476 LABORATORY MANUAL OF HUMAN ANATOMY 



formis. It may pass in front of the ileum, then giving a special 

 form and disposition to the meso-appendix. The fourth branch 

 passes to the left along the ileum. 



The following arteries may occasionally be derived from the 

 superior mesenteric : 



(1) Hepatic artery (A. hepatica), or right branch of the proper hepatic 



(ramus dexter arteriae hepaticae propriae). The importance of 

 the anomalous origin of these arteries will be discussed when the 

 dissection of the hepatoduodenal ligament is made. 



(2) Cystic artery (A. cystica). 



(3) Coronary left gastric artery, or artery of stomach (A. gastrica 



sinistra). 



(4) Left colic artery (A. colica sinistra). 



(5) Superior hemorrhoidal (A. haemorrhoidalis superior). 



What relation does the superior mesenteric artery bear to 

 the omphalomesenteric artery in the embryo? Does MeckePs 

 diverticulum, when present, receive any branches from this 

 artery ? 



Superior Mesenteric Vein (V. mesenterica superior) and its Tribu- 

 taries. (Vide Spalteholz, Fig. 497.) 



This vein accompanies the artery. Follow its course until it 

 joins the splenic vein (V. splenica). 



The following tributaries may be found : 



(a) Intestinal veins (Vv. intestinales) . 



(b) Right gastro-epiploic vein (V. gastro-epiploica dextra). 



(c) Pancreatic veins (Vv. pancreaticae) . 



(d) Ileocolic vein (V. ileocolica). 



(e) Right colic veins (Vv. colicae dextrae). 



(f) Middle colic vein (V. colica media). 



(g) Pancreaticoduodenal veins (Vv. pancreaticoduodenales) . 

 (h) Duodenal veins (Vv. duodenales). 



Where the intestine is applied directly to the posterior abdominal wall 

 without the interposition of peritoneum, an anastomosis is established 

 between the systemic and portal circulations. These anastomoses have 

 been well established in pathological cases. What do you understand by 

 the veins of Retzius ? 



Superior Mesenteric Plexus (Plexus mesentericus superior). (Vide 

 Toldt, Fig. 1332.) 



A dense plexus of sympathetic nerves surrounds the superior 

 mesenteric artery, and filaments from it accompany the different 

 branches of the artery to the gut. Dissect out carefully these 

 filaments and determine whether they join in the spaces between 



