THE LIVER. Ill 



the large. Its action is such that the distention of the coecum will 

 prevent the passage of air or fluids backwards into the small intes- 

 tine. (Fig. 93.) It is also called the valve of Bauhin of Morgagni, 



The colon is the longest portion of the large intestine ; it gra- 

 dually diminishes in diameter until it terminates in the sigmoid 

 flexure on the left side.^ (Fig« 92.) It ascends upon the right side, 

 and, forming an arch transversely, descends upon the left. 



The rectum is the terminating portion of the large intestine, and 

 reaches from the sigmoid flexure to the anus, occupying a position 

 in front of the sacrum. It is somewhat barrel-shaped, that is, is 

 larger in the middle than at either end. The peritoneal covering 

 is deficient below and behind. The muscular coat has a very great 

 thickness and redness. The external fibres are longitudinal, and 

 the internal are circular. The fibres of the external muscular 

 coat wind around the inferior edge of the circular coat, and terminate 

 in the mucous coat, which, in some measure, accounts for haemor- 

 rhoids and prolapsus ani. The mucous coat is thicker and redder 

 than in the upper part of the intestine, and at the lower extremity, 

 just above the anus, is thrown into a number of pouches between 

 the longitudinal muscular fibres. (Fig. 94.) About five or six inches 

 above the anus, is a semicircular fold of the mucous membrane on 

 each side of the rectum ; these two are about half an inch distant 

 from each other: they resemble the valvuloe conniventes, and in 

 some measure prevent the involuntary discharge of fseces. 



THE LIVER. 



The liver is the largest glandular organ in the body, and secretes 

 bile. It is oblong and oval in its shape, and occupies the right hy- 

 pochondriac, a portion of the epigastric and left hypochondriac 

 regions. It iveighs from four to five pounds ; measures from ten to 

 twelve inches transversely, and from six to seven antero-posteriorly ; 

 its greatest thickness is from four to five inches. It is convex upon 

 its upper surface, and concave upon its lower. Its colour is of a 

 reddish brown, with occasional spots of black. It is covered almost 

 entirely by peritoneum, which upon its upper surface, forms a broad 

 suspensory ligament,^ whexGhy i^ is held in contact with the dia- 

 phragm. In the anterior edge of this ligament, is another of a cord- 

 like character called ligame^itum teres,^ which was originally the 

 umbilical vein. It passes through the anterior notch of the liver 

 and umbilical fissure. Posteriorly, the two laminse of the suspen- 

 sory ligament diverge, forming the coronary ligatnent, under which 

 the liver is destitute of peritoneum. The lateral ligaments'^ ^ are 

 also peritoneal, being, in fact, a continuation of the coronary ; they 

 are horizontal and attach the rigl^t and left sides of the liver to the 

 posterior walls of the abdomen. There is a deep depression upon 



