Each part of the human digestive system plays an important role in processing the food you eat. When you digest a meal, such as a slice of pizza, you become a seething mass of enzymes, chemicals, and muscle contractions.

Digestion and absorption are two distinct body functions. Digestion is the breakdown of foods into nutritional components that the body can use. An example of this is the breakdown of the cheese in your pizza into amino acids. Absorption is the transport of digested food (nutritional components, such as amino acids, fatty acids, and monosaccharides) to where it is needed in the body.

This tutorial concentrates on digestion of food in the human body. This tutorial will take you through the breakdown of food (digestion), but not absorption.