron is always involved. The point at which the nerve impulse passes from one to another is called synapse. Various chemicals known as transmitters are secreted in the synapse and they are involved in the transmission of information across the synapse.
zoom view
Fig. 1.27: A nerve cell
  1. Define cell. Describe the structure of a cell in detail.
  2. Draw well labeled diagram of a cell.
  3. What is cell division? Describe various types of cell division.
  4. What is meiosis? Describe the various steps involved in the process of meiosis.
  5. What is mitosis? Describe phases of mitosis.
  6. Differentiate between meiosis and mitosis.
  7. What is the importance of meiosis and mitosis?
  8. Define metabolism. What are anabolism and catabolism?
  9. What are tissues? Classify tissues with examples.
  10. Describe various epithelial tissues with their functions.
  11. Discuss various simple epithelial tissues with respect to their structure, location and functions.
  12. Describe different stratified epithelium.
  13. What are connective tissues? Give classification with description of each.
  14. What is cartilage? Write about different cartilages present in our body.
  15. What is bone? Describe TC of a bone with the help of well labeled diagram.
  16. Define muscular tissues. Describe types of muscular tissues.
  17. Describe the structure of nervous tissue or neuron with the help of diagram.
  18. Give an account of different types of neurons.
  19. Write short notes on following:
    1. Cytoplasmic inclusions
    2. Ciliated epithelium
    3. Stratified epithelium
    4. Bone
    5. Cardiac muscle
    6. Nervous tissues
1. Which of the following is not an animal tissue?
  1. Connective tissue
  2. Xylem
  3. Epithelial
  4. Nervous
2. Tissues are made of ________.
  1. Groups of cells that perform a different set of functions
  2. Collections of cells that perform similar or related functions
  3. Subcellular structures that aid in the performance of the cell's role
  4. None
3. Which of these is not a function of epithelial tissue ?
  1. Covering surfaces
  2. Secretion
  3. Support of the body
  4. Lining internal exchange areas
4. Layered epithelial tissue is referred to as which of these?
  1. Squamous
  2. Stratified
  3. Voluntary
  4. Pseudostratified
5. Which of these cell types covers the nasal lining?
  1. Stratified epithelium
  2. Cartilage
  3. Blood
  4. Cuboidal epithelium
6. Protection of the body from infectious organisms is accomplished by which of these tissues?
  1. Bone
  2. Muscle
  3. Nerve
  4. Blood
7. The tissue that link a bone to another bone in a skeletal system is ________tissues.
  1. Epithelial
  2. Connective
  3. Muscular
  4. Nervous
8. Tissues that line the tubules in the kidney are made up of ________.
  1. Adipose
  2. Squamous epithelium
  3. Cuboidal epithelium
  4. Stratified epithelium
9. ________ tissues are the storage of fat.
  1. Adipose
  2. Squamous epithelium
  3. Cuboidal epithelium
  4. Stratified epithelium
10. Glands are composed of tissues.
  1. Epithelium
  2. Connective
  3. Muscle
  4. Nervous
11. Hard part of the body is made of ________tissue.
  1. Blood
  2. Bone
  3. Muscle
  4. Nerves16
12. Bone acts as a reservoir for which of these elements?
  1. Carbon
  2. Hydrogen
  3. Calcium
  4. Nitrogen
13. The major function of bone is. ________
  1. Covering body surface
  2. Support
  3. Movement
  4. Integration of stimulus
14. Formation of blood takes place in. ________
  1. Matrix
  2. Bone marrow
  3. Liver
  4. Adipose tissues
15. The blood cell that transport oxygen within the body are the ________
  1. Macrophages
  2. Erythrocytes
  3. Platelets
  4. Leukocytes
16. ________ is the liquid part of the blood.
  1. Plasma
  2. Adipose
  3. Cartilage
  4. Platelets
17. ________ tissues helps in the contraction of heart.
  1. Cardiac
  2. Skeletal
  3. Smooth
  4. Bone
18. During birth uterus is contracted with the help of the tissue.
  1. Cardiac
  2. Skeletal
  3. Smooth
  4. Transitional epithelium
19. The junction between nerve cells are known as ______.
  1. Gap junction
  2. Synapses
  3. Tight junction
  4. Villi
20. The function unit of the nerves system is ______.
  1. Neuron
  2. Axon
  3. Dendrite
  4. Nephron