THE PAXCREAS 



987 



gland to tlie spleen; it is situated transversely across the vertebral cnhnun uitli the 

 large vessels intervening. 



The anterior ■wrfarc is in ('(^itaet with tlu' stoniaeh, whieli organ gives a. eon- 

 cavity to the surface (fig. ">5J0). This surface is covered l)y peritoneum derived 

 from the ascending layer of the transverse meso-colon. 



The posterior surface is in contact with the crura of the diaphragm, the aorta, 

 and superi(jr mesenteric vessels, which structures are interposed l:)etween it and tiie 

 spine (figs. 571, 586). The splenic artery and vein run lengthways above the hack 

 of the upper border of the i)osterior surface. To the left, the posterior surface is in 

 contact with the left kidney and suprarenal capsule. The upper border in the 

 middle line abuts against the crcliac axis. 



The inferior surface is navYow , and lies over the fourth part of the duodenum and 

 beginning of the jejunum. The transverse meso-colon is continued from the front 

 of the head along the border sc^parating this surface from the anterior surface. The 

 splenic end of the transverse colon lies under the left extremity of this surface. 

 From the under surface of the transverse meso-colon a layer of peritoneum passes 

 to the central part of the inferior surface. The posterior surface is devoid of 

 peritoneum. 



The tail of the pancreas is the name given to the left extremity of the organ; 

 it touches the lower part of the inner surface of tlie spleen. 



Fig. 587. — The Pancreas and its Duct. 



duct of pancreas duct of pancreas 





COMMON BILE DUCT 



The duct of the pancreas, or the canal of ^^'irsung, white in appearance, runs 

 from nearly the extreme left of the gland, concealed by the proper substance of the 

 pancreas, nearer its posterior surface than the anterior, between the upjter and lower 

 l)orders, to empty into the lower and inner part of the second ])ortion of the duo- 

 denum with the common bile duct. It runs sinuously, receiving its branches as it 

 goes, which enter nearly at right angles. These branches are straight. Its diam- 

 eter near its termination is one-tenth of an inch. The pancreatic duct often does 

 not join the common bile duct until its termination, running side l\v side with it 

 through the walls of the intestine. Occasionally the pancreatic duct opens by itself 

 into the duodi-num. 



Blood-supply. — The i)ancreas receives l>lood from the splenic artery through 

 its })ancreatic liranches. and from the superior mesenteric and hepatic Ity the infe- 

 rior and superior ])ancreatico-duodenal arteries, which form a loop running round, 

 below, and to the right of its head. 



The blood is return<'d into the jiortal vein by means of the splenic an<l superior 

 mesenteric veins. 



Lymphatics. — TIk^ lymjihatics terminate in two glands whii-h lie on the 

 superior mesenteric artery. 



Nerves. — These are branches of the solar plexus which accomiianv the arteries 

 enterinir the trland. 



