The human digestive system breaks down food into smaller particles through a series of organs so they can be absorbed and distributed to nourish the body. It consists of the oral cavity, esophagus, stomach, small intestine, large intestine, liver, pancreas, and other glands. Food is ingested, broken down mechanically and chemically, absorbed, and waste is eliminated through complex muscular movements and secretions of enzymes from various organs.

1. HUMAN DIGESTIVE SYSTEM Celeste Roderno-Desingaño

2. -System with complex tubes of considerable length -Also called the alimentary tract -This group of organs that break down food into smaller particles or molecules -This breakdown makes it possible for the smaller digestive particles to pass through the intestinal wall into the bloodstream - Particles are then distributed to nourish all parts of the body Digestive System

3. Parts of the Digestive System

4. 1. Oral Cavity - this is where food is mixed with the saliva secreted by several sets of salivary glands - Saliva dissolves and softens food and acts as a lubricant, facilitating swallowing and passage through the next portions of the digestive tract. Parts of the Digestive System

5. Teeth - This is where food is broken into smaller pieces by both biting and chewing. Tongue - manipulates the food during chewing and forms it into a mass called bolus , in preparation for swallowing. -Pushes the bolus through a cavity called the pharynx and into esophagus. Parts of the Digestive System

6. 2. Esophagus - a long tube running through the throat and thorax and connecting to stomach in the upper portion of the abdominal cavity. Peristalsis – contraction movement of esophagus muscle Sphincter – special ring of muscle found on the junction between esophagus and stomach, which when contracted closes the entrance to the stomach. Parts of the Digestive System

7. Peristalsis in the Esophagus

8. 3. Stomach - This is a large muscular sac, which functions as a storage organ, making discontinuous feeding possible. Rugae – folds of the stomach that increases its surface area. - churns the food, mixing it with the gastric juice Gastric Juice – contains enzymes that break down protein Chyme -soupy mixture that leaves the stomach and passes through the pyloric sphincter into the small intestines. Parts of the Digestive System

10. 5. Large Intestines - also known as colon - Reabsorbs much of the water used in the digestive process and excretes certain salts, such as those of calcium and iron. Caecum – this is a small and functionally unimportant for human Appendix – finger-like process found at the tip of the caecum Feces – undigested food excreted into the colon and eliminated from the body. Rectum – Last portion of the large intestines that functions as a storage chamber for the feces until defecation Parts of the Digestive System

16. Digestive Flow ORAL CAVITY ESOPHAGUS STOMACH SMALL INTESTINE LARGE INTESTINE RECTUM ANUS