Ebook Histology text and atlas: Part 2

Senior Commissioning Editor: P. Sangeetha
Development Editor: Dr. Alpna Rastogi
Production Editor: Divya Ganesan
Compositor: Idesign
Manager Manu acturing: Anil Kumar Gauniyal
Copyright © 2013 by Wolters Kluwer Health (India)
10th Floor, ower C
Building No. 10
Phase – II
DLF Cyber City
Gurgaon
Haryana - 122002
All rights reserved. T is book is protected by copyright. No part o this book may be reproduced in
any orm or by any means, including photocopying, or utilized by any in ormation storage and retrieval
system without written permission rom the copyright owner.
T e publisher is not responsible (as a matter o product liability, negligence, or otherwise) or any injury
resulting rom any material contained herein. T is publication contains in ormation relating to histology
that should not be construed as speci c instructions or individual patients. Manu acturers’ product
in ormation and package inserts should be reviewed or current in ormation, including contraindications,
dosages, and precautions. All products/brands/names/processes cited in this book are the properties o
their respective owners. Re erence herein to any speci c commercial products, processes, or services
by trade name, trademark, manu acturer, or otherwise is purely or academic purposes and does not
constitute or imply endorsement, recommendation, or avoring by the publisher. T e views and opinions
o authors expressed herein do not necessarily state or ref ect those o the publisher and shall not be used
or advertising or product endorsement purposes.
Care has been taken to con rm the accuracy o the in ormation presented and to describe generally

accepted practices. However, the authors, editors, and publishers are not responsible or errors or
omissions or or any consequences rom application o the in ormation in this book and make no
warranty, expressed or implied, with respect to the currency, completeness, or accuracy o the contents
o the publication. Application o this in ormation in a particular situation remains the pro essional
responsibility o the practitioner. Readers are urged to con rm that the in ormation, especially with
regard to drug dose/usage, complies with current legislation and standards o practice. Please consult ull
prescribing in ormation be ore issuing prescription or any product mentioned in the publication.
T e publishers have made every e ort to trace copyright holders or borrowed material. I they have
inadvertently overlooked any, they will be pleased to make the necessary arrangements at the f rst opportunity.
First Edition, 2013
ISBN-13: 978-81-8473-508-6
Published by Wolters Kluwer (India) Pvt. Ltd., New Delhi.
Printed and bound at Sanat Printers, Haryana.
For product enquiry, plea se contact – Marketing Department (marketing@wolterskluwerindia .co.in) or log
on to our website www.wolterskluwerindia .co.in.


Dedica ted
To my late ather, whose hard work and sacrif ce enabled me to succeed in all that I have endeavoured
To my brother, who took over all the responsibilities a ter our ather passed away
To my mother, or her unwavering support and pro ound devotion
and
To my students, or always keeping me on my toes



Preface

T is book is a result o persistent eedback received rom several o my students about the di culties
aced by them in understanding histology. T e most common concerns related to understanding and

replicating the diagrams correctly, dif erentiating between similar looking slides and getting a sound
grasp o the conceptual details. It was to address these concerns that I took up the project o writing
this book.
I have endeavoured to resolve the above-mentioned di culties by presenting histology in a simple,
interesting and lucid manner. I hope this will make it easier or students to understand and retain concepts
as well as to reproduce the diagrams in their practical manuals.
T e book caters primarily to the requirements o undergraduate medical and dental students.
Pathology students will also nd the book use ul or re reshing histology undamentals.
Some o the key eatures o the book are as ollows:
T e Diagrams
T ere are 118 coloured diagrams o histological slides. T ese simple, clear, well-labelled, hand-drawn
diagrams will help the students in identi cation o the slides. T ey can be easily reproduced by them in
the practical manuals. Important diagrams are also supported by relevant slides. T e 186 line diagrams
and three-dimensional illustrations given in the book will urther aid understanding and retention.
T e ext
Based on the eedback given by an overwhelming majority o students, the text has been presented in a
crisp, bulleted ormat. T e in ormation ows rom basic to detailed with proper structuring in terms o
headings and subheadings to enable easy comprehension.
Identif cation o Similar Looking Slides
T e book has 83 coloured photomicrographs (PMGs) o most o the organs. Studying these pictures will
make the identi cation o actual histological slides easier or the students. Similar looking slides have
been compared and their dif erentiating points have been enumerated separately in the text.
Functional and Clinical Correlations
Several unctional and clinical correlations have been mentioned. T ese not only make the topic
interesting, but also help the students in understanding the importance o histology in the identi cation,
diagnosis and pathogenesis o diseases.


viii

Preface

Key Points
At the end of each chapter, there are key points corresponding to the text and diagrams. T ese key points
will enable a quick revision of the subject by the students.
It has taken me six years of hard work to bring forth this book to you. I hope that it will meet the
expectations of my colleagues and requirements of the students. I shall welcome feedback for further
improvement of the book.
T ank you for choosing to read this book.
Brijesh Kumar



Acknowledgements

I would like to grate ully acknowledge the many individuals without whom it would not have been
possible to bring out the book in its present orm.
I thank my brother, Rajesh Kumar, a constant constructive critic o mine, or teaching me the basics
o computer usage, without which it would have been impossible to write this book electronically.
I express my sincere thanks to all my students, especially Dr. Abhishek Agarwal, Dr. Neha Agarwal,
Dr. Surabhi Ruia and Dr. Sneha Chaudhary, or their eedback and support.
I thank Dr. ara V. Shanbhag (Pro essor, Department o Pharmacology, KMC, Manipal) or her
valuable suggestions. I would also like to thank Dr. K. Ramachandra Bhat (Pro essor, Department o
Anatomy, KMC, Manipal), a pro essor with immense knowledge, who was always encouraging and ready
with help to resolve any doubts that I had.
I thank Mr. Rajiv Banerji (Publishing Director), Ms. P. Sangeetha (Senior Commissioning Editor),
Dr. Alpna Rastogi (Development Editor) and Dr. Munish Khanna (Managing Editor) o Wolters Kluwer
India or their support and valuable suggestions throughout the preparation o this book. I thank all
the staf members o Wolters Kluwer who were involved in this project. It has been a pleasure working
with them.

I would also like to acknowledge my riends and colleagues, Dr. Sneha Guruprasad, Mr. Arvind Kumar
Pandey, Mr. Alok Saxena, Dr. T ejodhar Pulakunta, Dr. Chakravarthy Marx, Ms. Suhani Sumalatha and
Ms. Lydia S. Quadros or their support. T ank you, All!
Last but not least, I want to thank all my amily members or their encouragement, especially my
wi e, Neeraj, and my son, Ishaan, who was born during the period I was working on this book and is
4 years old now. I o ten enjoyed being distracted by him during this journey.
Brijesh Kumar



The Right Approach...

Very o ten, looking into a microscope does not interest the medical student aspiring to become a physician
or surgeon. However, it is important to do this because a oundational knowledge o histology is vital or
budding doctors, and these basics, i understood well, become interesting and even addictive!
What is Histology?
Histology is the study o the microscopic anatomy o cells and tissues o humans, animals and plants.
T e term histology is derived by the combination o two Greek words, histos meaning ‘tissue’ and logia
meaning ‘the knowledge o ’.
Histopathology is the microscopic study o diseased tissue.
Why should it be studied?
Well, here are some o the reasons as to why you should study histology:
·

To understand the functions of an organ
T e microscopic structure o an organ has a distinct correlation to its unctioning and hence its
histological examination helps in gaining a clear understanding o its unctions.

·

For making pathological diagnosis
Histological examination o a diseased tissue is essential or diagnosing certain diseases. T e
diagnosis can be made by observing the digression in the histological appearance o the diseased
tissue rom the normal tissue. Hence, the importance o retaining histological understanding when
studying pathology in the second year.

How should it be studied?
T e ollowing points may be suggested or an ef ective comprehension o histology.
·

Concentrate on the building blocks
- T e our basic tissues—epithelia, connective tissue, muscular tissue and nervous tissue—are
the building blocks o all the organs o the body. Even though the arrangement o these tissues
varies rom organ to organ, it is consistent within an organ. T e understanding o this concept is
undamental to the study o histology. So, study the our basic tissues thoroughly.

·

Analyse the histological slide before putting it under the microscope
- Look at the slide with the naked eye be ore putting in under the microscope. T is will provide
some clue as to what organ it could be.


xii The Right Approach

·

Observe histological slides carefully under the microscope
- Notice the dif erent types o basic tissues present in the histological slide.
- Pay attention to the arrangement o the basic tissues and note how they have been modi ed in

an organ.
ry to nd the reason behind the presence o a particular basic tissue in the organ and
its modi cation. T is will not only help in identi cation o the slide, but it will also help in
understanding the unctions o an organ.

·

Know more to see more
- I you have understood the basics well and i you have read well, you will be able to observe more
eatures in a histological slide than the student who has not read the topic in detail.

·

Don’t cram
- Last but not the least, try to ollow the above-mentioned method or systematically viewing and
understanding a histological slide. I the understanding is sound, retention will happen. Don’t
ocus on simply cramming or reproducing content in the exam.
Brijesh Kumar


Detailed Table of Contents

Dedication
Preface
Acknowledgements
T e Right Approach...

Chapter 1

v

vii
ix
xi

issue Preparation for Histological Study

Steps of issue Preparation 1
Stains 2
Special Histological echniques
Light Microscope 3

2

Chapter 2 Getting Oriented to the Sectional Planes
Interpreting Histological Slides

5

5

Chapter 3 T e Cell
ypes of Cells 9
Plasma Membrane
Cytoplasm 14
Nucleus 21
Cell Cycle 23

1

9

9

Chapter 4 Epithelia and Glands

28

Structural Organisation of the Human Body 28
Epithelial issue 29
Glands 39

Chapter 5 Connective issue
Extracellular Matrix 49
Cells of the Connective issue 53
ypes of Connective issue 57
Basement Membrane 60

48


xiv

Detailed Table of Contents

Chapter 6 Cartilage
Perichondrium 62
Components o Cartilage
Types o Cartilage 64
Hyaline Cartilage 64
Elastic Cartilage 67

Fibrocartilage 68

62
63

Chapter 7 Bone

71

Components o the Bone 71
Coverings o the Bone 74
Classif cation o Bone 74
Long Bone 74
Woven (Immature) Bone 76
Lamellar (Mature) Bone 76
Ossif cation 80
Bone Growth 89
Blood Supply o a Long Bone 91

Chapter 8 Nervous Tissue

95

Neurons 95
Glial Cells 98
Types o Nerve Fibres 100
Membrane Potential and Impulse Conduction
Synapse 103
Classif cation o Nervous Tissue 104
Peripheral Nerves 104

Ganglia 106
Response o Nerve Tissue to Injury 109

Chapter 9 Muscle Tissue

102

112

Skeletal Muscle 112
Cardiac Muscle 119
Smooth Muscle 121
Other Contractile Cells 123

Chapter 10

Circulatory System

Components o the Circulatory System
Blood Vessels 125
Arteries 127
Capillaries 129
Veins 131
Arteriovenous Anastomosis 133
Lymphatic Vascular System 134

125
125

Detailed Table of Contents

Chapter 11 Lymphoid (Immune) System

xv

137

Immunity 137
Lymphoid System 138
T ymus 142
Lymph Node 144
Spleen 148
Palatine onsil 152

Chapter 12

Oral Cavity

156

Oral Mucosa 157
Lips 157
ooth 159
ongue 160

Chapter 13 Gastrointestinal ract
General Microscopic Features of GI
Oesophagus 170
Stomach 172

Small Intestine 180
Large Intestine 188

167

168

Chapter 14 Accessory Glands of the Gastrointestinal ract

196

Salivary Glands 196
Liver 203
Pancreas 210
Gallbladder 213

Chapter 15 Respiratory System
Respiratory ract
Pleura 231

218

Chapter 16 Urinary System
Kidneys 234
Ureter 244
Urinary Bladder
Urethra 247

218

234

246

Chapter 17 Male Reproductive System
estis 251
Epididymis 257
Vas Deferens 258
Prostate 260
Seminal Vesicle 262
Bulbourethral Glands
Penis 263

263

250


xvi

Detailed Table of Contents

Chapter 18 Female Reproductive System

266

Ovaries 267
Fallopian ube 271
Uterus 274
Cervix 277

Vagina 278
Mammary Gland 279

Chapter 19 Placenta and Umbilical Cord
Placenta 287
Umbilical Cord

287

294

Chapter 20 T e Endocrine Glands

296

Pituitary Gland 296
T yroid Gland 303
Parathyroid Glands 307
Adrenal Glands 308

Chapter 21 Central Nervous System

317

Spinal Cord 317
Cerebellum 319
Cerebrum 322
Meninges 324

Chapter 22 Skin

Epidermis 330
Dermis 333
Skin Appendages

328

334

Chapter 23 Sense Organs
Eye 341
Structures Associated with Eyes
Ear 353
Cutaneous Receptors 362
Index

341
349

365


C H AP T E R 1

Tissue Prepar ation for
Histological Study

STEPS OF TISSUE PREPARATION
o prepare tissue or histological slides, the ollowing steps need to be taken:
1. Fixation
T e collected tissue sample is xed to preserve tissue rom degradation (autolysis and bacterial

degradation) and to maintain the structure o the tissue.
T e most commonly used xative is ormalin.
2. Dehydration
Removal o water rom the tissue is necessary since water is not miscible with para n wax. Para n
wax is used in embedding, which is described later.
For removal o water, the tissue is submersed successively in alcohol solutions o increasing concentrations (70– 100%).
3. Clearing
Since alcohol is not miscible with para n wax, it has to be removed rom the tissue; this is done
by xylene.
Xylene is miscible with para n wax.
4. Embedding
T e specimen is submersed into melted wax (the temperature o the wax should be just above its
melting point).
T e wax replaces the clearing agent present inside the specimen.
Now the tissue is allowed to cool, and as it cools the paraf n wa x solidi es.
T e solid wax inside and outside the specimen provides physical support to the tissue, both internally and externally. T is physical support is essential in obtaining very thin sections o the tissue.
5. Section cutting
A small block o para n wax containing the tissue is prepared.
Using the microtome (Fig. 1.1), around 5-µm-thick sections o wax-impregnated tissue are obtained.
T ese wax-impregnated sections are f oated on warm water (45°C); this allows the wax to f atten out.
Now, the sections are mounted on glass slides (coated with adhesive) and stained.
6. Staining
Wax is removed rom the section by xylene.
T e section is rehydrated and stained. Staining is essential as most o the tissues are colourless.
Commonly used stains are discussed later in the chapter.
7. Mounting
A ter the histological section is stained, a drop o mounting medium is added to the slide and a cover
slip is placed on it. When the mounting medium solidi es, the cover slip gets adhered to the slide.
Mounting medium commonly used is Canada balsam.
●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●

●


2

Histology: Text and Atlas

Micron s ca le
Block holde r
Knife

Knife holde r
Fly whe e l
Lock

Figure 1.1 Microtome. (Courtesy: Dr. D.R. Singh, Professor & Head, Department of Anatomy, Nepalgunj Medical
College, Banke, Nepal.)

STAINS
●

●

T e dyes used or staining are classi ed as acidic and basic dyes. Acidic dyes stain basic components
o a cell, whereas basic dyes stain acidic components o a cell. Some o the acidic and basic dyes are

mentioned in able 1.1.
Most commonly used dyes are haematoxylin and eosin (H&E).
Table 1.1 Commonly Used Dyes
Acidic dyes

Basic dyes

Eosin

Haematoxylin

Acid fuchsin

Toluidine blue

Orange G

Methylene blue

HAEMATOXYLIN (H)
●
●
●

It is a basic dye.
T e cell components that stain well with haematoxylin are called basophilic. T ey appear purple.
It stains nuclei due to an af nity to nucleic acids.

EOSIN (E)
●

●
●

It is an acidic dye.
T e cell components that stain well with eosin are called eosinophilic or acidophilic. T ey appear pink.
It stains cytoplasm, mitochondria and collagen.

OTHER STAINS
●

Apart rom the above-mentioned stains, there are stains which are used to stain certain speci c components:
(a) Periodic acid–Schif : It selectively stains carbohydrate-containing substances such as glycogen
and basement membrane deep red.
(b) Sudan Black B: It speci cally stains at.
(c) Ela stic Van Gieson stain: It stains elastic bres black and collagen bres red.

SPECIAL HISTOLOGICAL TECHNIQUES
Although H&E stains are commonly used, special methods such as histochemistry, cytochemistry and
immunochemistry are use ul in diagnosing certain diseases and in biomedical research.


Chapte r 1

Tissue Preparation for Histological Study 3

HISTOCHEMISTRY AND CYTOCHEMISTRY
T ese methods are used or identi ying and localising certain macromolecules in the tissue section.
Enzyme activity and speci c chemical reactions o macromolecules are the basis or their detection.
IMMUNOCYTOCHEMISTRY
In this method, a speci c protein (antigen) is detected by using the antibody against that speci c protein.

T e antibodies used are tagged with a f uorescent molecule which helps in detection o antigen– antibody
complex.

LIGHT MICROSCOPE
T e light microscope is so called because it employs visible light to detect small objects.
PARTS OF LIGHT MICROSCOPE (Fig. 1.2)
●

Eyepiece lens: It is the lens at the top that one looks through, and it brings the image into ocus or the eye.
Eye pie ce le ns e s

Obje ctive le ns e s

Arm

S ta ge

Conde ns e r

Coa rs e a djus tme nt knob
Fine a djus tme nt knob

Light s ource

Ba s e

Figure 1.2 Light microscope and its parts.


4

●

●
●

●

●

Histology: Text and Atlas

Objective lens: It projects an enlarged and illuminated image o the object to the eyepiece. Usually,
there are three or our objective lenses in a microscope. Most o the microscopes have objective lenses
o 4X, 10X, 40X and 100X powers; 10X and 40X lenses are mostly used.
Condenser: T e unction o the condenser lens is to ocus the light onto the specimen.
Support and alignment: T is is provided by the arm, base and stage.
(a) Arm: It is a curved portion that holds all the optical parts.
(b) Ba se: It supports the weight o all the parts o the microscope.
(c) Stage: It is a plat orm on which the glass slide is placed.
Light source: Better microscopes have a built-in light source. Natural light can be used as the light
source in microscopes provided with a mirror (concave).
Focusing knobs: When these knobs are rotated, they move the stage up and down or coarse and
f ne adjustment.


C H AP T E R 2

Getting Or iented
to the Sectional Planes

●

●

●

T e various structures (e.g. blood vessels, glands, nerve bres and muscles) in the tissue sample rom
which the histological slide is to be prepared are organised in three-dimensional planes (Fig. 2.1).
During the sectioning o the tissue, very thin slices o the tissue are made. T ese slices are two
dimensional, which means they have only two planes.
T e various structures present in the tissue, which were organised in three dimensions in the intact
tissue, also get cut into thin slices. As a result, in the slide we see these structures in two planes. Hence,
the structures may appear totally dif erent in the section rom how they are in the intact tissue.

Blood ve s s e l
Duct of
s we a t gla nd
S mooth mus cle
bundle

Duct
S we a t gla nd

Blood ve s s e l

Figure 2.1 Three-dimensional view of a tissue showing orientation of various structures present in it.

INTERPRETING HISTOLOGICAL SLIDES
●

●

While interpreting a histological slide, the observer needs to imagine the missing part o the structure
which he/she is observing.
As mentioned earlier, structures may appear dif erent in dif erent planes o the sections. Let us try to
understand this with some examples.


6

Histology: Text and Atlas

SLIDE OF A SOLID STRUCTURE
For the purpose o easy understanding, a solid organ in the body can be compared to a lemon. T e lemon
can be cut in dif erent planes and the changes in its appearance in those planes can be appreciated.
Exa m p le : Se ctio ns o f a Le mo n
●

●

A lemon is cut in transverse, longitudinal and oblique planes. Notice the change in the appearance in
dif erent planes (Fig. 2.2).
Similarly, a solid structure in the tissue may appear dif erent in dif erent sectional planes in the histological slide.

Oblique s e ction
Tra ns ve rs e
s e ction

(a )

Longitudina l
s e ction

(b)

(c)

Figure 2.2 Appearance of a lemon as it is cut in (a) transverse, (b) longitudinal and (c) oblique planes.

SLIDE OF A TUBULAR STRUCTURE
For the purpose o easy understanding, a tubular structure in the body such as a blood vessel can be
compared with a jalebi (the sweet).
Exa m p le : Se ctio ns o f a Ja le b i (the Sw e e t)
A jalebi is cut in transverse and longitudinal planes. Notice how the appearance o a jalebi is totally
dif erent in the longitudinal section (Fig. 2.3).
●


Chapte r 2

Tra ns ve rs e
s e ction

Getting Oriented to the Sectional Planes

7

Longitudina l
s e ction

(a )

(b)

Figure 2.3 Appearance of a jalebi as it is cut in (a) transverse and (b) longitudinal planes.
●

Similarly, in a tissue, the duct, blood vessel or any other coiled tubular structure will appear dif erent
in dif erent sectional planes (Figs 2.1 and 2.4).
S e ctiona l pla ne

1

2

3

Figure 2.4 A sectional plane that passes through a duct at three points: at point 1, the duct is cut transversely; at
point 2, obliquely; and at point 3, longitudinally. Note that at point 3, the section passes through the
wall of the duct, and hence in the section lumen is not seen.