330 THE ABDOMEN AND PELVIS 



Inferiorly, the caecum is supported by the lowest part of the 

 abdominal wall, and, when distended, it may form a palpable, 

 and sometimes visible, tumour in this region, while gurgling 

 can often be produced by manipulations. Owing to its proximity 

 to the right abdominal inguinal (internal abdominal) ring, the 

 caecum and vermiform process are occasionally found in a right 

 inguinal hernia in children. 



In structure the caecum resembles the rest of the large intestine. 

 The longitudinal muscular coat forms three distinct bands or 

 taeniae. Of these one is found on the anterior surface of the 

 bowel, a second on the posterior surface, while the third is placed 

 on the medial surface. These three bands converge on the 

 base of the vermiform process, which they provide with a 

 complete longitudinal coat. The circular muscular coat, as in 

 the small intestine, is uninterrupted, and the mucous coat 

 contains a large amount of lymphoid tissue. 



Three peritoneal fossae or recesses occur near the termination 

 of the ileum. (i) The superior ileo-ccecal recess (ileo-colic) lies in 

 the angle between the ileum and the ascending colon. The an- 

 terior caecal artery raises a fold of peritoneum from the posterior 

 abdominal wall, and it forms the anterior boundary of the recess. 

 The mouth of the fossa looks downwards and to the left. 



(2) The inferior ileo-ccecal (ileo-appendicular) recess lies in 

 the angle between the ileum and the caecum. Its anterior wall 

 is formed by the ileo-caecal fold (bloodless fold of Treves), and 

 its posterior wall is usually formed by the mesentery of the 

 vermiform process. The ileo-caecal fold is triangular in shape ; 

 its apex is situated at the ileo-caecal junction and its base is free, 

 forming the anterior boundary of the mouth of the fossa. 



(3) The cacal (retro-c(ecal) fossa is the largest and most con- 

 stant of the fossae in this region. It extends upwards behind the 

 caecum as far as the line of peritoneal reflection from that viscus 

 to the floor of the iliac fossa. It is sometimes limited laterally 

 by a fold which passes downwards and laterally across the lower 

 part of the right para-colic gutter from the caeco-colic junction. 



The Vermiform Process (Appendix) springs from the 

 postero-medial aspect of the caecum about one inch below 

 the ileo-colic junction, and can always be found by tracing 

 the anterior taenia coli downwards. It is usually about 3! inches 

 long and inch wide, but its length is very variable, being 

 relatively greater in the child than it is in the adult. The 

 orifice of the vermiform process communicates with the caecum 



