ABDOMEN. 



G59 



brim of the pelvis. The muscles forming the boundaries of this cavity are lined 

 upon their inner surface by a layer of fascia, differently named according to the 

 part to which it is attached. 



This cavity contains the greater part of the alimentary canal, some of the 

 accessory organs 1 to digestion, the liver, pancreas, and spleen, and the kidneys 

 and supra-renal capsules. Most of these structures, as well as the wall of the 

 cavity in which they are contained, are covered by an extensive and complicated 

 serous membrane, the peritoneum. 



The apertures found in the walls of the abdomen, for the transmission of 

 structures to or from it, are the umbilicus, for the transmission (in the foetus) of 

 the umbilical vessels ; the caval opening in the Diaphragm, for the transmission 

 of the inferior vena cava ; the aortic opening, for the passage of the aorta, vena 

 azygos, and thoracic duct; and the cesophageal opening, for the oesophagus and 

 pneumogastric nerves. Below, there are two apertures on each side ; one for the 

 passage of the femoral vessels, and the other for the transmission of the spermatio 

 cord in the male, and the round ligament in the female. 



Regions. For convenience of description of the viscera, as well as of reference 

 to the morbid condition of the contained parts, the abdomen is artificially divided 

 into certain regions. Thus, if two circular lines are drawn round the body, the 

 one parallel with the cartilages of the ninth ribs, and the other with the highest 

 point of the crests of the ilia, the abdominal cavity is divided into three zones, an 

 upper, a middle, and a lower. If two parallel lines are drawn from the cartilage 

 of the eighth rib on each side, down to the centre of Poupart's ligament, each of 

 these zones is subdivided into three parts, a middle and two lateral. 



The middle region of the upper zone is called the epigastric (*, over, and 

 yaerrifp, the stomach)] and the two lateral regions, the right and left hypochondriac 

 (vrto, under, and ^ovSpot, the cartilages'). The central region of the middle zone 

 is the umbilical; and the two lateral regions, the right and left lumbar. The 

 middle region of the lower zone is the hypogastric or pubic region ; and the lateral 

 regions are the right and left inguinal. The parts contained in these different 

 regions are the following (fig. 331): 



Right Hypochondriac. 



The right lobe of the 

 liver and the gall-bladder, 

 the duodenum, hepatic 

 flexure of the colon, upper 

 part of the right kidney, 

 and right supra-renal cap- 

 sule. 



Right Lumbar. 

 Ascending colon, lower 

 part of the right kidney, 

 and some convolutions of 

 the small intestines. 



Right Inguinal. 

 The caecum, appendix 

 caeci, ureter, and spermatic 



vessels. 



Epigastric Region. 

 The middle and pylo- 

 ric end of the stomach, 

 left lobe of the liver and 

 lobus Spigelii, the hepa- 

 tic vessels, coeliac axis, 

 semilunar ganglia, pan- 

 creas, parts of the aorta, 

 vena cava, vena azygos, 

 and thoracic duct. 



Umbilical Region. 

 The transverse colon, 

 part of the great omen- 

 turn and mesentery, trans- 

 verse part of the duode- 

 num, and some convolu- 

 tions of the jejunum and 

 ileum. 



Hypogastric Region. 



Convolutions of the 

 small intestines, the blad- 

 der in children, and in 

 adults if distended, and 

 the uterus during preg- 

 nancy. 



Left Hypochondriac. 

 The splenic end of the 

 stomach, the spleen and 

 extremity of the pancreas, 

 the splenic flexure of the 

 colon, upper half of the 

 left kidney, and left su- 

 pra-renal capsule. 



Left Lumbar. 

 Descending colon, lower 

 part of left kidney, and 

 some convolutions of the 

 small intestines. 



Left Inguinal. 

 Sigmoid flexure of the 

 colon, ureter, and sper- 

 matic vessels. 



