introduction
Background information and introduction:
- The digestive system involves the digestive tract and several accessory organs, which function in catabolism by breaking down food into nutrient molecules that can be utilized by the body.
- The digestive tract consists of a long continuous tube that extends from the mouth to the anus.
- Main structures include the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. Within the mouth, the tongue and teeth participate as accessory structures. Other important organs such as the salivary glands, liver, gallbladder, and pancreas secrete fluids into the digestive tract to aid the process of retrieving nutrients for the body’s use.
- There are three main types of processes that food undergoes:
- Digestion
- Absorption
- Elimination
- Digestion and absorption occur in the digestive tract. Following their intake into the body, they become readily usable by cells in the body for metabolism to maintain their processes and functions.
- There are six main activities in which the digestive system prepares the nutrients for its uptake for body cells:
- Ingestion:
- Mechanical digestion
- Chemical digestion
- Movements
- Absorption
- Elimination