Functions

• Breaks down food into molecules the body can use.
• Molecules are absorbed into blood and carries throughout body.
• Waste is eliminated from body.

There are 3 processes that occur: digestion, absorption, and elimination.

Digestion

• Process by which body breaks down food.
• Mechanical: food physically broken down, chewing.
• Chemical:chemicals produced by the body break foods into smaller chemical building blocks, Almost ALL chemical digestion takes place in the small intestine.
• Mouth, stomach, salivary glands, esophagus, tongue, teeth, small intestine

Absorption

• Process by which nutrient molecules pass through the wall of digestive system into blood.
• Almost all absorption of nutrients takes place in the small intestines.

Elimination

• Any material that is not absorbed is eliminated (removed) from the body as waste.
• Large intestine: water that enters is absorbed into the bloodstream and the rest of the materials is readied for elimination.
• End of LI is short tube called rectum: waste is compressed into solid form. Eliminated from body through anus, muscular opening at end of rectum.