How does the liver do its job?

Answer 1

Functions of Liver1: Regulation of blood glucose level

When the blood glucose concentration becomes excessive; liver converts the glucose into glycogen. Liver converts the glycogen back to the glucose when energy is needed.

2: Metabolism

Liver is responsible for the metabolism of proteins and fats. It synthesizes blood clotting factors and stores various types of vitamins.

3:Bile secretion

The hypatocystes (cells) of liver secrete bile. The bile is stored in gallbladder.The bile duct of liver and cystic duct of gallbladder form common bile duct. The common bile duct join the pancreatic duct, the bile from common bile duct and pancreatic juice from pancreatic duct empty into duodenum (of small intestine) through the sphincter of oddi (valve) if it is opened. The opening of this valve is controlled by a hormone called Cholecystokinin.

Bile juice helps in emulsificaton of fats.

Bile is alkaline solution. Its molecules have dual nature (one end is attracted to water molecule while other is attracted to fat molecule). Thus its molecules remain in between water molecules and fat molecules (emulsification process).

If bile molecules were not present between fats and water, the fat molecules would be repelled by water molecules and be attracted to each other. The fat molecules would merge together because fats are insoluble in water. The merged fats would not be easily broken down with lipase (fat digesting enzyme).

4:Breakdown of old red blood cells

Liver breaks down the old red blood cells into bilurubin. Bilurubin is excreted in bile and urine.

5: Detoxification

Liver contains macrophages called Kupffer cells. These cells engulf and breakdown toxic matter such as microorganisms, dead cells and chemicals. Kupffer cells ingest microorganism by phagocytosis. The engulfed microorganism is called phagosome. Lysosmes in the cytoplasm of kupffer cell, fuse with the phagosome and release digestive enzymes. These enzymes breakdown and kill the microorganism.

But how does kupffer cell identify toxic matter?

There are receptors for the toxic matter on the surface of kupffer cells. The harmful particle and these receptors of kupffer cell can fit together like pieces of a puzzle. The harmful particle is then engulfed by kupffer cell.