Guide to Ruminant Anatomy – Dissection and Clinical Aspects

Mahmoud Mansour, DVM, PhD, is an alumni Professor and course coordinator for large animal anatomy in the Department of Anatomy, Physiology and Pharmacology in the College of Veterinary Medicine, Auburn University, Alabama, USA. Ray Wilhite, MS, PhD, is Coordinator of the Gross Anatomy Lab in the Department of Anatomy, Physiology and Pharmacology in the College of Veterinary Medicine, Auburn University, Alabama, USA. Joe Rowe, DVM, is Senior Lecturer in the Department of Anatomy, Physiology and Pharmacology in the College of Veterinary Medicine, Auburn University, Alabama, USA. Saly Hafiz, DVM, MS, PhD, is Research Assistant and Gross Anatomy Instructor in the Department of Anatomy, Physiology and Pharmacology in the College of Veterinary Medicine, Auburn University, Alabama, USA.

Contributor xv

Preface xvii

Acknowledgments xix

About the Companion Website xxi

1 The Head, Neck, and Vertebral Column 1

1.1 Skull 2

1.2 Mandible 9

1.3 Paranasal Sinuses 9

1.4 Vertebral Column 14

1.5 Teeth and Age Estimation of Cattle and Small Ruminants (Goats and Sheep) 15

1.5.1 Definitions and Criteria for Estimating the Age of Ruminants 21

1.5.2 Steps for Estimating the Age of Cattle 22

1.6 Joints of the Head 24

1.6.1 Temporomandibular Joint 24

1.6.2 Atlantooccipital Joint 24

1.6.3 Mandibular Symphysis 24

1.6.4 Vertebral Joints 25

1.7 Muscles of the Head 25

1.7.1 Cutaneous Muscles 27

1.7.2 Muscles of Facial Expression 27

1.7.3 Muscles of Mastication 28

1.7.4 Pharyngeal Muscles 28

1.7.4.1 Nomenclature of Pharyngeal Muscles 28

1.7.5 Laryngeal Muscles 28

1.7.6 Hyoid Muscles 29

1.7.7 Lingual Muscles 29

1.7.8 Extraocular Muscles 29

1.8 Blood Vessels, Lymph Nodes, and Nerves of the Head 30

1.8.1 Blood Vessels (Arteries and Veins) 30

1.8.2 Lymph Nodes of the Head and Neck 33

1.8.3 Nerves of the Head 35

1.9 Salivary Glands 39

1.10 The Pharynx 40

1.10.1 Oropharynx 40

1.10.2 Nasopharynx 40

1.10.3 Laryngopharynx 40

1.11 Tongue 40

1.12 The Larynx and Hyoid Apparatus 42

1.12.1 Larynx 42

1.12.2 Hyoid Apparatus 43

1.13 The Eye 43

1.13.1 Superficial Features of the Eye 44

1.13.2 Layers of the Eye 46

1.13.3 Sectioning of the Eyeball 48

1.13.4 Drainage Pathway of the Aqueous Humor 48

1.14 Neck Skeleton 48

1.15 Neck Muscles, Nerves, and Vessels 50

1.15.1 Neck Muscles 50

1.15.2 Nerves of the Neck 54

1.15.3 Blood Vessels of the Neck 55

1.16 Nuchal Ligament 56

1.17 Surface Topography (Head and Neck) 57

1.18 Lab ID List for the Head and Neck 60

2 The Thorax 63

2.1 Introduction 64

2.2 Bones of the Thorax 64

2.3 Thoracic Inlet 65

2.4 Basal Border of the Lung and Area for Lung Auscultation 66

2.5 Diaphragmatic Line of Pleural Reflection 66

2.6 Muscles of the Thoracic Wall 68

2.7 Pleura 71

2.7.1 Parietal Pleura 71

2.7.2 Visceral Pleura 72

2.7.3 Connecting Pleura 72

2.7.4 Content of the Pleural Cavity 72

2.7.5 Lung Lobes 72

2.7.6 Mediastinum 74

2.8 Vessels (Arteries and Veins) 74

2.8.1 Blood Circulation: An Overview 75

2.9 Major Veins of the Thorax 76

2.9.1 Cranial Vena Cava 76

2.9.2 Caudal Vena Cava 76

2.9.3 Azygos Veins (Left and Right) 77

2.10 Major Arteries of the Thorax 77

2.10.1 Brachiocephalic Trunk 77

2.10.2 Costocervical Trunk 78

2.10.3 Vertebral Artery 78

2.10.4 Superficial Cervical Artery 78

2.10.5 Internal Thoracic Artery 78

2.11 Lymphatic Structures 78

2.11.1 Thymus 79

2.11.2 Thoracic Duct 79

2.11.3 Mediastinal and Tracheobronchial Lymph Nodes 79

2.12 Nerves (Motor Somatic, Sympathetic, and Parasympathetic) 80

2.12.1 Phrenic Nerve 81

2.12.2 Autonomic Nerves in the Thorax 81

2.12.3 Vagus Nerve 81

2.12.4 Sympathetic Trunk and Sympathetic Ganglia 82

2.13 Heart (Cor) 82

2.13.1 Pericardium 82

2.13.2 External Features of the Heart 82

2.13.3 Interior of the Heart 85

2.14 Point of Maximum Intensity or Puncta Maxima 88

2.15 Lab ID List for the Thorax 88

3 The Abdomen 91

3.1 Lumbar Vertebrae 92

3.1.1 Bovine Lumbar Vertebrae 92

3.1.2 Goat and Sheep Lumbar Vertebrae 92

3.2 Ligaments of Lumbar Vertebrae 93

3.2.1 Supraspinous Ligament 93

3.2.2 Interspinous Ligaments 94

3.2.3 Intertransverse Ligaments 94

3.2.4 Yellow Ligaments (Interarcuate or Ligament Flava) 94

3.2.5 Dorsal and Ventral Longitudinal Ligaments 94

3.2.6 Intervertebral Disc 94

3.3 Abdominal Wall 94

3.3.1 Paralumbar Fossa 94

3.3.2 Nerves of the Paralumbar Fossa (Flank Anesthesia) 95

3.3.3 Cutaneus Trunci and Omobrachialis Muscles 98

3.3.4 Tunica Flava Abdominis 98

3.3.5 External Abdominal Oblique Muscle 98

3.3.6 Internal Abdominal Oblique Muscle 101

3.3.7 Transversus Abdominis Muscle 102

3.3.8 Rectus Abdominis Muscle 102

3.3.9 Rectus Sheath 102

3.4 Abdominal Cavity 105

3.4.1 Dissection Plan 105

3.4.2 Peritoneum 105

3.4.3 Omentum 107

3.4.4 Ruminant Stomach 111

3.5 Intestines 123

3.5.1 Small Intestine 123

3.5.2 Large Intestine 126

3.6 Other Abdominal Organs 130

3.6.1 Liver 130

3.6.2 Spleen 130

3.6.3 Pancreas 130

3.6.4 Kidney 130

3.7 Vessels 134

3.7.1 Arteries 134

3.7.2 Veins 136

3.7.3 Lymphatics 136

3.8 Palpation of the Live Animal 136

3.9 Lab ID List for the Abdomen 137

4 The Pelvis and Reproductive Organs 139

4.1 Bones of the Pelvis 140

4.1.1 Os Coxae (Pelvic Bone) 140

4.2 Sacrosciatic Ligament (Broad Sacrotuberous Ligament) 141

4.3 Pelvic Peritoneal Pouches 142

4.4 Urinary Bladder, Ureters, and Ligaments of the Bladder 142

4.5 Male Genitalia 144

4.5.1 Penis 144

4.5.2 Male Urethra 150

4.5.3 Prepuce 153

4.5.4 Superficial Inguinal (Scrotal) Lymph Nodes 153

4.5.5 Blood Supply to the Pelvic Viscera and Male Genitalia 153

4.5.6 Testes 155

4.5.7 Male Accessory Sex Glands 158

4.6 Female Reproductive Tract 159

4.6.1 Ovaries 159

4.6.2 Uterine Tubes 161

4.6.3 Uterine Horns 162

4.6.4 Uterine Body 162

4.6.5 Uterine Cervix 164

4.6.6 Vagina 164

4.6.7 Female Pudendum 166

4.6.8 Blood Supply of the Female Genital Tract 167

4.6.9 Udder 169

4.7 Live Cow 172

4.8 Lab ID List for the Pelvis and Reproductive Structures 174

5 The Forelimb 177

5.1 Introduction 178

5.2 Bones of the Thoracic Limb 178

5.2.1 Scapula 178

5.2.2 Humerus 180

5.2.3 Radius and Ulna 181

5.2.4 Carpus (Proximal and Distal Rows) 181

5.2.5 Metacarpal Bones (Large Metacarpal or Cannon Bone) 183

5.2.6 Digits 184

5.3 Muscles and Tendons of the Thoracic Limb 185

5.3.1 Extrinsic Muscles of the Forelimb 186

5.3.2 Intrinsic Muscles of the Thoracic Limb 190

5.4 Retinacula 203

5.5 Carpal Canal 203

5.6 Ligaments of the Digits 203

5.6.1 Proximal Interdigital Ligament 204

5.6.2 Distal Interdigital Ligament 204

5.6.3 Annular Ligaments (Palmar, Proximal, and Distal Digital Annular Ligaments) 204

5.6.4 Digital Annular Ligaments (Proximal and Distal) 204

5.7 Hoof (Wall, Sole, Bulb, and White Line) 205

5.8 Arteries and Nerves of the Thoracic Limb 205

5.8.1 Nomenclature of Blood Vessels and Nerves in the Distal Limb 206

5.9 Veins of the Forelimb 207

5.10 Lymphatics of the Thoracic Limb 209

5.11 Nerves of the Thoracic Limb 209

5.11.1 Suprascapular Nerve 210

5.11.2 Subscapular Nerve 211

5.11.3 Axillary Nerve 211

5.11.4 Musculocutaneous Nerve 211

5.11.5 Radial Nerve 211

5.11.6 Median and Ulnar Nerves 212

5.12 Joints of the Forelimbs 212

5.12.1 Shoulder Joint 216

5.12.2 Elbow Joint 217

5.12.3 Carpal Joints 217

5.12.4 Digital Joints 217

6 The Hind Limb 219

6.1 Bones of the Hind Limb 220

6.1.1 Os Coxae (Hip Bone) 220

6.1.2 Femur (Thighbone) 220

6.1.3 Bones of the Leg (Crus) 223

6.1.4 Tarsal Bones 224

6.1.5 Fused Metatarsals III and IV (Large Metatarsal Bone) 225

6.1.6 Metatarsal Sesamoid Bone 225

6.2 Muscles of the Pelvic Limb 226

6.2.1 Muscles Acting on the Hip Joint 226

6.2.2 Muscles Acting on the Stifle Joint 233

6.2.3 Muscles Acting on the Hock and Digits 234

6.3 Blood Vessels and Nerves of the Hind Limbs 239

6.3.1 Overview of Arterial Blood Supply to the Whole Hind Limb 240

6.3.2 Veins of the Hind Limb 242

6.3.3 Lymphatic Structures of the Hind Limb 242

6.3.4 Nerves of the Hind Limb 244

6.4 Joints of the Hind Limb 250

6.4.1 Hip Joint 250

6.4.2 Stifle Joint 250

6.4.3 Hock (or Tarsus) Joint 251

6.5 Live Cow 251

6.6 Lab ID List for Forelimb and Hind Limb 251

Appendix A Dissection Instructions for a Goat Cadaver 255

A.1 Dissection Labs 255

A.2 Dissection of Goat Neck and Body Cavities (Labs, 1, 2, and 3) 255

A.2.1 Removal of the Thoracic Limb 255

A.2.2 Removal of the Pelvic (Hind) Limb 256

A.2.3 Skinning of the Neck and Flank on the Side Where the Limbs Are Removed 256

A.2.4 Opening the Thorax and Abdomen for Studying the Topography on the Left and Right Sides 257

A.2.5 Thorax 258

A.2.6 Abdomen (In Situ and on Extirpated Viscera) 259

A.2.7 Dissection of Male and Female Pelvis (Lab 4) 260

A.3 Head Dissection (Lab 5) 260

A.4 Forelimb Dissection (Labs 6 and 7) 260

A.5 Hind Limb Dissection (Labs 8 and 9) 261

Videos Captions 261

Appendix B Terminology: Common Terminology and Names 263

Appendix C Further Reading 267

Index 269