[ 2c6 ] [Book IX, 



CHAP. XVII. 



THE CAVITY OF THE ABDOMEN. 



Contents of the Abdomen. Parts involved by the Peritoneum, Parti 

 not involved by it.- The Peritoneum, I* be Mefenterj.~7he Omen- 

 turn. Different in Man and Quadrupeds. 



THIS cavity is bounded above by the diaphragm, 

 below by the bones of the pelvis, at the fides 

 by various mufcles and the falie ribs, before by the 

 mufdes of the abdomen, and behind by the vertebras 

 of the loins and the os facrwru Strictly fpeaking, 

 however, no part is faid to be within the cavity of the 

 abdomen, which is not involved in a thin tranfparent 

 membrane, called the peritoneum, of which a more 

 particular defcription will prefently be fubmitted to 

 the reader* 



The parts which are involved in the peritoneum 

 are, the mefentery, the omentum or caul, the ftomach, 

 the fmall and great inteftines, the lacteal veffels, the 

 paqcreas, the fpleen, and the liver. 



The organs which are not involved in the perito- 

 neum> but are placed behind it, are the kidneys, the, 

 ureters, the receptacle of the chyle, the aorta, and the 

 vena c.iva. 



The upper part of the bladder is involved in the pe- 

 ritoneum, the lower is placed without it. 



The peritoneum is to be confidcred as a membrane 

 forming an internal covering to the parts which are 

 the boundaries of the abdomen, and at the fame time 

 doubled back on itfclf infuch a manner as to form the 

 external covering of the abdominal vifcera. 



TJie internal iiirface of the peritoneum is fmooth, 



its 



