Physiology of the liver
The liver produces bile at between 6 to 1000 ml/day and excretes it through the bile cannaliculi which are drained into the bile ducts and then into the cystic duct and gall bladder or directly into the duodenum through the common bile duct. Hence part of the test of liver function includes the production of bilirubin. Also the liver takes part in the conjugation of substances some which then become less toxic for the body. If it fails then it is unable to conjugate these substance which then enter the blood stream and act as toxicants and toxic agents which then cause hepatic encephalopathy.
Blood function of the liver
The liver receives large amount of blood from both the hepatic artery and the portal vein. It is able to receive the blood and its content to include large amounts of hormones from the gastrointestinal tract which helps the digestive and other metabolic functions of the liver, failing which the liver undergoes fatty degeneration. The liver also functions as reservoir of blood. It also has large amounts of lymphatic flow through the spaces of Disse. High amount of hepatic vascular pressures lead to formation of ascites.
Liver is capable of regenerating itself after damage or injury or infection as in hepatitis. Hepatocyte growth factor is the main factor which stimulates the cell division in the hepatocytes that lead to regeneration. The process of regeneration ends when the liver has reached its full size.
Liver kuppfer cell macrophagic system
The liver functions as a blood cleansing system by which its macrophages called Kupffer cells remove debris and foreign bodies, mostly colonic bacilli from the blood system. They also breakdown red blood cells and metabolic end product of hemoglobulin breakdown which is bilirubin. Liver assists the excretion of bilirubin into bile for its elimination and also the excesses of cholesterol.
Metabolic functions of liver
Liver lobule. Click to restart
School of Medicine
Creator: Oluwole Ogunranti