Part 1

A TEXT-BOOK of VETERINARY ANATOMY

SEPTIMUS SISSON, S.B., V.S.

PROFESSOR OF COMPARATIVE ANATOMY IN OHIO STATE UNIVERSITY, COLUMBUS, OHIO MEMBER OF THE AMERICAN ASSOCIATION OF ANATOMISTS

WITH 588 ILLUSTRATIONS MANY IN COLORS

PHILADELPHIA AND LONDON W. B. SAUNDERS COMPANY 1911

COPYRIGHT, 1910, BY W. B. SAUNDERS COMPANY

Reprinted July, 1911

PRINTED IN AMERICA

PRESS OF W. B. SAUNDERS COMPANY PHILADELPHIA

KATHERINE OLDHAM SISSON

IN GRATEFUL RECOGNITION OF CONSTANT INSPIRATION AND ENCOURAGEMENT THIS BOOK IS DEDICATED

BY THE AUTHOR

PREFACE

The lack of a modern and well-illustrated book on the structure of the principal domestic animals has been acutely felt for a long time by teachers, students, and practitioners of veterinary medicine. The work here offered is the expression of a desire to close this gap in our literature.

The study of frozen sections and of material which has been hardened by intravascular injection of formalin has profoundly modified our views concerning the natural shape of many of the viscera and has rendered possible much greater precision in topographic statements. The experience of the author during the last ten years, in which almost all of the material used for dissection and for frozen sections in the anatomical laboratory of this University has been hardened with formalin, has demonstrated that many of the current descriptions of the organs in animals contain the same sort of errors as those which prevailed in regard to similar structures in man previous to the adoption of modern methods of preparation.

While the method of treatment of the subject is essentially systematic, topography is not by any means neglected either in text or illustrations; it is hoped that this will render the book of value to the student in his clinical courses and to the practitioner. Embryological and histological data have been almost entirely excluded, since it was desired to offer a text-book of convenient size for the student and a work of ready reference for the practitioner. It is believed that the use of black type for the names of important structures and of small print for certain details or matter of secondary importance will prove useful in this respect.

Veterinary anatomical nomenclature is at present quite chaotic in English-speaking countries. In this work an attempt is made to eliminate some terms which do not appear to the author to fulfil any useful purpose, and others which are clearly erroneous or otherwise undesirable. In many cases the terms agreed upon by the Congresses at Baden and Stuttgart are adopted either in the original Latin or in anglicized form; otherwise these terms are added in parenthesis. The author favors the substantial adoption of this terminology, but considered it desirable to offer a sort of transitional stage at present.

The original illustrations are chiefly reproductions of photographs, many of which were taken by Mr. F. H. Haskett. The preparation of the pictures for reproduction was carried out by Messrs. J. V. Alteneder and W. J. Norris. The author takes pleasure in expressing his appreciation of the care and skill exercised by these gentlemen in this often difficult task.

The author is under great obligation to Professors Ellenberger and Baum in Dresden, to Professor Schmaltz in Berlin, and to their publishers for permission to use or to copy figures from their most excellent works. Their generosity in this matter has made it possible to supply this text with a larger number of high-class illustrations than is to be found in any other. A few figures have been taken from other sources, and proper credit has been given in each case.

For checking over certain data and for assistance in the correction of the proofs the author is much indebted to his associate, Dr. F. B. Hadley.

The author desires to express his high appreciation of the determination and constant effort of the publishers to do all in their power to render the book worthy of favorable reception by the profession for whom it is intended.

OHIO STATE UNIVERSITY, COLUMBUS, OHIO. SEPTIMUS SISSON.

CONTENTS

INTRODUCTION OSTEOLOGY PAGE THE SKELETON 19 Structure of Bones 20 Development and Growth of Bone 22 Composition and Physical Properties of Bone 23 Descriptive Terms 23 The Vertebral Column 24 The Ribs and Costal Cartilages 25 Costal Cartilages 26 The Sternum 26 The Thorax 27 The Skull 27 Bones of the Thoracic Limb 27 Bones of the Pelvic Limb 29 SKELETON OF THE HORSE 31 Vertebral Column 31 Ribs 43 Sternum 45 Bones of the Skull 47 Cranium 47 Face 57 The Skull as a Whole 65 The Cranial Cavity 69 The Nasal Cavity 71 The Paranasal Sinuses 72 Bones of the Thoracic Limb 74 Bones of the Pelvic Limb 92 SKELETON OF THE OX 112 Vertebral Column 112 Ribs 114 Sternum 115 Bones of the Skull 115 The Skull as a Whole 123 Bones of the Thoracic Limb 127 Bones of the Pelvic Limb 131 SKELETON OF THE PIG 136 Vertebral Column 136 Ribs 138 Sternum 139 Bones of the Skull 139 The Skull as a Whole 144 Bones of the Thoracic Limb 146 Bones of the Pelvic Limb 148 SKELETON OF THE DOG 150 Vertebral Column 150 Ribs 153 Sternum 153 Bones of the Skull 153 The Skull as a Whole 159 Bones of the Thoracic Limb 162 Bones of the Pelvic Limb 165

ARTHROLOGY SYNARTHROSES 169 DIARTHROSES 170 AMPHIARTHROSES 172 ARTICULATIONS OF THE HORSE 172 Joints and Ligaments of the Vertebræ 172 Atlanto-occipital Articulation 176 Costo-vertebral Articulations 177 Costo-chondral Articulations 178 Chondro-sternal Articulations 178 Sternal Joints and Ligaments 178 Articulations of the Skull 179 Articulations of the Thoracic Limb 180 Articulations of the Pelvic Limb 190 ARTICULATIONS OF THE OX, PIG, AND DOG 203

THE MUSCULAR SYSTEM—MYOLOGY THE MUSCLES AND ACCESSORY STRUCTURES 211 FASCIÆ AND MUSCLES OF THE HORSE 213 Panniculus carnosus 213 Fasciæ and Muscles of the Head 213 Fasciæ and Muscles of the Neck 224 Fasciæ and Muscles of the Back and Loins 235 Fasciæ and Muscles of the Tail 238 Muscles of the Thorax 240 Muscles of the Abdomen 245 Muscles of the Thoracic Limb 250 Fasciæ and Muscles of the Pelvic Limb 273 MUSCLES OF THE OX 295 MUSCLES OF THE PIG 311 MUSCLES OF THE DOG 318

SPLANCHNOLOGY—THE DIGESTIVE SYSTEM DIGESTIVE SYSTEM OF THE HORSE 330 The Mouth 330 The Tongue 335 The Teeth 338 The Salivary Glands 346 The Pharynx 348 The Œsophagus 350 The Abdominal Cavity 352 The Peritoneum 353 The Pelvic Cavity 354 The Stomach 357 The Small Intestine 360 The Large Intestine 363 The Pancreas 371 The Liver 373 The Spleen 377 The Peritoneum 379 DIGESTIVE SYSTEM OF THE OX 382 DIGESTIVE SYSTEM OF THE SHEEP 405 DIGESTIVE SYSTEM OF THE PIG 410 DIGESTIVE SYSTEM OF THE DOG 423

THE RESPIRATORY SYSTEM RESPIRATORY SYSTEM OF THE HORSE 436 The Nasal Cavity 436 The Larynx 440 The Trachea 448 The Bronchi 450 The Thoracic Cavity 450 The Pleuræ 451 The Lungs 453 THE THYROID GLAND OF THE HORSE 457 THE THYMUS OF THE HORSE 458 RESPIRATORY SYSTEM OF THE OX 458 RESPIRATORY SYSTEM OF THE PIG 464 RESPIRATORY SYSTEM OF THE DOG 466