nutrient A nutrient is a substance needed for the body to develop and function properly. 6 MAJOR CLASSES OF NUTRIENTS 1. water - "The" essential for all body functions” 2. carbohydrates - "go" foods 3. fats - concentrated "go" foods 4. proteins - "grow" foods 5. vitamins - "glow" foods 6. minerals - "glow" foods

digestion Breakdown of food small enough to be used by the body.

peristalsis Muscle contractions that move food through the digestive system

mechanical digestion Breakdown of food by motion or movement. For example, chewing in the mouth or churning food in the stomach.

chemical digestion Breakdown of food into the molecules of nutrients that can be used by the body. This takes place through the addition of chemicals and enzymes throughout the digestive organs.

mouth Where all digestion begins. Both mechanical digestion (chewing) and chemical digestion (saliva) take place in the mouth

esophagus Tube through which all food passes to enter the stomach. It takes food about 7 to 8 seconds to be pushed through the esophagus by muscle contractions know as peristalsis.

stomach In the stomach the largest portion of mechanical digestion takes place. Food is churned and mixed until it has broken down into a consistency much like that of a milkshake. There are also strong acids like hydrochloric acid that begin to break down the foods that are made up of proteins.

small intestine The small intestine is where the majority of chemical digestion takes place. Chemicals and enzymes from the pancreas, liver, and gall bladder break the chemical bonds of the food that is moving through the small intestine until the molecules are small enough to be absorbed into the blood stream to be delivered to the cells.

absorption Villi are finger-like pieces of tissue. The purpose of these wrinkles and projections is to increase surface area for absorption of nutrients. Each villus is covered in microvilli, which increase the surface area manyfold. Each villus contains a lacteal and capillaries. The lacteal absorbs the digested fat into the lymphatic system which will eventually drain into the circulatory system. The capillaries absorb all other digested nutrients.microvillilactealfatlymphatic systemcirculatory systemnutrients

largelarge intestine

liver

gallbladder

pancreas

elimination

enzymes