Question

How does the human digestive system work step by step?

Answer 1

Digestive system:

1. Food that we eat needs to be broken into smaller pieces and then into simple compounds so that it can be absorbed by the body easily and used to produce energy.
2. This is called food digestion and all the organs that participate in it, form the digestive system.
3. The digestive tract and accessory glands are the main ones in the digestive system.

Step by step process:

1. Ingestion: Taking the food into the mouth is called ingestion. Here food is broken into smaller pieces by the teeth and mixed with the saliva by the movement of the tongue. Carbohydrate is partially digested by salivary amylase.
2. Mixing and movement: The food is swallowed by the movements of the oesophagus. It moves through the oesophagus and reaches into the stomach.
3. Secretion: Many glands like the liver, pancreas and other glands in the wall of the stomach secrete enzymes, acids and other fluids that help in digestion.
4. Digestion: In the stomach, some protein-digesting enzymes act and digest the food. 80% of food is digested in the small intestine.
5. Absorption: In the small intestine the nutrients from digested food are absorbed by the cells of its wall. Now, these nutrients are passed to the blood.
6. Excretion: The undigested food is excreted. It can be stored temporarily in the rectum.