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CHAPTER XXXIII. 



SECRETING GLANDS. OF THE PANCREAS. OF THE LIVER. THE 



LIVER IN INVERTEBRATA. LOBULES OF THE LIVER. PORTAL 



CANALS. PORTAL VEIN. HEPATIC ARTERY. HEPATIC DUCT. 



GALL BLADDER. HEPATIC VEIN. NERVES AND LYMPHATICS. 



LIVER CELLS. OF THE CONNECTION OF THE SMALLEST DUCTS 



WITH THE LIVER CELLS. OF THE PASSAGE OF THE BILE INTO 



THE DUCTS. OF THE QUANTITY AND USES OF THE BILE. 



Of the Pancreas. This is a large gland, placed across the spine, 

 behind the stomach, in physiological relation with the duodenum 

 or the first portion of the intestine. It is flattened from before 

 backwards. Its left extremity, or tail, tapers off towards the 

 spleen ; its right extremity, or head, is much larger, lying close 

 within the curve of the duodenum, and presenting a recurved 

 extremity following the lower portion of that intestine, and some- 

 times termed the lesser pancreas. The ordinary weight of the 

 pancreas, according to Cruveilhier, is from 2 to 2J ounces, but 

 may rise to 6 ounces. Its colour is gray, inclining to pink. 



The pancreas, like the salivary glands, is imbedded in areolar 

 tissue, and receives its blood from several neighbouring vessels. 

 Its arteries are derived from the splenic and hepatic branches of 

 the coeliac axis, and from the superior meseriteric. The blood is 

 -returned by the corresponding veins into the vena porta. Its 

 nerves come from the solar plexus. 



In structure, the pancreas appears to resemble the salivary 

 glands. It is subdivided into lobules separated by septa of areolar 

 tissue, which dip inwards from that which forms a common en- 

 velope to the whole gland. The lobules are subdivided into smaller 

 parts by similar, but less complete and more delicate inflections of 

 the areolar tissue; and these minute ultimate granulations or acini 

 of the gland, correspond to the terminal extremities of the com- 

 mon duct. The excretory duct is concealed within the substance 

 of the gland, and takes a course from the left to the right extre- 

 mity, receiving very numerous tributaries on its way, and thus 



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