THE CECUM 



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diminishes as far as the rectum, where there is a dilatation of considerable size 

 just above the anal canal. It differs from the small intestine in its greater size, 

 its more fixed position, its sacculated wall, and in possessing certain appendages 

 to its external coat, the appendices epiploicae (Fig. 1034), little peritoneal pouches 

 containing fat. 



SACCULATIONS 



APPENDICES EPIPLOICAE 



MUSCULAR BAND 



FIG. 1033. Large intestine. A pfece of transverse colon from a child two years old. The three chief character- 

 istics of the large intestine sacculations, taeniae, and appendices epiploicae are shown. (Cunningham.) 



Further, the longitudinal muscle fibres of the large intestine do not form a con- 

 tinuous layer around the gut, but are arranged in three longitudinal bands or taeniae 

 (taeniae coli) (Fig. 1033). The large intestine, in its course, describes an arch, 

 which surrounds the convolutions of the small intestine. The segment of the 

 intestinal tract where the small intestine joins the large is termed the ileocecal 

 or ileocolic junction. The large intestine commences in the right inguinal region, 

 in a dilated part, the cecum, together with 

 a rudimentary structure, the appendix. 

 It ascends through the right lumbar and 

 right hypochondriac regions to the under 

 surface of the liver; here it takes a bend 

 to the left (hepatic flexure), and passes 

 transversely across the abdomen on the 

 confines of the epigastric and umbilical 

 regions, to the left hypochondriac re- 

 gion; it then bends again (splenic flexure), 

 and descends through the left lumbar re- 

 gion to the left iliac fossa, where it becomes 

 convoluted, and forms the sigmoid flexure ; 

 finally it enters the pelvis, and descends 

 along its posterior wall to the anus. The 

 large intestine is divided into the cecum, 

 colon, rectum, and anal canal. 



MUSCULAR 

 BAND 



MUSCULA 

 BAND 



FIG. 1034. Segment ot large intestine, showing the 

 characteristic features of its structures. (Testut.) 



The Cecum. 



The cecum (intestinum cecum,) (Figs. 1035 and 1036), the commencement of 

 the large intestine, is the large blind pouch situated below the ileocecal valve. 

 Its blind end or fundus is directed downward, and its open end upward, communi- 

 cating directly with the colon, of which this blind pouch appears to be the beginning 

 or head, and hence the old name caput cecum coli was applied to it. Its size is 

 variously estimated by different authors, but on an average it may be said to be 

 two and one-half inches (6.25 cm.) in length and three (7.5 cm.) in breadth. 1 



1 In 435 careful autopsies, Robinson found the cecum and appendix congenitally absent in one case (St. 

 Louis Courier of Medicine, October-December, 1902). Sometimes a very large, sometimes an exceedingly 

 small, cecum is encountered. A large cecum maybe four inches in width, entirely surrounded by peritoneum, 

 and usually is excessively mobile. An adult cecum may be only one inch in width and one-half an inch in 

 length, and it is usually devoid of mobility. 



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