62,99 €
Mehr erfahren.
- Herausgeber: John Wiley & Sons
- Kategorie: Fachliteratur
- Sprache: Englisch
Updated anatomy guide for veterinary practitioners and students with case studies, detailed dissection images, and review questions
The Second Edition of Anatomy and Physiology for Veterinary Technicians and Nurses is a comprehensive guide to veterinary anatomy and physiology applicable to clinical practice, with case studies, detailed dissection images, review question, and supporting drawings, tables, and diagrams often overlooked in many comparable lab manuals available.
This new edition consists of twenty-six chapters. It has been reorganized to provide a better flow of chapters and includes new chapters on special senses and sensory physiology as well as extended coverage of feline species. The book has also been updated with relevant diseases in each physiology chapter, more detailed and frequent images, more added online images, and additional study materials for students.
In Anatomy and Physiology for Veterinary Technicians and Nurses, readers will find:
- Matching materials for the physiologic functions of the systems dissected, labeled, and observed to combine both didactic and psychomotor learning concepts
- Information on skeletal, joint, cardiovascular, respiratory, and muscle anatomy as well as the anatomy of the nervous, endocrine, digestive, reproductive, and urinary systems
- Discussion on cells and immunity, functions of common integument, osteology, physiology of joints and muscles, neurophysiology, and renal physiology
- Details pertaining to both mammal and non-mammal species such as avians
- New, detailed case studies and critical thinking questions
The updated edition of Anatomy and Physiology for Veterinary Technicians and Nurses is an essential reference for veterinary technicians and nursing students seeking clear guidance on the subject.
Sie lesen das E-Book in den Legimi-Apps auf:
Seitenzahl: 677
Veröffentlichungsjahr: 2025
Ähnliche
Table of Contents
Cover
Table of Contents
Title Page
Copyright Page
Preface
Acknowledgments
About the Companion Website
Section 1: Anatomy
1 Directional and Anatomical Terms
Introduction
Directional Terms
Additional Terminology
Review Questions
2 Anatomy of the Common Integument
Introduction
Skin
Pads
Haircoat
Claws
Hooves and Horns
Review Questions
3 Anatomy of the Senses
Introduction
General Senses
Special Senses
Review Questions
4 Skeletal Anatomy
Introduction
Vocabulary
Bone Categories
The Skeleton
The Appendicular Skeleton
The Axial Skeleton
Equines
Review Questions
5 Joint Anatomy
Introduction
Movement
Joint Types
The Skull
The Ribs and Vertebral Column
The Pelvis and The Hip
The Shoulder and Thoracic Limb
The Pelvic Limb
Review Questions
6 Muscle Anatomy
Introduction
Cellular Anatomy
Skeletal Muscle
Review Questions
7 Anatomy of the Nervous System
Introduction
The Neuron
The Synapse
The Meninges
The Brain
Cranial Nerves
The Spinal Cord
Peripheral Nervous System
Review Questions
8 Anatomy of the Endocrine System
Introduction
The Hypothalamus
The Pituitary
Pineal Gland
The Peripheral Endocrine System
Review Questions
9 Anatomy of the Urinary Tract
Introduction
The Kidneys
The Ureters
The Urinary Bladder
The Urethra
Avian
Review Questions
10 Cardiovascular Anatomy
Introduction
The Heart
Peripheral Circulation
The Named Arteries
The Named Veins
Review Questions
11 Respiratory Anatomy
Introduction
Entry into the Respiratory System
The Larynx
The Trachea and Lungs
The Pleura
The Anatomy of Breathing
Species Differentiation
Clinical Considerations
Review Questions
12 Gastrointestinal Anatomy
Introduction
Canines and Felines
Species Variation
Review Questions
13 Reproductive Anatomy
Introduction
The Female
The Male
Review Questions
Section 2: Physiology
14 The Cell and Hematology
Introduction
Mammalian Cell Anatomy
The Production of Energy
Mammalian Cell Boundaries
Hematology
Review Questions
15 Functions of the Common Integument
Introduction
Skin
Glands
Hair
The Pads
Claws, Nails, and Hooves
Antlers, Horns, and Beaks
Review Questions
16 Sensory Physiology
Introduction
Receptors and Signals
The Visual System
Proprioception and Equilibrium
The Auditory System
The Olfactory System
The Gustatory System
The Tactile System
Specialized Receptors
Review Questions
17 Osteology
Introduction
The Growth of Bones
Bone Marrow
Cartilage
Avians
Review Questions
18 Physiology of Joints
Introduction
The Immoveable Joints
The Moveable Joints
Review Questions
19 Muscle Physiology
Introduction
Striated Muscle
Non‐Striated Muscle
Innervation
Review Questions
20 Neurophysiology
Introduction
The Neuron
The Action Potential
Signal Transmission
Central and Peripheral Functions
The Brain
The Autonomic Nervous System
Review Questions
21 Endocrine Physiology
Introduction
Endocrine Glands
Regulation of Hormones
Hormone Types
Hypothalamus and Pituitary Gland
The Thyroid Gland
Parathyroid Gland
The Adrenal Gland
The Pancreas and Insulin
Other Endocrine Activities
Prostaglandins and Pheromones
Review Questions
22 Renal Physiology
Introduction
The Nephron
Acid–Base Balance
Blood Pressure and the Renal System
Uremia
Anemia and the Kidney
Species Differences
Review Questions
23 Cardiovascular Physiology
Introduction
Cardiac Muscle
The Heartbeat
Cardiac Output
Flow Through the Heart and Back
Blood Pressure
Autonomic Nervous System Involvement
The Lymphatic System
Review Questions
24 Respiratory Physiology
Introduction
The Basics
Ventilation and Temperature
Residual Capacity
Thoracic Pressure
The Nervous System and Respiration
The Rhythmicity of Breathing
Gas Exchange
Hemoglobin
Carbon Dioxide
Chemoreceptors
Mechanisms to Increase Oxygenation
Species Differences
Review Questions
25 Digestive Physiology
Introduction
The Entryway
The Stomach
Entering the Small Intestine
The Colon
The Liver
Species Differentiation
Review Questions
26 Reproductive Physiology
Introduction
The Female
Hormonal Control
The Male
Fertilization and Pregnancy
Parturition
Review Questions
Appendix 1: Dissection Notes
Muscle Dissection
Accessing the Internal Organs
Appendix 2: The Cranial Nerves
Appendix 3: Selected Muscle Origins and Insertions
Appendix 4: Common Abbreviations
Glossary
References
Bibliography
Further Reading
Index
End User License Agreement
List of Tables
Chapter 1
Table 1.1 Prefixes.
Table 1.2 Suffixes.
Table 1.3 Root words.
Chapter 5
Table 5.1 Examples of synovial joints, their locations and movement descrip...
Chapter 7
Table 7.1 The Cranial Nerves.
Chapter 12
Table 12.1 Canine and feline dental formula.
Chapter 13
Table 13.1 This table outlines the terms used for each sex within each spec...
Table 13.2 The term for the young of each animal.
Table 13.3 Each animal has a differing normal number of mammary glands and ...
Chapter 20
Table 20.1 The effects of each side of the autonomic nervous system.
Chapter 21
Table 21.1 Column 1 shows what the hypothalamus produces to influence the r...
Table 21.2 See below for a summary of each endocrine gland, what it produce...
List of Illustrations
Chapter 1
Figure 1.1
Our clinical case with the area of concern noted in red on the hi
...
Figure 1.2 Directional terms as they pertain to the feline/canine skeleton. ...
Figure 1.3 A laceration is noted on this patient, described as “an approxima...
Figure 1.4 The different sections of the thoracic and pelvic limbs with the ...
Chapter 2
Figure 2.1 Layers of the skin. The epidermis ends at the stratum basale, and...
Figure 2.2 The melanocyte with the cell body in the deepest layer of the epi...
Figure 2.3 Pads of the feline and canine paw.
Figure 2.4 Chestnuts and ergots found on the distal equine limbs.
Figure 2.5 A single strand of hair showing the three layers: the cuticle, th...
Figure 2.6 Types of feathers. “Clipping” a bird’s wings refers to trimming t...
Figure 2.7 The anatomical terms for parts of the horse hoof.
Chapter 3
Figure 3.1 A single taste bud with gustatory cells to help perceive taste. T...
Figure 3.2 Nares and the external alar fold. Note that because of this anato...
Figure 3.3 A bisected cat skull showing the bony fold called nasal turbinate...
Figure 3.4 The external, middle, and inner ear. Note the placement of the os...
Figure 3.5 The organ of Corti. The gelatinous tectorial membrane will move w...
Figure 3.6 The Macula contains a gelatinous matrix similar to the tectorial ...
Figure 3.7 The crista ampullaris, or crista, has a gelatinous cupula that is...
Figure 3.8 The anatomical features of the eye. The ciliary body is made of t...
Figure 3.9 A representation of rod and cone photoreceptors from the retina. ...
Figure 3.10 The chambers of the eye. Note that the aqueous compartment has t...
Figure 3.11
The microscope results from an ear cytology on our patient, Roo,
...
Chapter 4
Figure 4.1 Types of bones. The sesamoid bones shown here are the patellae, w...
Figure 4.2 Features of long bones. The femur is on the left and the humerus ...
Figure 4.3 Landmarks of the scapula.
Figure 4.4 The humerus. Note that cats have a foramen to the medial side of ...
Figure 4.5 The radius and ulna. In normal anatomy, these two bones sit snugl...
Figure 4.6 The carpal bones, metacarpals, and the thoracic limb paw, or the ...
Figure 4.7 Features of the femur in two views.
Figure 4.8 The tibia and fibula. In the living animal, these two bones are a...
Figure 4.9 The bones of the tarsus and pelvic limb paw, or the pes. Each pha...
Figure 4.10 The bones of the pelvis.
Figure 4.11 View of the pelvis with acetabulum magnified to reveal the labru...
Figure 4.12 The mandible with mandibular symphysis highlighted. The mandibul...
Figure 4.13 The bones of the lateral view of the skull as seen on a feline....
Figure 4.14 The external auditory meatus on the canine skull.
Figure 4.15 The bones of the ventral view of the skull as seen on a feline....
Figure 4.16 A caudal view of the skull showing the foramen magnum where the ...
Figure 4.17 The shape of the skull has an effect on everything from how the ...
Figure 4.18 The ribcage with a subset of the sternum. Note the preservation ...
Figure 4.19 The vertebrae as viewed on the whole animal as well as lateral a...
Figure 4.20 The parts of the vertebrae. Each vertebrae contains a spinous pr...
Figure 4.21 The atlas, or cervical vertebrae 1 (C1), and the axis, or cervic...
Figure 4.22 A comparison of the anatomical features of each type of vertebra...
Figure 4.23 The equine lower limb. The caudal‐most bone, distal to the navic...
Figure 4.24 The bovine limb has two digits, each with the same three phalang...
Figure 4.25 The avian skeleton. Note the fused bones as well as the prominen...
Figure 4.26
The view inside the mouth of the puppy. Notice that the distal m
...
Chapter 5
Figure 5.1 A canine in a point position showing both flexion and extension o...
Figure 5.2 The named suture joints of the skull.
Figure 5.3 The syndesmosis joint between the radius and ulna of the forelimb...
Figure 5.4 The mandibular symphysis, an example of a symphysis joint.
Figure 5.5 An example of the components of a synovial joint, all of which co...
Figure 5.6 Examples of synovial joints. From left to right: the condyloid or...
Figure 5.7 The temporomandibular joint (TMJ), a synovial joint in the skull....
Figure 5.8 The costochondral joint, a fibrous joint in the ribcage.
Figure 5.9 The joints and bones of the manus.
Chapter 6
Figure 6.1 A comparison of the three different types of muscle cells: skelet...
Figure 6.2 The skeletal muscle cell with organelles.
Figure 6.3 A single sarcomere in the relaxed state.
Figure 6.4 The smooth muscle cell relaxed and contracted. Note that the beha...
Figure 6.5 The structure of a muscle and fascicles.
Figure 6.6 The platysma is a superficial muscle encompassing most of the hea...
Figure 6.7 Muscle atrophy in the temporalis muscle of a dog with chronic dis...
Figure 6.8 The superficial muscles of the lateral thorax.
Figure 6.9 The pectoral muscles and xiphihumeralis.
Figure 6.10 The deep thoracic muscles. Latissimus dorsi and trapezius are re...
Figure 6.11 The superficial muscles of the abdomen.
Figure 6.12 The deep abdominal muscles with latissimus dorsi and external ab...
Figure 6.13 Muscles of the antebrachium.
Figure 6.14 Superficial muscles of the lateral pelvic limb.
Figure 6.15 Superficial muscles of the medial pelvic limb.
Figure 6.16 Deep muscles of the lateral pelvic limb.
Figure 6.17 Belle’s tail with the characteristic extension and sharp droop d...
Chapter 7
Figure 7.1 The neuron with myelin sheath.
Figure 7.2 The synapse. A presynaptic axon terminal communicates with a post...
Figure 7.3 The sections of the brain: cerebrum, cerebellum, and brainstem. A...
Figure 7.4 The lobes of the brain.
Figure 7.5 The bisected brain.
Figure 7.6 The blood
–
brain barrier. Note the tight junctions between t...
Figure 7.7 The cranial nerves as they emerge from the ventral side of the br...
Figure 7.8 The vagus nerve (from the Latin root word for “wanderer”) is the ...
Figure 7.9 The brachial plexus and the sciatic or ischiatic nerve.
Chapter 8
Figure 8.1 The thyroid and parathyroid glands viewed with the animal in dors...
Figure 8.2 The adrenal glands just beyond the cranial pole of the kidney.
Figure 8.3 The bisected adrenal gland showing the cortex and medulla. The ar...
Chapter 9
Figure 9.1 The general structure of the urinary system, which starts at the ...
Figure 9.2 The kidney. In dogs and cats, the kidney is surrounded by the ren...
Figure 9.3 The bisected kidney. Note that the size of the animal will limit ...
Figure 9.4 The nephron. This image also appears in Chapter 22.
Figure 9.5 The trigone in the dissected bladder.
Chapter 10
Figure 10.1 The layers of the heart and surrounding tissues.
Figure 10.2 The great vessels of the heart.
Figure 10.3 The great vessels of the heart and the major valves with normal ...
Figure 10.4 The chambers of the heart and internal features.
Figure 10.5 The palpable, or easily felt, lymph nodes: the submandibular, th...
Figure 10.6 The thoracic arteries.
Figure 10.7 The abdominal arteries.
Figure 10.8 The thoracic veins.
Figure 10.9 The abdominal veins. Note duplicity of the left renal vein, whic...
Figure 10.10 The abdominal vessels.
Chapter 11
Figure 11.1 The nares and nasal philtrum.
Figure 11.2 A bisected canine head. Note the complex folding of the nasal co...
Figure 11.3 The lungs with the trachea splitting into the main bronchi and t...
Figure 11.4 The trachea with cartilaginous rings.
Figure 11.5 The lobes of the lungs. Note that the heart has been removed.
Figure 11.6 The avian air sacs.
Chapter 12
Figure 12.1 The hard palate overlies the palatine bone. Its rugae (ridges) a...
Figure 12.2 Position of the teeth: the upper teeth are rooted in the incisiv...
Figure 12.3 The modified Triadan chart is a way of identifying each tooth by...
Figure 12.4 Parts of the tooth. The crown is covered by enamel. The bulk of ...
Figure 12.5 Sections of the stomach. The animal’s head is toward the top of ...
Figure 12.6 The lobes of the liver.
Figure 12.7 The duodenum is the next portion of the gastrointestinal tract a...
Figure 12.8 The ileum enters the cecum, which in dogs and cats is vestigial,...
Figure 12.9 The dental pad is not actually pictured here; the lines point to...
Figure 12.10 Features of the bovine gastrointestinal tract. Note the bovine ...
Figure 12.11 The cloaca is the common exit from the avian body for the diges...
Chapter 13
Figure 13.1 The female reproductive system. The animal's head is toward the ...
Figure 13.2 The infundibulum with fimbriae which will gently guide and accep...
Figure 13.3 The female reproductive system with the ventral vagina canal rem...
Figure 13.4 The canine vulva. A normal, partially haired vulva compared to t...
Figure 13.5 The mammary gland and alveoli.
Figure 13.6 The nipples of a canine. Note that the normal paired nipples are...
Figure 13.7 The testicle.
Chapter 14
Figure 14.1 Red blood cell smears that have been prepared using a Romanowsky...
Figure 14.2 A hemoglobin molecule. Hemoglobin is comprised of four globin ch...
Figure 14.3 A microscopic view of the bone marrow to focus on the large Mega...
Figure 14.4 A comparison of each type of white blood cell organized from mos...
Chapter 15
Figure 15.1 In the living animal, the anal glands appear as a pinhole‐sized ...
Figure 15.2 Horn grows out from the cornual process. In bovines, the interio...
Chapter 16
Figure 16.1 The nictitating membrane or “third eyelid” in a hospitalized cat...
Figure 16.2 The parts of the eye. The anterior and posterior chambers are fi...
Figure 16.3 The macula and the cupula which participate in proprioception an...
Figure 16.4 A cat having a Flehmen response when presented with an unfamilia...
Chapter 17
Figure 17.1 (1) Epiphysis, (2) metaphysis, (3) cortical bone, (4) endosteum,...
Chapter 18
Figure 18.1 Gomphosis with the periodontal ligament identified.
Chapter 19
Figure 19.1 The skeletal muscle cell with organelles identified. Note the sm...
Figure 19.2 The sarcomere at rest and contracted. Note that in the contracti...
Chapter 20
Figure 20.1 The neuron schematic as well as a microscopic view of the neuron...
Figure 20.2 The sections of the spinal cord schematic.
Figure 20.3 The sections of the preserved spinal cord as seen through the mi...
Figure 20.4 The wave of depolarization with the absolute and relative refrac...
Figure 20.5 The vagus and trigeminal nerves exit the brain stem. The optic n...
Chapter 21
Figure 21.1 Examples of positive and negative feedback loops. In the positiv...
Chapter 22
Figure 22.1 The nephron. Note that this schematic also appears in Chapter 9....
Figure 22.2 The urinary system of a male as noted by the presence of the pro...
Chapter 23
Figure 23.1 The direct control of the heartbeat arises from the sinoatrial n...
Figure 23.2 The anatomy of the EKG wave.
Chapter 24
Figure 24.1 The expansion of the thorax allows the diaphragm to expand, and ...
Figure 24.2 The alveolus. The venules and arterioles pass around the alveolu...
Chapter 25
Figure 25.1 The modified Triadan chart is a way of identifying each tooth by...
Figure 25.2 Goblet cells.
Chapter 26
Figure 26.1 The developing oocyte and surrounding follicle in the ovary as s...
Figure 26.2 The seminiferous tubules of the testicle under the microscope. E...
Figure 26.3 Spermatozoa.
Guide
Cover Page
Table of Contents
Title Page
Copyright Page
Preface
Acknowledgments
About the Companion Website
Begin Reading
Appendix 1 Dissection Notes
Appendix 2 The Cranial Nerves
Appendix 3 Selected Muscle Origins and Insertions
Appendix 4 Common Abbreviations
Glossary
References
Index
WILEY END USER LICENSE AGREEMENT
Pages
i
ii
x
xi
xii
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
67
68
69
70
71
72
73
74
75
77
78
79
80
81
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
119
120
121
122
123
124
125
127
129
130
131
132
133
134
135
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
159
160
161
162
163
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
181
182
183
184
185
186
187
188
189
190
191
193
194
195
196
197
198
199
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
221
222
223
224
225
226
227
228
229
231
232
233
234
235
236
237
239
240
241
243
245
246
247
248
249
251
252
253
254
255
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
Anatomy and Physiology for Veterinary Technicians and Nurses
A Clinical Approach
Second Edition
Lori Asprea
Long Island University, Rockville Centre, NY, USA
Copyright © 2026 by John Wiley & Sons, Inc. All rights reserved, including rights for text and data mining and training of artificial intelligence technologies or similar technologies.
Published by John Wiley & Sons, Inc., Hoboken, New Jersey.Published simultaneously in Canada.
No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per‐copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750‐8400, fax (978) 750‐4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748‐6011, fax (201) 748‐6008, or online at http://www.wiley.com/go/permission.
The manufacturer’s authorized representative according to the EU General Product Safety Regulation is Wiley‐VCH GmbH, Boschstr. 12, 69469 Weinheim, Germany, e‐mail: [email protected].
Trademarks: Wiley and the Wiley logo are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries and may not be used without written permission. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book.
Limit of Liability/Disclaimer of Warranty: While the publisher and the authors have used their best efforts in preparing this work, including a review of the content of the work, neither the publisher nor the authors make any representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.
For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762‐2974, outside the United States at (317) 572‐3993 or fax (317) 572‐4002.
Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com.
Library of Congress Cataloging‐in‐Publication Data Applied for:Paperback ISBN: 9781394229208
Cover Design: WileyCover Images: Courtesy of Lori Asprea
Preface
The author and the illustrators have all been students at one point in their lives. Some of us have also been teachers and practitioners of veterinary science. We have long talked about putting together a book that reflects how we think about the subjects of anatomy and physiology. For one thing, we sought to have the anatomy and the physiology portions of the book as two separate sections. In some veterinary technology programs, anatomy and physiology are taught as separate courses or in separate portions. Even when they are combined, it can be more helpful to build on the foundation of a complete understanding of anatomy in order to understand the complexity of physiology.
We all agree that adding clinical scenarios makes the information more interesting and, thus, easier to remember. Anatomy and physiology are not part of our curriculum for the sake of theory. A good understanding of anatomy and physiology is the backbone of more advanced areas of study, such as pathology, nutrition, disease, and more. The aim of the study of these topics is to be able to apply this knowledge to daily practice in a clinic, hospital, or research facility.
In this second edition, we have tried to increase the materials included in each chapter, as well as include additional chapters that might be helpful. We have also presented all new case presentations, questions, and some critical thinking questions to stoke curiosity. We have also added more images, illustrations, figures, and appendices. We fervently hope that this work will be of use. We hope equally as much that you, the reader, will let us know what information you would like added or subtracted as we move forward.
We hope that you find this book worthwhile, not only for current study but also for frequent reference. There are also online components that will be of help for people who learn best with visual images rather than written narrative.
Acknowledgments
It is absolutely impossible to write and illustrate a book like this without the support and guidance of dozens of people. It is possible to go on for pages of excruciating detail thanking everyone who has helped us with this project. However, in deference to the reader, we shall endeavor to be brief.
The guidance of our teachers has sustained us and carried us to this moment. We thank the faculty and staff at all the colleges we have attended. We thank our family and friends for their tremendous forbearance. I particularly thank our students for their enthusiasm, their patience, and their encouragement, not to mention their perfect timing when it comes to asking that one last question …
Our good friends at Wiley are, of course, the ones who made this all happen. To Ritu and Atul, and the entire team of incredible people there, our deepest gratitude.
Lori Asprea would like to honor a few special people: the Veterinary Technology faculty at Long Island University; Dr. Seetha Tamma, a dear friend and advisor; the Schwarzman Animal Medical Center; Robin Gelman for her gorgeous illustrations; Olivia Davir for her beautiful artwork and help; my husband Brian, who seems to have an endless supply of patience and encouragement; and finally, Dr. Robin Sturtz, without whom not a single bit of this would have ever come to fruition. Robin Gelman would like to dedicate this book to her husband, Sam Gelman, her inspiration.
Lastly, we all would like to thank the animals in our lives that contribute so much love. Each animal that we have had the honor to know and care for fuels the passion for our field. They are the reason we have constant companionship, even when we work on projects like this, and they don’t understand why we’ve been staring at the glowing screen for so long.
L.A.C.
About the Companion Website
This book is accompanied by a companion website:
www.wiley.com/go/asprea/anatomy_vettech2e
The website includes:
Study questions
Answer Keys
Labelling quizzes
A dissection video
Chapter wise figures from the book
Teaching PowerPoints
Section 1Anatomy
1Directional and Anatomical Terms
Clinical Case: Georgia, a 5‐Year‐Old Female Spayed Domestic Short Hair
A veterinary technician is assisting a doctor with an appointment. While handling the patient, the technician notices a lump on the patient’s hind leg, as shown in Figure 1.1. While reading this chapter, think about the appropriate terminology that should be noted in the patient record for an accurate description of the mass.
Figure 1.1Our clinical case with the area of concern noted in red on the hind limb.
Introduction
The study of anatomy is, put simply, the study of the structure of organisms. It involves looking at architecture, at the different positions, shapes, and sizes of various living tissues. As one might imagine, the anatomy of different species has some things in common and some things that are quite diverse. The structure of the heart is very similar in dogs and cats; it is quite different in equines and reptiles. The kidneys of the dolphin look very different from those of the dog, although they function in the same way. By understanding the differences in anatomy among animals, we can have a greater appreciation for how their body systems function. This understanding is the basis of recognizing states of health and disease.
There are a number of different ways to organize how one looks at anatomy. Gross anatomy refers to features that can be seen with the naked eye. Developmental anatomy is the study of how anatomy changes as the fetus becomes a puppy or a kitten. Topographic anatomy refers to the relation to the parts of the whole (e.g., how the different parts of the kidneys and the connecting conduits make up the urinary system). Regional anatomy refers to the structures of a given area of the body; if one looks at the head, for example, as one unit, it will involve the study of all the muscles, blood vessels, bones, and other tissues that are present. Imaging anatomy refers to the anatomical features as they are seen on a good radiograph. Applied anatomy refers to the anatomy that is most important surgically or for medical treatment. In planning orthopedic surgery, for instance, it is necessary to know not only the structure of the bones but also the local muscles and blood vessels. Most of us use a systems approach when learning anatomy. For example, we study all the bones in the skeletal system, all the muscles in the muscular system, or all the organs in the urinary system.
One of the most important issues in studying anatomy is the understanding of directional terms. If one is asked to find a particular spot on an animal, describing it as “on the leg” is not precise enough. Describing a location using appropriate directional terms makes this much clearer. While the acquisition of vocabulary can be tedious, it is integral to effectively communicate with our clients, veterinarians, and other members of the patient‐care team as well as keep accurate medical records. In other words, good anatomic vocabulary contributes to excellent patient care.
Directional Terms
Directional terms in veterinary medicine are very different from those used in human medicine. The human head is “up” from the hips, while it is “forward” in the dog. This is another reason why it is important to use the proper terms. It is also important to understand that many of these terms are used while referring to, or in relation to, anatomical landmarks to make the description clear. This is the same as when one is giving directions for travel. We don’t say, “The store is far away on Main Street.” We say, “The store is on Main Street, in between avenue A and avenue B, across from the diner.” This tells us exactly where the store is using landmarks around it; in the same way, we use anatomical directional terms to be specific about which body part we are discussing.
Anatomical terminology has many unique terms, prefixes, and suffixes which are derived from Latin and Ancient Greek. As such, these terms for direction can correlate to the terms for the location on the body. Going toward the head is cranial or moving cranially, referring to the cranium or skull. Going in the opposite direction, toward the tail, is caudal or moving caudally, from the Latin word “caud” meaning tail. Going toward the top of the animal that faces the ceiling is moving in a dorsal direction, referring to moving toward the dorsum or “back/spine.” From the top downward is moving in a ventral direction referring to the ventrum or ground‐facing side of the animal from the Latin term for “belly.” Moving toward the center or midline of the animal or a specific limb is considered medial, while moving from the midline toward the side of the animal is lateral.
On the appendages, such as the limbs and tail, or even pinna (ear flaps), we use some special terms. Closer to the body on the appendage is proximal, while moving away from the body on the appendage is moving in a distal direction (Figure 1.2). For example, the elbow is proximal (nearer to the body) than the carpus (wrist). Alternately, you could say the carpus is distal (further from the body) to the elbow. When using these terms to describe a lesion, mass, or injury, we could say, “There is an approximately 6 cm wound immediately distal to the lateral elbow on the right forelimb” (Figure 1.3). This tells us the size of the wound, that it is just below (or farther away from) the elbow on the lateral (outer facing) side of the animal on the right leg. Being described in such a way leaves no room for error when communicating with anyone on the patient care team or in written records.
There are other specialized terms used for direction on the limbs and head. Previously, we discussed that the term cranial was moving toward the head, but once we reach the head, a different term is used: rostral. Rostral is used in the place of cranial only on the head and means toward the nose, derived from Middle English and Old French to mean the “bony beak.” The term rostral remains paired with caudal as its opposite on the head. As an example, one could say “The nose is rostral to the eyes” or “The ears are caudal to the nose” (Figure 1.3).
Additional Terminology
Features of the limbs also get special names. The front legs are referred to as the thoracic limbs, while the rear legs as the pelvic limbs. The shoulder and elbow in dogs are, in medical terms, the scapulohumeral and humeroradioulnar joints, respectively, although they are commonly referred to as shoulder and elbow in discussions with clients and others on the patient care team. The next joint distal to the elbow is the carpus, which is the equivalent of the human wrist. On the pelvic limb, the joint between the femur and tibia is the femorotibial joint, commonly known as the stifle, which is equivalent to the human knee. The next joint going distally is the tarsus. The common name for the tarsus is the hock, a term generally reserved for large animals, all of which is equivalent to the human ankle.
Figure 1.2 Directional terms as they pertain to the feline/canine skeleton. Also noted are some of the major joints.
Figure 1.3 A laceration is noted on this patient, described as “an approximately 6 cm wound immediately distal to the lateral elbow on the right forelimb.” Note the importance of directional and location terms.
Figure 1.4 The different sections of the thoracic and pelvic limbs with the plantar and palmar surfaces noted.
The part of the thoracic limb from the shoulder to the elbow is referred to as the brachium; the area from the elbow to the carpus is referred to as the antebrachium. The area from the head of the femur (the proximal‐most bone of the pelvic limb) to the stifle is called the femoral area. The area from the stifle to the tarsus is technically called the crus, although this term is not commonly used in a clinical setting; the distal pelvic limb is less precise but often used in general practice (Figure 1.4).
When considering the trunk, we have used terms like caudal, dorsal, and ventral. These terms also apply to the limbs. The front of the leg from the shoulder going distally to the paw is the dorsal section, with the back of that same area as the caudal section. On the thoracic limb, the area from the carpus distally, on the caudal surface, and around to and including the ventral surface of the paw that meets the ground is known as the palmar surface. On the pelvic limb, the analogous area from the tarsus to the bottom of the paw is the plantar surface (Figure 1.4).
There are specific names for other parts of the body. The part of the body that includes the chest and abdomen is referred to as the trunk. As discussed earlier, the proper name for the ventral part of the abdomen is the ventrum, while the proper name for the top of the trunk is the dorsum. The lateral surface of the part of the trunk caudal to the chest is the flank.
The part of the trunk from the neck to the caudal ribs is referred to as the thorax. The abdomen refers both to the outer surface (the skin) of the ventrum and to the space within it, extending from the caudal ribs to the pelvis. The space within the thorax is called the thoracic cavity, and the space within the abdomen is called the abdominal cavity. Note, however, that some of the features of each of these cavities are lined by a membrane. The pleural membrane, within the thorax, surrounds the lungs and lines the walls of the thoracic cavity. The area bordered by this membrane is considered to be within the pleural cavity. Similarly, the membrane surrounding some of the organs and lining the interior walls of the abdomen is called the peritoneal membrane, or peritoneum, and that space is called the peritoneal cavity. These cavities and tissues will be discussed again throughout the anatomy and physiology chapters of this text where relevant.
Along with directional and basic anatomical terminology, which allows us to accurately describe the location we desire, we also need to understand the medical language used to discuss these features. Veterinary medical terminology, like any other medical terminology, is a language in and of itself. It is based on a series of prefixes, suffixes, and root words that allow for endless combinations in an effort to accurately describe physiological processes, anatomical parts, diseases, syndromes, and a myriad of other things in medicine. Please refer to Tables 1.1–1.3 for the most common list of these terms along with examples of their use.
Table 1.1 Prefixes.
Term
Referring to
Example
a/an‐
without, not
Anemia – without blood – refers to a low red blood cell count
ab
away from
Abductor – muscle(s) that moves the limb away from the body
ad
toward
Adductor – muscle(s) that move the limb toward the body
ante‐
before, in front of
Antebrachium – before the brachium (lower portion of the limb)
anti‐
against
Antibacterial – an agent (drug, cleanser etc.) against bacteria
auto‐
self
Autoantibodies – antibodies against one’s own tissues
brady‐
slow
Bradycardia – slow heartbeat
bi‐
two
Bilateral – both/two sides
bucco‐
cheek
Buccal pouch – space in between cheek and gums – used for medicine administration
circum‐
around or surrounding
Circumduct – moving a limb around in a circular way
crypto‐
hidden
Cryptorchidism – one or both testicles are undescended and remain in the abdominal cavity
cyan‐
blue
Cyanosis – mucous membranes or skin appearing blue due to lack of oxygen
cyt‐
cell
Cytology – study of cells
dis‐
apart, away
Dissect – cut apart
dys‐
abnormal, bad
Dysplasia – abnormal growth
ex/exo‐
out of, outside, external
Exoskeleton – an outer covering in invertebrates analogous to mammalian skeleton
endo‐
inside
Endoscopy – to look or examine inside with a specialized tool
epi‐
upon, on
Epiglottis – the covering on the trachea
erythr/o‐
red
Erythrocyte – red blood cell
eu‐
good
Eupneic – breathing well/normally. Euthanasia – good death
extra‐
beyond, outside of
Extraocular – just outside the eye
hemi‐
one half
Hemiplegia – paralysis of one side of the body
hetero‐
different
Heterozygous – two different forms of one gene
home/o‐
same
Homeostasis – a steady, balanced state maintained by living things
hyper‐
excess, too much
Hyperthermia – too high of body temperature; febrile
hypo‐
below, under, too little
Hypothermia – too low of body temperature
infra‐
beneath
Infraorbital – beneath the bony orbit of the eye
inter‐
between
Interdigital – in between the digits of the paw or hoof
intra‐
inside, within
Intraocular – within the eye
iso‐
equal, like
Isosthenuria – urine with the same concentration of protein‐free plasma
leuk/o‐
white
Leukocyte – white blood cell
lith‐
stone
Lithotripsy – a procedure using sound waves to break up stones in the body
macro‐
large, long
Macrophage – a type of large white blood cell
melan/o‐
black
Melanocyte – a pigment‐producing cell
meso‐
middle
Mesoderm – the middle layer in a developing embryo
meta‐
beyond
Metacarpus – the bones beyond the carpus
micro‐
small, minute
Microhepatica – small liver
myo‐
muscle
Myocardium – the muscle layer of the heart
necro‐
death
Necrosis – tissue death
neo‐
new
Neonate – newborn
pan‐
everything, all
Panzootic – involving all animals
para‐
next to, alongside
Parathyroid – an organ alongside the thyroid gland
peri‐
around, enclosing
Pericardium – the tissue around the heart
poly‐
many, multiple
Polydactyl – multiple (excessive) digits
post‐
after
Postrenal – after the kidneys, referring to illness
pre‐
before
Prerenal – before the kidneys, referring to illness
pseudo‐
false
Pseudopregnancy – false pregnancy
re‐
again, backward
Reflux – return of fluid backward from it should be – acid reflux from the stomach into the esophagus
retro‐
backward, behind
Retropharyngeal space – area behind the pharynx
semi‐
partially, half
Semilunar – half‐moon shaped, referring to the cardiac valves
sub‐
below, under
Sublingual – under the tongue. Subcutaneous – under the skin
supra‐
above, over
Suprarenal– above the kidney
sy/syl/sym‐
together, joined
Symphysis – a joint where two bones come together; pubic symphysis or mandibular symphysis
trans‐
across, over
Transection – to cut across something
tachy‐
rapid, swift
Tachycardia – fast heart rate
ultra‐
extremely, beyond
Ultrasound – sounds beyond the limit we can hear; sound technology used for imaging
Table 1.2 Suffixes.
Term
Referring to
Example
‐ac
pertaining to
Cardiac – pertaining to the heart
‐algia
pain
Neuralgia – nerve pain
‐ate
having, possessing
Caudate – having a tail
‐blast/o/ic
bud, germ
Osteoblast – a cell that builds the matrix for bone
‐centesis
puncture
Thoracocentesis – puncturing the thoracic cavity with a needle to remove air or fluid
‐cyte
cell
Leukocyte – white blood cell
‐cytosis
referring to cells, many
Leukocytosis – too many white blood cells
‐ectomy
excision, removal
Orchiectomy – surgical removal of the testicles
‐emesis
vomiting
Hematemesis – vomiting blood
‐emia
blood, in the blood
Hyperphosphatemia – excess phosphorus in the blood
‐genesis
origin, beginning of
Pathogenesis – the origin and development of the problem
‐gram
drawn, written
Electrocardiogram – a graph of the heart’s electrical function on the surface of the skin
‐graph
to write
Electrocardiograph – the machine that creates the graph for the electrocardiogram
‐ia
condition of
Hyperglycemia – the condition of having too much sugar in the blood
‐iasis/osis/sis
condition of
Trichiasis – condition of having hair grow in the wrong direction (eyelash)
‐ism
condition of
Hyperthyroidism – condition of having an overactive thyroid gland
‐itis
inflammation of
Sinusitis – inflammation of the sinuses
‐lith
stone
Cystolith – bladder stone
‐logy
study of
Osteology – the study of bones
‐lysis
break down, destruction
Hemolysis – destruction of red blood cells
‐megaly
enlargement
Splenomegaly – an enlarged spleen
‐meter
measuring device
Sphygmomanometer – a manual blood pressure measuring device
‐oid
resembling, like
Fibroid – having a fibrous‐like appearance
‐oma
tumor, cancer
Lipoma – fatty tumor; carcinoma – a malignant tumor of epithelial cells
‐ostomy
opening
Tracheostomy – an opening in the trachea, usually to help breathing
‐otomy
incision
Laparotomy – an incision made into the abdominal wall/cavity
‐pathy
disease
Enteropathy – disease of the small intestine
‐penia
lack of, deficiency
Lymphopenia – deficiency of lymphocytes
‐pexy
fixation
Gastropexy – surgically fixating the stomach to the body wall
‐phagia/phagy
eating
Dysphagia – difficulty eating; polyphagia – eating too much
‐plasia
growth, formation
Neoplasia – new growth, generally referring to a tumor
‐plasty
surgical reconstruction
Episioplasty/Vulvoplasty – surgery to reconstruct the vulva
‐plegia
paralysis
Hemiplegia – paralysis of one side of the body
‐pnea
breath, respiration
Dyspnea – abnormal breathing
‐rrhea
flow or discharge
Diarrhea – flowing watery feces
‐rrhexis
rupture
Enterorrhexis – rupture of the intestine
‐scopy
to examine with a tool
Gastroscopy – to look or examine inside the stomach with a specialized tool
‐stasis
level, unchanging
Homeostasis – a steady, balanced state, maintained by living things
‐stomy
creating an opening
Colostomy – a surgical hole in the colon for waste removal
‐tomy
incising
Tracheotomy – cutting into the trachea
‐tome
cutting instrument
Osteotome – a bone‐cutting instrument
‐trophy
growth
Hypertrophy – increased size or growth of tissue
‐uria
presence in urine
Hematuria – presence of blood in the urine
Table 1.3 Root words.
Term
Referring to
Example
abdomin/o
abdomen
Abdominocentesis – puncturing (with a needle) into the abdominal cavity to remove fluid
aden/o
gland
Adenoma – a benign tumor of a gland
adip/o
fat
Adipose tissue – fatty tissue
arter/o
artery
Arteriole – a small artey
brachi
arm
Brachium – the upper portion of the forelimb. Antebrachium – the lower portion of the forelimb
brachy
short
Brachycephalic – shorter than the average skull length (example: English Bulldog, Pug)
bronch/o
bronchus
Bronchoscopy – using a special tool to see inside the bronchi/ main branches in the lungs
carcin/o
cancer
Carcinoma – cancer of the epithelial tissue, possible in many organ systems
cardi/o
heart
Cardiomegaly – an enlarged heart
carp/o
wrist
Metacarpus – the bones between the wrist and phalanges
cephal/o
head
Mesocephalic – an average‐ or medium‐sized skull length (example: Labrador Retriever)
cerebell/o
cerebellum
Cerebellar hypoplasia – a disease in which the cerebellum fails to grow properly
in utero
cerebr/o
brain, cerebrum
Cerebrospinal fluid – fluid that surrounds the entire brain and spinal cord
col/o
colon/large intestine
Colectomy – surgical removal of a part or all of the colon
cyt/o
cell
Cytotoxin – an agent toxic to living cells
cyst
pouch, bladder
Cystitis – an inflammation of the urinary bladder (“cyst” can refer to the gallbladder as well)
dactyl
digit
Polydactyl – a condition of too many digits per paw
derm/a/o
skin
Dermatology a branch of medicine focusing on the skin and integument
dextr/o
right side
Oculus Dexter (abbrev: OD) – right eye
dolich/o
long, narrow
Dolichocephalic – a longer than average skull length (example: Greyhound, Borzoi)
duct/o
to lead, to carry
Abduction – to lead the limb away from the body
encephala/o
brain
Encephalopathy – any disease or disorder of the brain
enter/o
intestine/small intestine
Gastroenteritis – an inflammation of the stomach and small intestine
esthes/o
nerve sensations
Feline hyperesthesia – a condition in which the patient is extremely sensitive to touch
gastr/o
stomach
Gastrotomy – a surgical incision into the stomach
gingiv/o
gum
Gingivitis – inflammation of the gums
gloss/o
tongue
Glossopharyngeal nerve – a cranial nerve that helps controls tongue movement and more
glyc/gluc/o
(blood) sugar
Hypoglycemia – too low level of sugar in the blood
gnath/o
jaw
Prognathism (mandibular) – a term for an underbite
hemat/o
blood
Hematopoiesis – formation of blood cells
hepat/o
liver
Microhepatica – an abnormally small liver
iatro
medicine, healing
Iatrogenic – illness caused by medical treatment or interventions
ile/o
ileum
Ileocecolic junction – where the ileum, cecum, and colon meet in the digestive tract
jejun/o
jejunum
Jejunostomy tube – a feeding tube placed directly into the jejunum of the small instesine
lingu/o
tongue
Sublingual – under the tongue
mammo/mast
mammary glands
Mastitis – inflammation and infection of the mammary gland(s)
metri/o/a
uterus
Pyometra – pus‐filled uterus
nephro
kidney, nephrons
Nephrology – the study of the kidney and its functions
neuro
nerve, nervous system
Neurology – the branch of medicine that deals with the nervous system
ocul/o
relating to the eye, vision
Intraocular pressure – the amount of pressure inside the eye
onych/o
nail, claw
Onychectomy – a removal of the claws; a declaw
ophthalm/o
relating to the eye
Ophthalmoscope – a tool used to look into the eye to view the retina and other structures
orchi/o
testicle
Orchiectomy – removal of the testicle(s); a neuter
oro
mouth
Oropharynx – an area comprised of the mouth and throat
osseo, oste/o
bony
Osteosarcoma – a cancer of the bones
oto
ear
Otitis externa – an inflammation and infection of the outer ear
path
abnormal, disease
Pathology – a branch of medicine focused on the study and diagnosis of diseases
pharyng/o
pharynx
Nasopharyngoscopy – a procedure to look into the back of the nasal passages and throat
phleb/o
vein
Phlebotomy – removal of blood from veins, usually for laboratory testing
pneum/o
air, breathing, lungs
Pneumothorax – air in the thoracic cavity outside of the lungs
pod/o
foot
Pododermatitis – an inflammation and infection of the skin around the toes and foot
poiesis
creation, formation
Erythropoiesis – formation of red blood cells in the body
poikilo
irregular, varied
Poikilocytosis – an increase in abnormally shaped red blood cells
pulmo/n
lungs
Pulmonary thromboembolism – a blood clot that gets stuck in the blood vessels of the lungs
pyelo
renal pelvis
Pyelonephritis – an infection and inflammation of the renal pelvis and kidney
pyo
pus
Pyoderma – a skin infection that forms pus‐filled blisters or pustules
ren/o
kidney
Adrenal gland – a gland next to the kidney
rhin/o
nose
Rhinoscopy – using a special tool to see into the nasal passages
sinister/o
left side
Auris Sinister (abbrev: AS) – left ear
stoma
mouth, opening
Urethrostomy – an opening made in the urethra to allow urine to pass out of the body
tars/o
ankle or eyelid
Tarsus – the “ankle.” Tarsorrhaphy – partially or completely sewing the eyelids together
therm/o
heat
Hyperthermia – an elevated body temperature
thorac/o
thorax or chest
Thoracotomy – opening the thoracic cavity
trache/o
trachea
Rhinotracheitis – an infectious disease that causes inflammation of the nose and trachea
trich
hair
Trichobezoar – a mass of hair formed in the stomach, a hairball
ure/uro
urine or urea
Uroabdomen – urine freely floating in the abdomen as a result of urinary tract injury
ven
vein
Venule – a small vein
Clinical Case Resolution: Georgia
In the example at the beginning of this chapter, a problem was noted with Georgia’s “hind leg.” This language is not appropriately descriptive for a medical record. Using the terminology learned in this chapter, we should describe this finding as follows: The patient has an approximately 3 cm mass (to describe size) on the left pelvic limb (to describe the side of the patient and limb) proximal to the lateral tarsus (to describe the exact location on the limb).
Review Questions
Define the terms medial, rostral, and dorsal.
Which is more cranial, the thoracic limb or the pelvic limb?
The caudal paw area on the thoracic limb is referred to as the _____ surface.
True or false: The stifle is caudal to the tail.
Define the term “topographic anatomy.”
Go back to the case about Georgia and look at the provided
Figure 1.1
. Describe the mass that was found in relation to the stifle using appropriate directional and anatomical terms.
Refer to
Figure 1.3
where a laceration was described. Describe the injury in relation to the hip using appropriate directional and anatomical terms.
Which of the following terms refers to the liver?
Gastric
Hepatic
Pleural
Renal
Which of the following terms refers to inflammation?
Sarcoma
Hyperthyroid
Bradycardia
Pancreatitis
Which of the following terms refers to muscle?
Leukocyte
Myocardium
Polydactyl
Ultrasound
Extra terminology practice: Use
Tables 1.1
–
1.3
to deduce the meaning of the incorrect answer choices for questions 8, 9, and 10. Example: Gastric – referring to the stomach from the root word “gastr/o.”
2Anatomy of the Common Integument
Clinical Case: Poppy, An Approximately 2‐Year‐Old Female Intact Mixed Breed Dog
This patient is presented to the clinic for an initial examination. The owners report that they found Poppy 2 days ago on the street. Upon examination, it is noted that there are multiple spots of alopecia (missing hair) along the chest and forelimbs, along with erythema (reddened skin) and pruritus (itching). Poppy is also of a thin body condition.
The term integument refers to a broad range of tissues. Knowing the composition and structure of these elements contributes to a broader understanding of the function of this system. This will lead to the ability to recognize what happens in disease states such as the one described above.
Introduction
The integument is a collective term for aspects of bodily structure that are formed of connective tissue and epithelia. Connective tissue is a collection of proteins, fibrous material, and ground elements that form many parts of the mammalian body. An epithelial cell has a specific microscopic structure. Features such as skin, skin glands, fur/whiskers, hooves, horns, and claws are epithelial structures that are parts of the integument. This chapter will focus on the anatomical parts of the integument where the physiological functions will be discussed in Chapter 15. The primary focus is on companion mammals, while certain species‐specific characteristics are discussed throughout.
Skin
Mammalian skin is a complex organ that serves many functions and contains many important parts. The superficial‐most, or outermost layer, is the epidermis. Deep to the epidermis is the dermis. There is a layer of fat and connective tissue deep to the dermis called the subcutaneous layer or the hypodermis. The subcutaneous layer is not skin but is a part of the integument. See Figure 2.1 for a depiction of these layers.
The epidermis has several important specialized cells as well as multiple layers. The specialized cells we can find in the epidermis are keratinocytes, melanocytes, Merkel cells, and Langerhans cells.
Keratinocytes are found throughout the epidermis but begin in the deepest layer. They produce keratin, a tough, fibrous, and waterproof protein that provides skin and other parts of the integument with their strength.
Another specialized cell in the epidermis is melanocytes. Melanocytes have their cell body at the deepest portion of the epidermis with finger‐like projections reaching into the upper layers. See Figure 2.2 for the melanocyte structure. Melanocytes are responsible for producing melanin, which is a type of pigment that gives color to skin and hair, as well as feathers and scales.
Merkel cells are found in the junction where the deepest layer of the epidermis meets the dermis. Merkel cells are specialized sensory cells that perceive light touch. They are connected to nerve endings that can receive touch sensations and send that information to the brain for processing.
Figure 2.1 Layers of the skin. The epidermis ends at the stratum basale, and the dermis ends at the subcutaneous layer.
Figure 2.2 The melanocyte with the cell body in the deepest layer of the epidermis while projections reach up through the layers, depositing melanin. The amount and type of melanin creates a variety of colors.
The last specialized cell that can be found in the epidermis to be discussed is the Langerhans cell. The Langerhans cell can be found in the skin and many other areas of the body. The primary job of this specialized cell is to act as a bodyguard in the skin. It is able to recognize foreign invaders like viruses and bacteria and alert the immune system to take action, thereby protecting the body.
These specialized cells can be found in the layers of the epidermis. Although the epidermis is the outermost portion of skin, it too can be broken down into five individual layers. The deepest layer of cells that make up the epidermis is the stratum basale or basal layer. This layer is where new keratinocytes develop and undergo rapid division. These germinal cells will travel up through the layers of the epidermis undergoing keratinization. The next layer above the stratum basale is the stratum spinosum or the “spiny” layer. Here the keratinocytes that have moved up take on a spiny appearance microscopically, hence their alternate name. The next layer is the stratum granulosum where cells begin to lose their nuclei and glycolipids are introduced to help waterproof the skin. Above the stratum granulosum is the stratum lucidum or “clear” layer. This thin layer is comprised of a few rows of flattened cells and is only visible in thick‐skinned areas like the foot pads. The final and outermost layer of the epidermis is the stratum corneum. This layer is comprised of dead cells that have completely keratinized or cornified. When you are looking at a patient or yourself, the layer of skin you see with the naked eye is the stratum corneum. Refer to Figure 2.1 to view these layers.
