Human Digestive System

Segmentation contractions occur in the large intestine and small intestine.

MMC stands for Migrating Motor Complexes that are waves of electrical activity that sweep through the intestines in a regular cycle during fasting.

It is an enzyme that conducts proteolysis, i.e. begins protein catabolism by hydrolysis of the peptide bonds. It is used in the manufacturing of detergent.

The process of digestion is facilitated by the release of digestive juices from some organs of the body. Pancreas, liver, small intestine and stomach are the organs which aid in digestion by releasing digestive juices. In large intestine, digestion does not take place because no juice is released by it to act upon food.

 Grass-eating animals eat fibrous food, which takes longer time to digest. That is why, they are also called ruminants. To digest the cellulose, they have a large sac-like structure between small intestine and large intestine. 

The food absorbed by blood needs to be transported to each and every organ of the body in order to be used to build the complex substances required by the body. This process is known as assimilation.

The digested food is absorbed by blood to provide energy. The digestion of food is completed in small intestine and then absorption of food starts with the help of numerous small finger-like projections present in the small intestine known as villi.

The food, which is not digested in the body of amoeba, is left as residue and expelled out of the body. 

In buccal cavity, there is no protein-digesting enzyme. In oesophagus, no digestion takes place at all. The digestion of proteins starts in the stomach due to the release of a protein-digesting enzyme called pepsin.

Stomach is a large J-shaped organ of alimentary canal, which is the widest part of the digestive tract. Large intestine, oesophagus and rectum are narrower and tube-like structures. 

Small intestine  is the principal site of carbohydrate digestion. Pancreatic and intestinal juices present in the intestine have all the enzymes required for carbohydrate digestion.

Pepsin is secreted by gastric glands and hydrolyses protein into proteoses and peptones.

Bile juice creates the alkaline pH in intestine for the action of pancreatic lipase. Thus, enzymes work more effectively in the intestine.

Lysozyme is an anti-bacterial enzyme present in saliva which destroys bacteria.

Chyme is the thick, acidic and semi-fluid mass of partly digested food that is passed from the stomach to the duodenum.