Question

Give two reasons to explain why the absorption of digested food occurs mainly in the small intestine.

Answer 1

1. Absorption of digested food occurs mainly in the small intestine because it has finger-like projections called villi, which help in the absorption of food into the blood. Villi contain a lymph capillary called a lacteal in the centre. Lacteal, in turn, is surrounded by a network of thin and small blood vessels called blood capillaries close to its surface.
2. As the food moves slowly between, over and around the villi, the surface of the villi absorbs the digested food materials into the blood flowing through them. Blood, in turn, carries the absorbed food materials to all the parts of the body.
3. In the cells, food is used for energy, repair and growth. The process is known as assimilation.