50 ORGANS OF DIGESTION AND ALIMENTARY TRACT. 
What is the blood supply of the liver ? 
It is supplied by the hepatic artery and the portal vein. The vein 
carries the bulk of the blood passing to the liver. 
How do these vessels terminate in the liver? 
They divide and subdivide, and, surrounded by tne connective 
tissue of Glisson’s capsule, ramify through the liver structure in the 
spaces between the lobules; hence they are called the interlobular 
vessels. The terminal branches of the vein and artery break up into 
capillaries which pass through the liver lobules between the radiating 
rows of hepatic cells, and pour their blood finally into the vein, which 
is in the centre of each lobule. 
What is the vessel occupying the centre of a liver lobule called ? 
It is called the intra-lobular vein, and is the beginning radicle of 
the hepatic veins which are formed by the union of these intra-lobular 
veins. Through these the blood is conveyed away from the liver. 
How are the lymphatic vessels distributed to the liver ? 
They form an abundant network in the capsule and accompany the 
bloodvessels in the patches of Glisson’s capsule in the interlobular 
spaces or spaces between the lobules. These vessels are connected 
with minute lymph spaces within the lobules. Small, irregular nodules 
of lymphoid tissue occur in the interstitial tissue of the liver. 
Describe the origin of the gall passages. 
The intra-lobular gall passages begin between liver-cells within the 
lobules. They have no walls of their own, but are simple channels 
grooved in the walls of contiguous liver-cells. They never come. in 
contact with the blood capillaries, being separated from them by at 
least one row of liver cells. As these bile capillaries pass out to the 
interlobular spaces they unite to form small bile ducts lined with flat- 
tened, polygonal-shaped cells. These small bile ducts unite to form 
the larger gall passages which are lined with a distinct mucous mem- 
brane. 
PANCREAS. 
Describe the structure of the pancreas. 
It is a racemose gland, resembling the salivary glands in structure. 
The alveoli, however, instead of being saccular, are tubular in form. 
The cells lining these alveoli are columnar or polyhedral in shape. 
The connective tissue of the gland is arranged more loosely than in the 
salivary glands. 
