Human digestion palak soni x b biology project work s.a.i. f.a. i
Download as PPTX, PDF3 likes597 views
The document summarizes the key stages and functions of the human digestive system. It describes the two main types of digestion as mechanical and chemical. It then outlines the main organs that make up the gastrointestinal tract - from the mouth down to the rectum - and their roles in mechanically and chemically breaking down food. The small intestine is highlighted as the primary site of nutrient absorption into the bloodstream.
Human digestion palak soni x b biology project work s.a.i. f.a. i
- 3. Types › Mechanical (physical) Chew Tear Grind Mash Mix › Chemical Enzymatic reactions to improve digestion of Carbohydrates Proteins Lipids
- 4. • Gastrointestinal (Gl) tract – Tube within a tube – Direct link/path between organs – Structures • Mouth • Pharynx • Esophagus • Stomach • Small intestine • Large Intestine • Rectum
- 5. Teeth mechanically break down food into small pieces. Tongue mixes food with saliva (contains amylase, which helps break down starch). Epiglottis is a flap-like structure at the back of the throat that closes over the trachea preventing food from entering it.
- 6. Approximately 10” long Functions include: 1. Secrete mucus 2. Moves food from the throat to the stomach using muscle movement called peristalsis If acid from the stomach gets in here that’s heartburn.
- 7. J-shaped muscular bag that stores the food you eat, breaks it down into tiny pieces. Mixes food with digestive juices that contain enzymes to break down proteins and lipids. Acid in the stomach kills bacteria. Food found in the stomach is called chyme. 7
- 8. Small intestines are roughly 7 meters long Lining of intestine walls has finger-like projections called villi, to increase surface area. The villi are covered in microvilli which further increases surface area for absorption.
- 10. Nutrients from the food pass into the bloodstream through the small intestine walls. Absorbs: › 80% ingested water › Vitamins › Minerals › Carbohydrates › Proteins › Lipids • Secretes digestive enzymes
- 11. About 5 feet long Accepts what small intestines don’t absorb Rectum (short term storage which holds feces before it is expelled).
- 12. Functions › Bacterial digestion Ferment carbohydrates Protein breakdown – Absorbs more water – Concentrate wastes
- 13. Not part of the path of food, but play a critical role. Include: Liver, gall bladder, and pancreas
- 14. Directly affects digestion by producing bile › Bile helps digest fat • filters out toxins and waste including drugs and alcohol 14
- 15. Stores bile from the liver, releases it into the small intestine. Fatty diets can cause gallstones
- 16. Produces digestive enzymes to digest fats, carbohydrates and proteins Regulates blood sugar by producing insulin