THE ALIMENTARY APPARATUS. 



227 



pelvis, and. behind by the vertebral column, quadratus lumborum, 

 and psoas muscles. It is lined throughout by peritoneum, inclos- 

 ing the greater portion of the alimentary canal. It has six 

 openings, as follows : 



Aortic opening, for the vena azygos, aorta, and thoracic duct: 

 CEsophageal opening, for the oesophagus and pneumogastric nerves; 

 Quadrate opening, for the vena cava inferior; 

 Umbilicus, in front, for the foetal umbilical vessels; 

 Femoral canal (vide femoral hernia) ; 



Inguinal canal, for the round ligament in the female, and the sper- 

 matic cord in the male. 



KEGIONS OF THE ABDOMEN. For convenience of study, the 

 cavity of the abdomen is divided into nine regions by four imag- 

 inary lines, two circular lines drawn around the body, one at the 

 lower margin of the thorax (Leidy) or on a level with the car- 

 tilages of the ninth ribs, the second at the highest point of the 

 crest of the ilium; and two vertical lines, drawn from the car- 

 tilage of the eighth rib on each side through the centre of Pou- 

 part's ligament, or from the anterior inferior spinous process 

 of the ilium, drawn upward (Leidy). These regions are named 

 as follows : 



Right hypochondriac, 



Right lumbar, 



Right inguinal (iliac), 



Epigastric region, 

 Umbilical region, 

 Hypogastric region, 



Left hypochondriac, 



Left lumbar, 



Left inguinal (iliac). 



Hypochondriac. 



Hepatic flexure of 

 colon, right lobe of 

 liver, gall-bladder, and 

 upper part of right 

 kidney. 



RigJit Lumbar. 

 Greater part of right 

 kidney, ascending co- 

 lon, and portions of 

 the small intestine. 



Contents of Regions. 



Epigastric. 

 Left lobe of liver, 

 lobulus S p i g e 1 i i , 

 greater part of stom- 

 ach, duodenum, and 

 pancreas, portions of 

 the kidneys and su- 

 prarenal capsules, 

 vena cava, aorta, tho- 

 racic duct, semilunar 

 ganglia. 



Umbilical. 



Transverse portions 

 of colon and duode- 

 num, jejunum, and 

 ilcum, part of mesen- 

 tery and great omen- 

 turn, receptaculum 

 chyli, and portions of 

 both kidneys. 



Left Hypochondriac. 



Splenic flexure of 

 colon, spleen, tail of 

 pancreas, splenic end 

 of stomach, and upper 

 part of left kidney. 



L eft 



Part of left kidney, 

 descending colon, 

 some convolutions of 

 small intestine, and 

 part of the omentum. 



