374 



THE LAEGE INTESTINE. 



"Vessels and Nerves. — In the large intestine a similar arrangement of capil- 

 lary plexuses and venous radicles obtains, as lias been described in the stomach 

 (fig. 269). The arrangement of the lymphatics also presents great similarity : 

 the lymphatics of the mucous membrane have here been longer recognized. 



Nei"vous plexuses similar to those of the small intestine are also found in the 

 muscular and submucous coats of the large intestine. 



SPECIAL CHARACTEBS AND CONNECTIONS OF THE DIFFERENT PARTS 

 OP THE LARGE INTESTINE. 



The CiECUM. — The inledmmn ccecimi, or capiit cmcum coli, is that part 

 of the large intestine which is situated below the entrance of the ileum 

 (fig, 270, cc). Its length is about two inches and a half, and its dia- 

 meter nearly the same : it is the widest part of the large intestine. 



The cfecum is situated in the 

 Fig. 270. right iliac fossa, immediately be- 



hind the anterior wall of the ab- 

 domen. It is covered by the 

 peritoneum in front, below, and 

 at the sides : but behind it is 

 usually destitute of peritoneal 

 covering, and is attached by 

 areolar tissue to the fascia cover- 

 ing the right iliacus muscle. In 

 this case the caecum is compara- 

 tively fixed ; but in other in- 

 stances the peritoneum surrounds 

 it almost entirely, and forms a 

 duplicature behind it, called 

 meso-ciuum. 



Coming off from the inner and 

 back part of the c^cum, at its 

 lower end, is a narrow, round, 

 and tapering portion of the in- 

 testine, named tiie appendix cccci, 

 or appendix vermifcr mis (figs. 

 270, 271). The width of this 

 process is usually about that of a 

 large quill or rather more, and 

 its length varies from three 

 to six inches, these dimensions 

 differing much in different cases. 

 Its general direction is upwards 

 and inwards behind the caBcum ; 

 and after describing a few slight 

 turns it ends in a blunt point. 

 It is retained in its position by a 

 small fold of peritoneum, which 

 forms its mesentery. The ctecal 

 appendix is hollow as far as its extremity : and its cavity communicates 

 with that of the crecum by a small orifice, sometimes guarded by a 

 valvular fold of mucous membrane. 



So far as is known, this appendix is peculiar to man and certain of 

 the higher apes, and to the wombat; but in some animals, as in the 

 rabbit and hare, the distal part of the caecum, being diminished in 



Fig. 270. — Stomach and Intestines. 



cc, cseciim ; AC, ascending ; tc, transverse ; 

 and DO, descending parts of the colon ; sf, 

 sigmoid flexure ; R, rectitm. 



