398 



USES OF THE LIVER DUCTLESS GLANDS. 



Vasa Aberrantia. In the livers of old persons, and occasionally in the 

 adult, certain vessels are found ramifying on the surface of the liver, but 

 always opening into the biliary ducts, which have been called vasa aberrantia. 

 These are never found in the foetus or in children. They are appendages of 

 the excretory system of the liver, and are analogous in their structure to the 

 ducts, but are apparently hypertrophied, with thickened, fibrous walls, and 

 present in their course irregular constrictions not found in the normal ducts. 

 The racemose glands attached to them are always very much atrophied. 



Gall-bladder, Hepatic, C'ystic and Common Ducts. The hepatic duct is 

 formed by the union of two ducts, one from the right and the other from 

 the left lobe of the liver. It is about an inch and a half (38 mm.) in length 

 and joins at an acute angle with the cystic duct, to form the ductus coin- 

 munis choledochus. The common duct is about three inches (76 mm.) in 

 length, of the diameter of a goose-quill, and it opens into the descending 

 portion of the duodenum. It passes obliquely through the coats of the in- 

 testine, and opens into its cavity, in connection with the principal pancreatic 



20 12 19 



FIG. 135. Gall-bladder, hepatic, cystic and common ducts (Sappey). 



1, 2, 3, duodenum ; 4, 4, 5, 6, 7, 7, 8, pancreas and pancreatic ducts ; 9, 10, 11, 12, 13, liver ; 14, (jail-blad- 

 der ; 15, hepatic duct ; 16, cystic duct ; 17, common duct ; 18, portal vein ; 19, branch from the coeliac 

 axis ; 20. hepatic artery ; 21, coronary artery of the stomach : 22, cardiac portion of the stomach ; 

 23, splenic artery ; 24, spleen ; 25, left kidney ; 26, right kidney ; 27, superior mesenteric artery and 

 vein ; 28, inferior vena cava. 



duct. The cystic duct is about an inch (25 mm.) in length, and is the 

 smallest of the three canals. 



The structure of these ducts is essentially the same. They have a proper 

 coat formed of ordinary fibrous tissue, a few elastic fibres and non-striated 

 muscular fibres. The muscular tissue is not sufficiently distinct to form a 

 separate coat. The mucous membrane is always found tinged yellow with 



