What is digestion ? Types of digestion. In biology

What is digestion ? Types of digestion. In biology:- Break down the complex components of the food into simple absorbable molecules is called digestion. Food is digested in the alimentary canal at three places-

What is digestion ? Types of digestion. In biology
What is digestion ? Types of digestion. In biology
  • Buccal cavity
  • stomach
  • Intestine.

Digestion in buccal cavity:-

Digestion of food starts from the buccal cavity, where food is held for 15-18 second before swallowing the food act as a stimulant for taste, touch and thermal receptors present on the mucous membrane of the buccal cavity. The nerve impulse generated in these receptors reach nerve centers secretion of saliva, chewing and swallowing by reflex stimulation.

There are two types of buccal cavity of digestion

Digestion in stomach:-

Presence of gastric folds in the stomach makes the stomach makes the stomach very elastic and distensible, therefore it acts like a silo. When food reches stomach, its muscles start relaxing leading to its distension. it is called receptive relaxation. Due to this food accumulates in the stmoch and remains there for 2-5 hours. stomach also exhibits two types of digestion:-

  • Mechanical digestion
  • Chemical digestion

Digestion in intestine:-

Partially digested food is finally digested and adsorbed in the intestine. Perisataltic movements start throughout the small intestine as soon as food reaches in it. Due to these movements, chyme is propelled forward in small intestine. Enzymes also throughly mix due to these movements.