THE INTESTINES. 407 



influence of the hepatic, pancreatic, and intestinal secretions, that are 

 carried on those molecular transformations which properly constitute the 

 digestive function. It is also in this intestine that the absorption of the 

 nutritive principles and fluids commences, and in which the villi are the 

 essential organs. 



2. The Large Intestine. 



The large intestine commences by a vast reservoir in the form of a cul- 

 de-sac, named the ccecum. It is continued by the colon, whose posterior 

 extremity is succeeded by the rectum. It is separated from the small 

 intestine by the ileo-ccecal valve. 



A. Ccecum. (Figs. 204, 205, 206.) 



Situation Direction. This is a very wide and elongated sac, occupying 

 the right hypochondriac, where it affects an oblique direction downwards 

 and backwards. 



Dimensions Capacity. Its length is ordinarily a little over three feet, 

 and it will contain, on an average, about 7J gallons of fluid. 



Form External surface. The elongated sac formed by the caecum is 

 conical in shape, terminating in a point inferiorly, and bulging and curved 

 like a crook superiorly. Externally, it exhibits a great number of circular 

 furrows, interrupted by longitudinal muscular bands, four of which are 

 observed in the middle portion of the organ ; they disappear towards its 

 extremities. The bottom of these furrows necessarily corresponds to the 

 internal ridges, and these can be made to disappear by destroying the 

 longitudinal bands, which considerably lengthens the caecum ; thus showing 

 that these transverse puckerings are due to the presence of the riband-like 

 cords, and have for their object the shortening of the intestine without 

 diminishing the extent of its surface. 



Relations. To study its relations, the caecum is divided into three 

 regions : 



1. The superior extremity, base, arch, or still better, the crook, presents 

 in the concavity of its curvature, which is turned forwards, the insertion of 

 the small intestine and origin of the colon. Placed in the sublumbar 

 region, it responds, superiorly, to the right kidney and to the pancreas, 

 through the medium of an abundant supply of connective tissue. Outwardly, 

 it touches the parietes of the right flank, and is encircled by the duodenum. 

 On the inner side, it adheres by cellular tissue to the termination of 

 the large colon, and is in contact with the convolutions of the small 

 intestine. 



2. The middle portion (meso-ccecum} is in contact, inwardly, with the same 

 convolutions and the large colon ; outwardly, with the cartilages of the false 

 ribs, whose curvature it follows. 



3. The inferior extremity, or point, usually rests on the abdominal pro- 

 longation of the sternum; but as it is free and can move about in every 

 direction, it often happens that it is displaced from this situation. 



Mode of attachment. The csecum is fixed to the sublumbar region and 

 the terminal extremity of the large colon by a wide adherent surface. 

 All around this surface the peritoneum, which constitutes the serous 

 covering of the csecum, is gathered into folds, and in passing from the 

 caecum to the origin of the colon, this tunic forms a particular short and 

 narrow fraenum designated the meso-ccecum. 



