1. DIGESTIVE SYSTEM & ENZYME NOTES

2. DIGESTIVE SYSTEM Includes mouth, pharynx, esophagus, stomach, small intestine and large intestine; several major glands and their secretions, including the salivary glands, the pancreas and the liver Digestion is the breakdown of food into simpler molecules that can be absorbed and used by the cells of the body

3. DIGESTIVE SYSTEM THE PROCESS OF DIGESTION: 1. Mouth - teeth break up food in a process called mechanical digestion; also salivary glands secrete the first digestive enzymes (amylase and mucous) 2. Pharynx - the top part of the throat; no digestion takes place here 3. Esophagus - the muscles of the esophagus begin to contract in waves, pushing food toward the stomach; this is called peristalsis

4. DIGESTIVE SYSTEM 4. Stomach - three secretions combine to form the gastric fluid: Mucous - keeps food lubricated and protects walls of the stomach Hydrochloric acid - helps break down food Pepsin - mixes with hydrochloric acid to begin digesting proteins The food is churned for several hours becoming a pasty mixture known as chime

5. DIGESTIVE SYSTEM 5. Small Intestine - the chime is flooded with enzymes from three sources: Duodenum (1 st part of small intestine) - releases enzymes that continue digesting Pancreas - releases pancreatic fluid that digests carbohydrates, proteins and fats Liver - secretes bile, which is stored in the gallbladder, which breaks down fats further

6. DIGESTIVE SYSTEM 5. Small Intestine - the now mostly digested food passes through the rest of the small intestine where nutrients are absorbed into the bloodstream; when it leaves the s.i., the food is nutrient free 6. Large Intestine (Colon) - main job is to remove water from undigested materials passing through it 7. Rectum – store feces (solid waste)

7. Mouth Pancreas Salivary Glands Pharynx Esophagus Liver Stomach Tongue Large Intestine Small Intestine Appendix RectumAnus Stomach Pancreas Gallbladder Liver