Question

What is the difference between ingestion and digestion?

Answer 1

Hint: The \[5\] stages of nutrition include ingestion, digestion, absorption, assimilation and egestion. These are the fundamental metabolic processes of the human body. They occur in distinct areas of the body such as the mouth, stomach, duodenum, ileum and large intestine. The food is taken by the mouth and digested in the stomach. The nutrients from the food are absorbed by the duodenum and the wastes are excreted through the large intestine and anus.

Complete explanation:
The major differences between ingestion and digestion are given in the table below.

Ingestion	Digestion
Ingestion is the taking of food into the body.	Digestion is the breaking down of food into small molecules.
It takes place in the mouth.	It takes place in the stomach.
Mechanical digestion occurs here.	Chemical digestion occurs here.
Mechanical digestion increases the surface area of food facilitating their chemical digestion by stomach.	Chemical digestion helps in absorption of nutrients from the alimentary canal.
Food taken by the mouth is broken down to small pieces with the help of teeth and saliva.	Digestion is done with the help of stomach and pancreatic enzymes. Stomach acid also plays an important role.
Enzymes that help in ingestion are salivary amylase, lipase, lysozyme and kallikreins.	Enzymes that help in digestion are pepsin, trypsin, protease, amylase and nuclease.
The ingested food passes down to the stomach through the oesophagus for digestion.	The digested food passes to duodenum for absorption.

Note:
Absorption comes after digestion. The nutrients from the food are absorbed into the bloodstream of the body. It occurs through diffusion in the wall of the small intestine. The next step, assimilation is the process of nutrients being absorbed by the cells of the body in the form of energy. The waste products from the food are excreted out from the body through the large intestine and anus.