Digestion and Absorption

Digestion Digestion-The bodily process of breaking food down into simpler compounds the body can use. The Digestive Tract- a tube, about 30 feet, that extends from the mouth to the anus. It contains the esophagus, the stomach, and the small and large intestine. These parts work together to both mechanically and chemically help the body use food.

The Digestion Process 2 phases- Mechanical and Chemical Mechanical- Begins in the mouth. 1.Teeth chew and break down food. 2.Contractions of the muscular walls of the digestive tract carry on the mechanical action. These contractions mix food particles and break them into smaller pieces. 3.Waves of contraction, peristalsis, the muscles push food through the digestive tract. * Emotions such as sadness, depression and fear can slow this process down. Anger and aggression can speed up this process.

The Digestion Process Chemical Phase- 1.Also begins in the mouth. As you chew food is mixed with saliva, an enzyme-containing liquid. Saliva moistens the food partials and begins to break down starches. 2.In the stomach, gastric juices containing hydrochloric acid are secreted. These juices break down food further. * Carbohydrates leave the stomach first, Proteins are second, followed by fats. As a result you will feel hungry sooner after a meal high in Carbs.

The Digestion Process 3. Next the food leaves the stomach and enters the small intestine. Here several juices intestinal, pancreatic, and bile break down the food. 4. Then indigestible residues, bile pigments, other waste and water travel into the large intestine. The large intestine acts as a storage area. Eventually the body will excrete these material in the feces.

The Absorption Process The body can absorb water, ethyl alcohol, and simple sugars directly from the stomach. They pass through the stomach walls and into the bloodstream. However, most absorption takes place in the small intestine through capillaries.