The main organs participating in digestion

The main organs participating in digestion

Liver

Liver

This is the largest gland of the human body. Its weight is approximately 1 : 5-2 kilogram.
» Bile is secreted through liver only. This bile accelerate the reaction of enzymes present in the intestine.
» Liver convert excess of amino acid into ammonia by deamination. These ammonia are further converted into urea by ornithine cycle. Urea comes out from body through kidney.
» Liver converts some quantity of protein into glucose during deficiency of carbohydrate.
» In carbohydrates metabolism liver converts the excess of glucose found in blood into glycogen and stores it into hepatic Cell as reserve nutrients. If the necessity of glucose arises the liver convert reserve glycogen into glucose. Thus, it regulates the quantity of glucose in the blood.
» In case of decrease of fat in food liver converts some of the parts of the carbohydrates into fat.
» The production of fibrinogen protein takes place by liver which helps in clotting of blood.
» The production of Heparin protein takes place in liver which prohibit the clotting of blood inside the body.
» The dead RBC is destroyed by the liver only.
» The liver reserve some quantity of iron, copper and vitamin.
» It helps in regulating the body temperature.
» Liver is an important clue in investigating a person's death that has been due to poison in food.

Gall Bladder

Gall bladder is a pear shaped sac, in which the bile coming out of liver is stored.
» Bile comes into the duodenum from gall bladder through the bile duct.
» Secretion of bile into the duodenum takes place by reflex action.
» Bile is a yellowish-green coloured alkaline liquid. Its pH value is 7.7.
» The quantity of water is 85% and the quantity of bile pigment is 12%.

The Main functions of bile are as under:
1. It makes the medium of food alkaline so that pancreatic juice can worked.
2. It kills the harmful bacteria coming with food.
3. It emulsifies the fats.
4. It accelerates the bowel movement of intestine by which digestive juices in the food mix well.
5. It is helpful in the absorption of vitamin K and other vitamins mixed in fats.
In case of obstruction in bile duct, liver cells stop taking bilirubin from blood. As a result, bilirubin spreads throughout the body. This is called jaundice.

Pancreas

This is the second largest gland of the human body. It acts as simultaneously endocrine and exocrine type of gland. » Pancreatic juice secretes out of it in which 9.8% water and the remaining parts contain salt and enzymes. It is alkaline liquid, whose pH value is 7.5 - 8.3. It contains the enzymes which can digest all the three types of food materials (like carbohydrates, fat and protein), therefore it is called complete digestive juice.

Islets of Langerhans

This is a part of the Pancreas
» It was discovered by the medical scientist Langerhans.
» From its β cell- insulin, from α cell-glucagons and from δ cell- somatostaintin hormones are secreted.

Insulin

It is secreted by β -cell of islets of Langerhans.
» Glucagon is secreted by α -cell and somatostatin harmone is secreted by δ -cell of islets of langerhans.
» It was discovered by Banting and Best in the year 1921.
» It controls the process of making glycogen from glucose.
» Diabetes is caused due to the deficiency of insulin.
» Excessive flow of insulin causes Hypoglycemia in which one loses the reproducing capacity and vision deterioration.

Glucagon

It re-converts the glycogen into glucose.

Somatostatin

This is a polypeptide hormone which increases the duration of assimilation of food.