Digestion system

Digestion is the process of converting large and complex molecules into simpler forms, which are small molecules that are easier to digest by the human body. 

The purpose of the digestive system: to bring essential nutrients into the internal environment so that they are available to each cell of the body
Mechanisms of Digestion:
Ingestion—food is taken in
Digestion—breakdown of complex nutrients into simple nutrients
Motility -of gastrointestinal (GI) wall—physically breaks down large chunks of food material and moves food along the tract
Secretion -of digestive enzymes allows chemical digestion
Absorption—movement of nutrients through the GI mucosa into the internal environment
Elimination—excretion of material that is not absorbed
Regulation—coordination of the various functions of the digestive system