DISSECTION OF THE ABDOMEN. 



343 



of the lobule it joins a larger vessel — the sublobular vein. By the 

 union of these sublobular veins throughout the liver, the larger 

 hepatic venous trunks are formed ; and these, as already seen, enter 

 the posterior vena cava in the anterior fissure of the liver. 



The Hepatic Artery is a branch of the cceliac axis. It enters the 

 liver with the portal vein, and ramifies with it. It has three sets of 

 branches: (1) capsular branches, to the tunica propria; (2) vaginal 

 branches, to Glisson's capsule and the vessels within it ; and (3) inter- 

 lobular branches, whose capillaries pass into the lobule, where they 

 help to form the intralobular 

 plexus, and enter the central 

 vein. The capillaries of the 

 vaginal and capsular branches 

 terminate in veins that join 

 the portal vessels. 



The Liver Cells. — These 

 are polygonal, granular cells. 

 They are arranged in columns 

 between the radial strands 

 of the intralobular plexus of 

 capillaries. 



The Bile Passages begin 

 within the lobule as a net- 

 work of fine canals — the bile 

 capillaries — tunnelled at the 

 lines of apposition of the liver 

 cells. At the periphery of the lobule these become continuous with 

 interlobular bile ducts having a proper wall and a simple cubical or 

 short columnar epithelial lining. The interlobular bile ducts unite to 

 form the larger ducts that accompany the blood-vessels in the portal 

 canals, and these finally form the main bile duct, which passes in the 

 gastro-hepatic omentum to perforate the wall of the duodenum. 



Fig. 47. 



Transverse Section through the Hepatic 

 Lobules ( Turner), 

 i. i. i. Interlobular veins ending in the intralobular 

 capillaries ; c. c. Central veins joined by the intra- 

 lobular capillaries. At a. a. the capillaries of one 

 lobule communicate with those adjacent to it. 



STRUCTURE OF THE SPLEEN. 



The spleen, like the liver, possesses two coats, viz., an outer serous or 

 peritoneal coat, and a deeper fibrous tunic, or tunica propria. The latter 

 is composed of white fibrous tissue with a considerable admixture of 

 elastic and non-striped muscular fibres. It detaches from its inner 

 surface a multitude of trabecule, which by their anastomosis form a 

 fibrous framework in the interior of the organ. The interspaces of 

 this framework are occupied by a grumous material — the splenic pulp. 

 If the cut surface of the spleen be washed beneath a tap, the pulp may 

 be removed and the fibrous trabecule rendered very evident. 



