The human digestive system consists of the alimentary canal and its associated glands.

The organs which are responsible for ingestion,digestion, absorption,assimilation and engestion constitute the digestive system.

PERISTALTIC MOVEMENTS,this movement helps in pushing the food in digestive tube.

The rhythmic contraction of the muscles lining the alimentary canal in order to push the food forward in a regulated manner along the digestive tube so that it can be processed properly in each part is known as peristaltic movements and these occur all along the gut.

DIGESTION IN MOUTH ,the process of digestion of food starts from mouth like chewing, grinding and swallowing of food.

When we eat only food, the first step is crushing of this food by our teeth and also mixing it with saliva. The saliva contains an enzyme called salivary amylase that breaks down starch which is a complex molecules to give sugar. The food is also wetted to make its passage through the alimentary canal smooth.

DIGESTION IN STOMACH, digestion of food complete in the stomach of human beings.

It lies below the diaphragm on the left side of abdominal cavity and is J-shaped. The food is stored and partly digested in the stomach.

The gastric glands present in the wall of the stomach release hydrochloric acid,a protein digesting enzyme called pepsin and mucus.

The hydrochloric acid creates an acidic medium which facilitates the action of the enzymes pepin.The acid also kills the harmful bacteria present in the stomach.

The mucus protects the inner lining of the stomach from the action of the acid under normal conditions. The exit of food from the stomach is regulated by a sphincter muscle which releases it in small amounts into the small intestine.

DIGESTION IN SMALL INTESTINE, small intestine contains digested food after the completion of digestion of food

The small intestine is the site of the complete digestion of carbohydrates, proteins and fats. It receives the secretions of the liver and pancreas for this purpose.

Role of Liver ,Liver performing different significant activities like secretion of bile juice.

  1. The bile juice from liver makes the food alkaline for the pancreatic enzymes to act as the food coming from the stomach is acidic.
  2. Bile salts break the large fat globular into smaller globules increasing the efficiency of enzyme action.

Role of Pancreas ,Pancreas play a vital role in different metabolic activities in body

The pancreas secrets pancreatic juice which contains enzymes like trypsin for digesting proteins and lipase for breaking down emulsified fats.

The walls of the small intestine contain glands which secret intestinal juice. The enzymes present in it finally convert the proteins to amino acids,complex carbohydrates into glucose and fats into fatty acids and glycerol.


The end products of digestion of food are amino acids,glucose and fatty acids and glycerol.