What is liver and function of liver
What is liver and function of liver :- Liver or hepar is the largest gland of the body and weight about 1500 gm in an adult human liver is comparatively larger at the time of the birth and forms about 5 percent of the total body weight but in adults it forms just 2 percent of the body weight.
Liver is situated in the right upper side of the abdominal cavity just below the diaphragm. it is bilobed and the right lobe is much biggest than the left lobe. Both the lobes are connected by a sickle shaped falciform ligament. There is an oval blue colored sac like structure, measuring about 8 cm in length attached to the lower surface of the right lobe through mesentery. This sac is called gall bladder. A cystic duct arises from the narrower end of the gall bladder which unites with common hepatic duct to form common bile duct.
Histology of the liver:-
Each lobe of the liver is covered by a fibroelastic serous coat, called capsule. There are man lobules in each lobe which are separated from each other in some mammals like pigs, by thin layers of connective tissue. These are termed as glison’s capsule.
In human being there is no distinct boundary between lobules of the liver therefore, liver parenchyma appears hexagonal in the centre of which there is a branch of hepatic vein called central vein. Hepatocytes having 6 to 8 surface are arranged around central vein in one to two cell thick, soil anastomosing radial cords. Each liver cell has one or two large nuclei having variations in their size.
Cytoplasm of these cells also show variation due to different amount of suspended glycogen and fats. there is a network of narrow, irregular lacunae called hepatic sinusoids, between hepatic cords. These sinusoids are larger than blood capillaries and lined by a thick coat of cells having two types of cells- typical endothelial cells and fixed macrophages called kupffer cells. kupffer cells eat dead red blood cells and bacteria.