UPPER MESENTERIC VESSELS. 439 



The suspensory or falciform ligament is placed between the upper con- 

 vex surface of the liver and the parietes of the abdomen. It is triangular 

 in shape, with its base forwards. The lower border is concave, and is 

 attached to the liver ; whilst the upper border is convex, and is connected 

 to the abdominal wall, on the right side of the linea alba, and to the under 

 part of the diaphragm. In its base or free part is the remains of the um- 

 bilical vein, which is named the round ligament. 



This fold allows the umbilical vein to reach the liver without piercing 

 the peritoneum ; and with a little care the dissector will be able to detach 

 the serous membrane from the vein, and to trace it on each side into the 

 suspensory ligament. 



The coronary ligament is a short but wide process of the peritoneum, 

 which connects the hinder part of the liver to the diaphragm. It reaches 

 all across the liver, but at each side it is enlarged, and forms a triangu- 

 larly-shaped piece ; to these larger portions of it the terms right and left 

 lateral ligaments have been applied. 



The left lateral ligament is attached to the liver above the edge of the 

 left lobe, and is formed by two pieces of peritoneum, which are in contact; 

 it lies in front of the oasophagean opening in the diaphragm. 



The right lateral ligament lies deeply in the hypochondriac region, in 

 front of the vena cava inferior : it consists of two pieces of peritoneum not 

 touching each other. 



MESENTERIC VESSELS AND SYMPATHETIC NERVE. 



Directions. The vessels and nerves (mesenteric) which are distributed 

 to the greater part of the alimentary tube, may be first dissected. After 

 these have been examined, and the connections of the aorta and vena cava 

 have been learnt, most of the intestine can be taken out to give room for 

 the display of the viscera in the upper part of the abdomen. 



MESENTERIC VESSELS. The superior and inferior mesenteric arteries 

 are two large branches of the aorta, which supply the intestine, except a 

 part of the duodenum and the lower end of the rectum. Each is accom- 

 panied by a vein, and by a plexus of the sympathetic nerve. 



Dissection (fig. 143). For the dissection of the superior mesenteric 

 vessels and nerves, the transverse colon and the great omentum are to be 

 placed on the margin of the ribs, and one layer (anterior) of the mesen- 

 tery is to be removed. Whilst tracing the branches of the artery to the 

 small intestine, corresponding veins, and offsets of the sympathetic nerve 

 on the arteries, will be met with ; these last are removed in cleaning the 

 vessels. Mesenteric glands and a few lacteal vessels will come into view 

 at the same time. 



The branches from the right side of the vessel to the large intestine are 

 to be next followed : and after all the branches have been cleaned, the 

 trunk of the artery should be traced back beneath the pancreas. The 

 plexus of surrounding nerves should be also defined. 



The superior mesenteric artery (fig. 143, a) supplies branches wholly 

 to the small intestine beyond the duodenum, and to half the large intes- 

 tine, viz., as far as the end of the transverse colon. 



Arising from the aorta near the diaphragm, the vessel is directed down- 

 wards between the layers of the mesentery, forming an arch with the con- 

 vexity to the left side, and terminates in offsets to the caecum and the end 

 of the small intestine. At first the artery lies beneath the pancreas and 



