332 



THE AXATOMY OF THE HORSE. 



tlie siihlolndar vein. By the xiuiou of these sublobular veins thi-oiigh- 

 <jut the liver, the lai-ger hepatk venous trunks are foi-med ; and these, 



as ah-eadj seen, enter tlie pos- 

 torit)r vena cava in the anterior 

 tissure of the liver. 



The Hepatic Artery is a 

 branch of the coiliac axis. It 

 enters the liver with the portal 

 vein, and ramifies with it. It 

 has three sets of branches : (1) 

 (xqjsida)' branches, to the tunica 

 propria ; (2) vaf/inal branches, 

 to Glisson's capsule and the 

 vessels within it ; and (3) inier- 

 ^^^- 41- lobular branches, whose capil- 



Traxsverhe Section through the Hepatic Lobules laries paSS intO the lobulc, 



i, i, i. Interlobular veinrending in the intralobular ''"''^^^^'^ t^^^y help tO fomi the 

 capillaries; c, c. Central veins joined by the intra- in+vilnhiilnr ii1pyii«! •mrl mi+pv 

 lobular capillaries. At a, o. the capillaries of one l»tialODUlai piCXUS, ana eutei 

 lobule coniniunicate with those adjacent to it. the Central Vein. TllC Capil- 



laries of the vaginal and capsular branches terminate in veins that join 

 the portal vessels. 



The Liver Cells. — These are granular nucleated masses of protoplasm, 

 often containing fat particles. They are arranged in columns between 

 the strands of the intralobular plexus of capillaries. 



The Bile Passages begin within the lobule as a network 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 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. 



structure of the spleen. 



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

 2)e7'itoneal 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 sur- 

 face a nuiltitude of trabeadce, which by their anastomosis ft)rm a fibrous 

 framework in the interior of the organ. The interspaces of this frame- 

 work 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 trabecula) rendered very evident. 



The S2)lenic Artery, a division of the cocliac axis, is a very large 



