In human alimentary canal, name the site of complete digestion of various components of food. Explain the process of digestion.
Answers
mechanism of digestion:
(1) INGESTION
it is the process of intake of food by mouth food is moistened by saliva ,before swallowing masticated by teeth into smaller particles
(2) DIGESTION
the process of breaking down large organic molecule (like carbohydrates) into smaller ones (like sugars) is called digestion it is done with the help of some bio catalyst called enzymes
it is completed in the following steps:
* carbohydrates digestion initiates inside mouth satrch is converted into simple sugar by salivary amylase
*proteins are converted into peptones with the help of pepsin and renin
*emulsification of fats with the help of bile juice
*breakdown of emulsified fat by lipase
*formation of amino acid ,glucose ,fatty acids with the help of pancreatic juice and intestinal juice
(3) ABSORPTION
it is the process by which digested food passes from the alimentary canal into the blood all the digested food is taken up by the walls of intestine which has numerous finger like projection called Vikki and lacteals(small lymph capillary found in the villi of the small intestine) villi increase the surface area of absorption
(4) ASSIMILATION
it is the distribution of digested food products to various cells of the body
the villi in small intestine are richly supplied with blood vessels it take up the absorbed food to each and every cell of the body it is then utilised for obtaining energy building up new tissues and rpairingthe older ones
(5)EGESTION
the elimination of undigested food formed in the colon of the large intestine through anus is called EGESTION peristalsis gradually push the undigested food from small intestine to large intestine the remaining material after reabsorption of water and ions is stored in the rectum for sometime and is ultimately removed from the body through anus ☺
In small intestine, complete digestion of various components of food take place.
The process of digestion of food in mouth, stomach and small intestine in human body are as follows:-
Mouth:- Digestion of food begins in the mouth. Saliva present in mouth contains digestive enzyme, called salivary amylase, which breaks down starch into sugar.
Stomach:- Stomach stores and mixes the food received from the oesophagus with gastric juices. The main components of gastric juice are hydrochloric acid, mucus and pepsin.
Hydrochloric acid dissolves bits of food and creates an acidic medium for action of pepsin which digest protein and mucus protects the inner lining of the stomach from the action of HCL.
Small Intestine:- Small intestine is the site of complete digestion of Carbohydrates, proteins and fats. Small Intestine produces intestinal juice from the glands present on its wall. Intestinal juice helps in further digestion of food. Small intestine also obtains digestive juices from liver and pancreas that helps in mixing of food.
the liver produces bile juice that causes emulsification of fats and pancreas produces pancreatic juice for digesting proteins and emulsified fats. This digested food is finally absorbed through the intestinal walls.