2. Digestion Digestion is the process of breaking food down into molecules small enough for the body to absorb. Digestive system

3. Types of Digestion Mechanical Digestion The physical breakdown of food by teeth in the mouth, and muscles in the stomach. Chemical Digestion The breakdown of fats, proteins, and complex carbs into smaller units by enzymes.

4. The Mouth Mechanical digestion begins

5. Chemical Digestion within the Mouth (cont.) The salivary glands produce Amylase. Starch is digested into its monomer glucose.

6. Esophagus A muscular tube that connects the mouth to the stomach. Peristalsis: Involuntary waves of muscle contractions that push food toward the stomach. Mucus: is a thick slippery substance produced by the body. It helps make food easier to swallow. Peristalsis

7. The Stomach Digestive juice contains the enzyme PEPSIN. Pepsin chemically digests the proteins in your food, breaking them down into amino acids. Digestive juice also contains hydrochloric acid. This acid helps break down food and kills many of the bacteria that enters your body. The stomach also produces mucus, which coats and protects the lining of your stomach.

8. The Stomach Most mechanical digestion takes place in the stomach. Three layers of muscles mixes food with digestive juices in a churning motion. As you eat your stomach will expand between 1-2 liters to hold the food you eat.

9. The Stomach continued Note ( If over time to much acid continually builds up in the stomach a ulcer may occur.)

10. The Small Intestine The small intestine is about 35 - 40 feet long. Almost all chemical digestion and absorption of nutrients take place in the small intestine. The small intestine contains millions of tiny finger shaped structures called villi.

11. Digestion of Lipids (fats)

12. Absorption Is the process by which nutrient molecules pass through the wall your digestive tract and into the circulatory system.

13. The Liver The largest and heaviest organ inside the body. The liver produces bile, a substance that breaks up fat molecules. Bile flows from the liver to the gallbladder, after you eat the gallbladder passes bile into the small intestine.

14. The Pancreas The pancreas is a triangular organ that lies below the small intestine. It produces enzymes that help break down starches, proteins and Fats.

15. The Large Intestine The last section of the digestive system. All the remaining water is absorbed into the bloodstream. The remaining material is readied for elimination. The large intestine ends in a short tube called the rectum. The material is compressed into solid form. The waste material is eliminated from the body through the anus.