Liver

The liver, an organ found in all vertebrates, is the largest organ in the human body, it is a spongy, reddish brown gland that lies just below the diaphragm in the abdominal cavity. It serves to metabolize Carbohydrates and store them as glycogen; metabolize lipids (fats, including cholesterol and certain vitamins) and proteins manufacture a digestive fluid, blue, filter impurities and toxic material from the blood; produce blood clothing factors; and destroy old, worn-out red blood cells.

Two large lobes, the right and the left, make up most of the liver; attached to the right lobe are the smaller quadrate and caudate lobes. The lobes are made up of lobules six sided cells arranged around blood vessels, bile ducts, lymph vessels, and nerves. Certain recticuloen-dothelial cells line these lobules and play a role in immunity.

Approximately three sides of each cell are in contact with a blood vessel, and three are adjacent to a bile duct. The bile manufactured by each lobule passes down a common duct, which connects to larger ducts that lead to the common hepatic duct. This ducts that lead to the common hepatic duct. This duct joint with the cystic duct of the Callbladder and enters the duodenum along with the pancreatic duct of Wirsung. In the intestines bile salts aid in emulsifying fats and enhancing the metabolism of fats and proteins.

The liver is a highly vascular tissue. It receives 25 percent of its blood from a hepatic artery. The other 75 percent of the blood supply comes from the portal vein, which transport digested nutrients and hormones from the intestines, hormones from the pancreas, and old red blood cells and bilirubin, a component of bile, from the spleen. Blood leaves the liver by the inferior vena cava, which goes to the heart.

The liver able to regenerate itself after being injured or diseased; if, however, a disease progresses beyond the tissue's capacity to regenerate new cells, the body's entire metabolism is severely affected. Two common liver diseases are Hepatitis (inflammation of the lobules) and Cirrhosis, or a scarring of the lobules. Many disorders can affect the liver and Kupffer cells, and the bile ducts. Bile consists of such substances as lecithin, blue salts, and cholesterol, the last two of which can form Gallstones under certain conditions and result in obstruction of bile ducts. Jaundice, a yellow skin discoloration, is a symptom of a variety of liver disorders. Liver cancer is fairly rare but generally incurable. Severely impaired livers are sometimes replaced.