#Liver

#Biology

#Organ

Introduction

• The liver is a vital organ with a wide range of functions, including detoxification, protein synthesis, and the production of bile, which is necessary for digestion.

• The bile produced by the liver is essential for the digestion of fats. Bile is formed in the liver and either stored in the gallbladder or released directly into the small intestine.

• The liver normally weighs between 1.3—3.0 kilograms and is a soft, pinkish-brown organ. It is the second-largest organ in the body, and is located on the right side of the abdomen.

• The liver plays a major role in metabolism and has a number of functions in the body, including glycogen storage, plasma protein synthesis, and drug detoxification. It also produces bile, which is important for digestion.

• The liver is supplied by two main blood vessels on its right lobe: the hepatic artery and the portal vein. The portal vein brings venous blood from the spleen, pancreas, and small intestine so that the liver can process the nutrients and byproducts of food digestion.

• The bile produced in the liver is essential for the digestion of fats. Bile is formed in the liver, and it is stored in the gallbladder or released directly into the small intestine. After being stored in the gallbladder, the bile becomes more concentrated than when it left the liver; this increases its potency and intensifies its effect in digesting fats.

Functions

• The liver is thought to be responsible for up to 500 separate functions, usually in combination with other systems and organs.

• The various functions of the liver are carried out by the liver cells or hepatocytes.

• The liver is the mainstay of protein metabolism— it synthesizes as well as degrades. It performs several roles in carbohydrate and l

• Lipid metabolism. The bulk of the lipoproteins are synthesized in the liver.

• n the first- trimester fetus, the liver is the main site of red blood cell production. By the 32nd week of gestation, the bone marrow has almost completely taken over that task.

• The liver also produces the insulin -like growth factor 1 (IGF-1), a polypeptide protein hormone that plays an important role in childhood growth and continues to have anabolic effects in adults.

• The liver stores a multitude of substances, including glucose (in the form of glycogen), vitamin A (1–2 years’ supply), vitamin D (1–4 months’ supply), vitamin B12 (1–3 years’ supply), iron, and copper. The liver is responsible for immunological effects, acting as a sieve for the antigens that are carried to it via the portal system.

• The liver synthesizes angiotensinogen, a hormone that is responsible for raising blood pressure when the angiotensinogen is activated by renin, an enzyme that is released when the kidney senses low blood pressure.

• The liver breaks down or modifies toxic substances, such as alcohol and most medicinal products, in a process called drug metabolism.

• This sometimes results in toxication, when the metabolite is more toxic than its precursor.

  Preferably, the toxins are conjugated to avail excretion in bile or urine. The liver breaks down insulin and other hormones.