Where is the bile produced? Which component of the food does it help to digest?

AcademicBiologyNCERTClass 7

The liver secretes bile juice. It gets stored in the gall bladder.

Bile performs two major functions:
(i) It makes the acidic food coming from the stomach alkaline so that the pancreatic enzymes can act on it.
(ii) The bile salts break down the fats present in the food into small globules making it easy for the enzymes to act and digest them.


Digestion of Food in Humans:
1. Digestion begins when food enters the mouth (oral cavity). Teeth are used to grind and break up food. This is called physical or mechanical digestion. 
2. An enzyme in saliva called amylase begins to break down into maltose sugar. This is called chemical digestion
3. After it is swallowed, the chewed food moves down the esophagus. The esophagus acts as a connection between the mouth and the stomach.
4. The bolus (the chewed food coming from the mouth) then reaches the stomach, where mechanical and chemical digestion takes place further. The muscles in the stomach walls churn the bolus allowing it to mix with digestive enzymes and gastric acids like HCl. This process converts the bolus into a liquid called chyme.
The digestion in the stomach continues for several hours. During this process, an enzyme called pepsin breaks down most of the protein in the food. The chyme is slowly transported into the small intestine, where most chemical digestion takes place.
5. Liver produces bile juice which is stored in the gall bladder.
6. Bile juice is released from the gallbladder to help digest fats.
7. Enzymes from the pancreas and intestinal walls combine with the chyme. 
8. Most of the nutrients are absorbed in the small intestine. Nutrients are absorbed through its walls into the circulatory system and by the time the chyme exits the small intestine, only water, and indigestible substances are left behind.
9. The chyme then enters the large intestine, where water is removed and bacteria break down some indigestible materials, producing important compounds (such as vitamin K). The concentrated waste material that remains is called feces, which is passed into the rectum and eliminated from the body through the anus.
raja
Updated on 10-Oct-2022 12:46:21

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