Human Digestive System/Liver

The liver is the largest visceral organ and performs over 200 functions. Some of the main functions include:

• the metabolism of absorbed substances

- carbohydrate metabolism: synthesize and store glycogen when glucose levels become elevated and breakdown of glycogen when glucose levels drop below normal

- lipid metabolism: triaglycerides and cholesterol are released from the liver when blood levels drop

- amino acid metabolism: amino acids are synthesized into proteins or can be changed into glucose or lipids when there is demand for energy.

- vitamin and mineral storage: liver serves as a reservoir for most vitamins and minerals.

• blood regulation

- drug, waste product and toxin removal

- elimination of antibodies

- processing of hormones circulating in the blood like adrenal, thyroid, hormones, vitamin D, etc.

- makes plasma proteins such as albumin and clotting factors

- produces bile

The production of bile is important for digestion. Bile salts help emulsify fats by creating micelles (lipid like droplets). The formation of micelles creates a hydrophobic region inside the core and a hydrophilic region outside. Inside a micelle there are lipids and cholesterol and lipase enzymes secreted from the pancreas can break down triaglycerides into monoglycerides, fatty acids and glycerol. After this process, bile salts are recycled.

When the liver does not produce adequate bile salts to create micelles properly, cholesterol breaks off and causes gallstones