Tag: Absorption

Animals eat to grow, repair etc. They simply eat to live. In this unit we will study how animals make use of what they eat.

Ingestion is the taking of substances such as food and drink into the body through the mouth. Mechanical digestion is the breakdown of food into smaller pieces without chemical change to the food molecules. Chemical digestion is the breakdown of large insoluble molecules into small soluble molecules. Absorption is the movement of small food molecules and ions through the wall of the intestine into the blood. Assimilation is the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells. Egestion is the passing out of food that has not been digested or absorbed, as faeces, through the anus.

After the completion of the digestion of food in the ileum by the action of intestinal juice secreted by the small intestinal wall, food is converted into a state in which it can be absorbed into the blood stream.