320 



DISSECTION OF THE ABDOMEN. 



Aorta lies 

 on front of 

 spine : 



parts 

 around. 



Vena cava 

 inferior : 



extent : 



relations; 



is by the 

 side of the 

 aorta, 



except 

 above. 



Arteries 

 crossing it, 



and vein. 



its upper end of the vein can be better observed after the dissection 

 of the vessels of the liver. 



The AOETA (tig. 138, p. 363) enters the abdomen between the 

 pillars of the diaphragm, and finally divides into the common iliac 

 arteries opposite the fourth lumbar vertebra. At its beginning 

 the vessel lies somewhat to the left of the middle line ; and it 

 commonly inclines slightly inwards as it descends. 



In the abdomen the aorta is covered at first by the pancreas, then 

 by the third part of the duodenum, and for a short distance below 

 that by the peritoneum. Beneath the pancreas it is crossed by the 

 splenic vein above the superior mesenteric artery, and by the left 

 renal vein below that vessel ; and the solar and aortic plexuses of 

 the sympathetic lie along its anterior surface throughout. It rests 

 on the lumbar vertebrae, with the pillars of the diaphragm embracing 

 it at the beginning. To its right side is the vena cava. Its relation 

 to other deep parts cannot be examined at present. 



The INFERIOR VENA CAVA begins opposite the fifth lumbar 

 vertebrae by the union of the common iliac veins, and reaches thence 

 to the heart. 



The venous trunk is placed on the front of the vertebral column, 

 to the right of the aorta (fig. 138). It lies close to the aorta, and is 

 concealed by the duodenum and pancreas as high as the cms of the 

 diaphragm ; but above that spot it is inclined away from the artery, 

 and ascending in front of the diaphragm, is embedded in the back of 

 the liver for about an inch and a half. Lastly, it leaves the abdomen 

 by an aperture in the tendinous centre of the diaphragm, on the 

 right of, and higher than the aortic opening. 



Its relations with vessels are not the same as those of the aorta, 

 Beneath it are the right lumbar, renal, capsular, and diaphragmatic 

 arteries ; and crossing over it below the kidney is the right spermatic 

 artery. Superficial to it beneath the pancreas is the beginning of the 

 portal vein. 



REMOVAL OF THE INTESTINES. 



Dissection. The jejunum, the ileum, and the whole of the large 

 intestine, as far as the lower part of the pelvic colon, are now to 

 be removed. Place two ligatures on the jejunum, one at the duodeno- 

 jejunal flexure and another an. inch further on, and divide the 

 bowel between them. In the same way divide the lower part of the 

 pelvic colon between a double ligature. The whole of the intestine 

 between these points is then removed by cutting through its 

 peritoneal attachment close to the bowel wall. Care should be 

 taken not to cut into the bowel, and in removing the transverse 

 colon the arteries of the stomach must be avoided. 



After removal, ligature the ileum about six inches from the ileo- 

 colic junction and divide it above the ligature. Proceed then in the 

 following manner : 



1. Cut off the upper four inches of the jejunum and the lower four 

 inches of the ileum above the cut, and put them aside in a tray in water. 



