The authors

Anna Dee Fails, DVM, PhD, is an Assistant Professor in the Department of Biomedical Sciences at Colorado State University in Fort Collins, Colorado, USA.

Christianne Magee, DVM, PhD, Dip ACT, is an Assistant Professor in the Department of Biomedical Sciences at Colorado State University in Fort Collins, Colorado, USA.

Dedication xii

About the Companion Website xiii

Chapter 1: Introduction to Anatomy and Physiology 1

Anatomical Nomenclature, Directional Terms, and Planes of Section 3

Microscopic Anatomy: Animal Cells and Tissues 5

Epithelial Tissues 6

Connective Tissues 11

Muscle Tissue 13

Nervous Tissue 15

The General Plan of the Animal Body 15

Chapter 2: Anatomy and Physiology of the Cell 21

Properties of Life 22

Chemical Composition of the Cell 24

Water 24

Proteins 25

Lipids 26

Carbohydrates 28

Inorganic Substances 29

Acids, Bases, and pH 29

Microscopic Study of the Cell 29

Light Microscopy 30

Electron Microscopy 32

The Cell Membrane 33

Structure of the Membrane 33

Intercellular Contact and Adhesion 35

Transport Across Cell Membranes 36

Simple and Facilitated Diffusion 36

Osmosis 38

Active Transport 40

Membrane Potentials and Excitable Cells 41

Resting Membrane Potential 41

Excitable Cells and Action Potentials 42

Membrane Receptors and Intracellular Signaling 43

Cytoplasm and Cytoplasmic Organelles 47

Cytoplasm 47

The Golgi Apparatus 47

The Endoplasmic Reticulum and Ribosomes 47

Mitochondria 47

Lysosomes 48

Other Structures 48

Nucleus 49

Structure of the Nucleus 49

DNA and DNA Replication 50

RNA: Transcription and Translation 51

Biotechnology 53

Cell Division 55

Mitosis 55

Meiosis 56

Regulation of Cell Growth and Replication 57

Chapter 3: Embryology 59

Development of Germ Layers 60

Principles of Differentiation 63

Neurulation 63

Mesodermal Differentiation 64

Teratogenesis 66

Chapter 4: The Skeletal System 69

Functions of Bones 70

Terminology 70

Classification of Bones According to Gross Appearance 73

Axial Skeleton 75

Skull 75

Vertebral Column 79

Sternum and Ribs 82

Appendicular Skeleton 83

Thoracic Limbs 83

Pelvic Limbs 87

Chapter 5: Microscopic Anatomy and Growth and Development of Bone 91

Microscopic Anatomy and Formation of Bone 92

Ossification 94

Endochondral (Intracartilaginous) Ossification 94

Intramembranous Ossification 96

Physiology of Bone 96

Bone Mechanics and Remodeling 96

Calcium of Bone 97

Fractures and Fracture Healing 97

Other Pathologic Conditions 99

Chapter 6 Joints 101

Classification of Joints 102

Fibrous Joints 102

Cartilaginous Joints 103

Synovial Joints 103

Other Synovial Structures 104

Movements of Joints 104

Types of Synovial Joints 106

Joints of the Axial Skeleton 107

Joints of the Appendicular Skeleton 108

Joints of the Thoracic Limb 108

Joints of the Pelvic Limb 111

Pathology of Joints and Related Structures 117

Chapter 7 Anatomy of the Muscular System 121

Anatomical Nomenclature of Muscles 122

Types of Muscle Tissue 122

Skeletal Muscle Organization 122

Muscle Attachments 123

Functional Grouping of Muscles 124

Synovial Structures 126

Muscles of the Thoracic Limb 127

Extrinsic Muscles of the Thoracic Limb 130

Muscles Acting on the Shoulder Joint 131

Muscles Acting on the Elbow 132

Muscles Acting on the Distal Limb 133

Muscles of the Pelvic Limb 135

Muscles Acting on the Hip Joint 135

Muscles Acting on the Stifle 141

Muscles Acting on the Hock 142

Muscles Acting on the Digit 142

Muscles of the Head 143

Muscles of Mastication 143

Muscles of Facial Expression 144

Other Muscles of the Head 144

Muscles of the Trunk and Neck 145

Extensors of the Vertebral Column 145

Flexors of the Vertebral Column 150

Abdominal Muscles 150

Muscles of Respiration 151

Chapter 8: The Equine Foot and Passive Stay Apparatus 153

Structure of the Foot 154

Bones and Cartilages 154

Cornified Tissues 155

Tendons 159

Ligaments 160

Synovial Structures 162

Function 163

Concussion and Storage of Energy 163

Stay Apparatus 163

Thoracic Limb 164

Pelvic Limb 166

Chapter 9: Microscopic Anatomy and Physiology of Muscle 171

Skeletal Muscle 172

Structure 172

Excitation, Contraction, and Relaxation 175

Strength of Contraction 179

Drugs That Affect Skeletal Muscle Function 181

Types of Muscle Contraction 182

Smooth Muscle 182

Structure 183

Stress-Relaxation 183

Contraction and Relaxation 184

Role and Sources of Calcium 184

Action Potentials and Slow Waves 185

Autonomic Innervation 186

Cardiac Muscle 187

Excitation and Contraction 187

Cardiac Hypertrophy 188

Chapter 10: Anatomy of the Nervous System 189

Microscopic Neuroanatomy 192

Embryology 194

Central Nervous System 197

Brain 197

Meninges 200

Spinal Cord 202

Peripheral Nervous System 205

Spinal Nerves 205

Cranial Nerves 206

Autonomic Nervous System 206

Sympathetic Nervous System 208

Parasympathetic Nervous System 211

Enteric Nervous System 212

Chapter 11:Physiology of the Nervous System 213

Functional Regions of the Neuron 214

Physiology of the Nerve Impulse 214

Conduction Velocity and Myelination 216

Synaptic Transmission 217

Neurotransmitters 220

Neural Control of Skeletal Muscle 221

Reflexes Involving Skeletal Muscle Contraction 222

Voluntary Movement 223

Physiology of the Autonomic Nervous System 224

Regulation of Autonomic Nervous System Activity 224

Autonomic Neurotransmitters and Their Receptors 226

Regeneration and Repair in the Nervous System 227

Chapter 12: Sense Organs 229

Sensory Receptors 230

Somatosensation 232

Pain 232

Proprioception 233

Touch 234

Visceral Sensations 234

Chemical Senses 234

Gustation 234

Olfaction 235

Hearing and Balance 236

External Ear 236

Middle Ear 238

Internal Ear 238

Physiology of Hearing 239

Mechanisms of Balance 242

Vision 245

Ocular Adnexa 245

Globe 247

Lens 250

Visual Field and Light Path 251

Visual Pathways of the Brain 251

Chapter 13: Endocrinology 253

Hormones and Their Receptors 254

Chemical Classes of Hormones 254

Eicosanoids 255

Hormone Receptors 256

Cellular Effects of Peptide

Hormones 256

Cellular Effects of Steroid and Thyroid Hormones 259

Negative and Positive Feedback Regulation 259

Hypothalamopituitary Axis 260

Hormones of the Neurohypophysis 262

Hormones of the Adenohypophysis 263

Growth Hormone 263

Adrenocorticotropic Hormone 264

Thyroid¿Stimulating Hormone 265

Other Endocrine Glands 268

Parathyroid Glands 268

Pancreatic Islets 270

Epiphysis (Pineal Gland) 271

Chapter 14: The Integument 273

Integument 274

Skin 274

Epidermis 274

Dermis 275

Hypodermis 276

Adnexa of the Skin 276

Hair 276

Glands 278

Modified Epidermis 279

Hooves 280

Horns 282

Dewclaws 283

Chestnuts and Ergots 283

Coat Color in Horses 283

Wool 285

Chapter 15: Blood and Other Body Fluids 287

Blood 288

Formed Elements of Blood and Hematopoiesis 289

Erythrocytes 290

Platelets 293

Leukocytes 294

Plasma and Serum 295

Blood pH 296

Hemostasis and Coagulation 296

Platelets and the Endothelium 297

Intrinsic and Extrinsic Coagulation Pathways 297

Lymph 300

Serous Fluids 300

Chapter 16: Body Defenses and the Immune System 301

Nonspecific Defenses 302

Specific Immune Response 304

B Lymphocytes 304

Immunoglobulins 305

T Cells and Cell¿Mediated Immunity 306

Lymphocyte Origin, Development, and Residence 308

Active and Passive Immunities 308

Immunological Surveillance 308

Lymphatic System 309

Lymphatic Vessels 309

Lymph Nodes 309

Spleen 312

Thymus 313

Tonsils 314

Chapter 17: Anatomy of the Cardiovascular System 315

Heart 316

Pericardium 316

Cardiac Anatomy 317

Vessels 320

Blood Vessels 320

Lymphatic Vessels 320

Pulmonary Circulation 320

Systemic Circulation 321

Aorta 322

Arterial Distribution to the Head 323

Arterial Distribution to the

Thoracic Limb 323

Arterial Distribution to the Pelvic Limb 324

Veins 325

Cranial Vena Cava 326

Caudal Vena Cava 327

Portal System 327

Fetal Circulation 327

Chapter 18: Physiology of the Heart and

Circulation 331

Basic Design and Function of the Cardiovascular System 332

Cardiac Cycle 333

Systole 336

Diastole 336

Heart Sounds and Murmurs 336

Imaging the Heart 337

Electrical Activity of the Heart 337

Sinoatrial Node and Heart Rate 337

Atrioventricular Node and Other Specialized Conductive Cells in the Heart 339

Electrocardiography and Arrhythmias 339

Cardiac Output and Its Regulation 340

Ventricular Filling and Stroke Volume 340

Cardiac...