Chapter IV: Part III: Large and Small Intestine, Ileo-Colic Junction

AND CAECUM 189

I. GENERAL REVIEW OF MORPHOLOGY AND PHYSIOLOGY OF THE
VERTEBRATE INTESTINE 190

I. Midgut or Small Intestine 192

Intestinal Folds 193

Divisions of Small Intestine 194

Structure of Small Intestine 194

1. Secretory Apparatus 194

2. Absorbing Apparatus 195

Valvulae Conniventes 196

II. Endgut or Large Intestine 198

II. SERIAL REVIEW OF THE ILEO-COLIC JUNCTION AND CONNECTED
STRUCTURES IN VERTEBRATES 200

I. Fishes 200

II. Amphibia 201

III. Reptilia 201

IV. Birds 203

V. Mammalia 204

Monotremata 204

Marsupalia 204

Edentata 206

Sirenia 208

Cetacea 209

Ungulata 209

Rodentia 211

Carnivora 212

Cheiroptera 212

Insectivora 213

Primates 213

III. PHYLOGENY OF THE TYPES OF ILEO-COLIC JUNCTION AND CAECUM
IN THE VERTEBRATE SERIES 217

1. Symmetrical Form of Ileo-colic Junction; Mid- and End-gut
in Direct Linear Continuity 221

2. Asymmetrical Development of a Single Caecal Pouch, lateral
to the Ileo-colic Junction, Mid- and End-gut Preserving
their Linear Continuity 223

3. Rectangular Ileo-colic Junction, with Direct Linear
Continuity of Caecum and Colon 225

IV. STRUCTURE OF CAECAL APPARATUS AND SPECIALIZED MORPHOLOGICAL
CHARACTERS OF COLON IN RODENTS AND UNGULATES 229

1. Caecum Proper 229

2. Structural Modifications of Proximal Segment of Colon
analogous in their Functional Significance to the Caecal
Apparatus 230

V. CAECAL APPARATUS AND COLON IN HYRAX. 234

PART IV. MORPHOLOGY OF THE HUMAN CAECUM AND VERMIFORM APPENDIX 237

I. Development of the Caecum and Appendix 237

II. Changes in the Position of the Caecum and Appendix during
normal Development, depending upon the Rotation of the
Intestine and the subsequent Descent of the Caecum 239

III. Variations of Adult Caecum and Appendix 244

_A._ Shape of Caecum and Origin of Appendix. Types and
Variations of Adult Caecum and Appendix 245

_B._ Position and Peritoneal Relations of Appendix 250

_C._ Ileo-Caecal Folds and Fossae 260