CAVITY OF THE ABDOMEN. 19 



the pelvis ; while in females, the uterus and its appendages are 

 situated between this intestine and the bladder. 



In the posterior part of the abdomen, in contact with the 

 spine, is the aorta. This great blood-vessel passes from the 

 thorax between the crura of the diaphragm, and continues down 

 the spine until it approaches the margin of the pelvis, when it 

 divides into two great branches called the Iliac Arteries. Each 

 of these great branches divides again, on the side of the pelvis, 

 into two ; namely, the External Iliac, which passes under the 

 crural arch to the thigh, and the Internal Iliac or Hypogastric 

 which descends into the cavity of the pelvis. 



Soon after the arrival of the aorta in the abdomen it gives off 

 two large branches. The first, which is called the Caliac, is 

 distributed to the liver, the stomach, and the spleen : the second, 

 called the Superior Mesenteric, is spent upon the intestines. 

 Lower down in the abdomen, it also sends off a small branch 

 for the intestines, called Inferior Mesenteric. Besides these 

 vessels for the chylopoietic viscera, the aorta sends off a large 

 branch, called Emulgent, to each kidney. 



The inferior or ascending vena cava is situated on the right 

 of the aorta, in front of the spine. It is formed below by the 

 union of the iliac veins, and in its progress upwards, it receives 

 the emulgent veins, which correspond to the arteries of the 

 kidneys ; but it receives in its course no veins which correspond 

 directly with the coeliac and mesenteric arteries. The smaller 

 veins that answer to the branches of these arteries, unite and 

 form one large vein, which goes to the liver, and' is called 

 (from the part of that viscus at which it enters,) Veiia Porta- 

 rum. From the liver three large veins pass into the vena 

 cava, and deposit there the blood of the vena portarum, after 

 it has furnished materials for the secretion of bile. The vena 

 cava, in its passage upwards, is in close contact with the 

 posterior thick edge of the liver : it often passes along a deep 

 groove in this edge, and sometimes it is completely surrounded 

 by the liver in its course. The veins of the liver enter the 

 vena cava at this place, and of course they are not to be seen 

 without dissection. Immediately after leaving the liver, the 



