1. UEQ: What happens to your food after you eat it? WarmUP: What are the major organs of the digestive system? The Digestive System

2. Digestion Function: Breakdown of food into a useable form that your cells can use!

3. Where does the digestive system start and end? Mouth Pharynx esophagus stomach small intestine large intestine (also called the colon) rectum anus

4. Enzymes help speed up the changing of food into a usable form Fats, proteins and carbs must be broken down by enzymes Vitamins, Minerals and water do not have to be broken down.

5. II. Trip through the Digestive System 1. Mouth 2. Esophagus 3. Stomach 4. Small Intestine - pancreas - liver - gallbladder 5. Large intestine 6. Anus

6. 1. Mouth: Where food enters Time spent: Few minutes Production of saliva is the first step in digestion (sometimes before you even start eating) Tongue moves it around and the saliva lubricates the food for easier chewing and swallowing. Teeth cause only a mechanical change. Saliva also contains an enzyme called amylase –chemically break down certain carbohydrates

7. MOUTH Where digestion starts Primary parts: –Lips: Sensory organ to judge texture and temp. –Cheeks –Tongue: Harbors the taste buds and mixes food. –Palate –teeth

8. Taste bud location Taste bud location.

9. 2. Pharynx Tube connecting mouth to the esophagus As you swallow the epiglottis covers the windpipe so food does not go down the wrong tube. Lasts a few seconds No digestion occurs here (just swallowing)

10. 3. Esophagus Tube connecting pharynx to stomach Few seconds No digestion occurs here Peristalsis (muscle contractions) send the food down the tube until it reaches the sphincter (start of the stomach) Esophagus video

11. Motor function of Digestive Tract Mixing movements: when smooth muscles contract rhythmically -ex: when stomach is full, waves of Propelling movements/Peristalsis : push contents through the system http://vimeo.com/2595338

12. 4. Into the Stomach Next stop: the stomach! Time spent: 4 hours Physical change: mixes and churns the food Chemical change: –Gastric juices: 2 enzymes - Pepsin and Rennin –Acid that breaks down food and bacteria Function: Stores and processes food.

13. Chemical change in the stomach Pepsin: breaks down protein Rennin: enzyme that turns milk into cheese (breaks down dairy) Let’s view the stomach!Let’s view the stomach!

14. 5. Through the Small Intestine Most digestion and absorption of nutrients into bloodstream occurs here! 18-39 feet long on average... The small intestine itself does not make enzymes, but 3 other organs (pancreas, liver, gallbladder) not in the digestive tract deliver enzymes to the small intestine Time: 12 hours to digest and absorb

16. The Pancreas The pancreas produces 3 enzymes Lipase: breaks down fats Protease: Breaks down protein Amylase: Breaks down carbs Delivers these enzymes to small intestine pancreas is a small flat organ that is located behind the stomach and start of small intestine

17. The Liver: Largest organ of the body (except the skin) Makes bile: BILE:BILE: Green, smelly liquid Breaks fats into smaller fat droplets Delivers the bile to the gallbladder for storage liver is the body's 'detoxifier‘ Plays a role with the kidney in the urinary system too.

18. The GallBladder Stores Bile Delivers the bile when needed to the small intestine If the bile hardens it forms gallstones. small (10 cm long) pear- shaped organ that is located near the start of the small intestine and the liver.

19. How are nutrients absorbed? Absorption: movement of chemicals into or out of an organ by diffusion, facilitated or active transport Has villi on the inside that have blood vessels that carry nutrients throughout the body

20. How the organs all work together:

21. 6. Large intestine Once in the large intestine: digestion is already complete. Large intestine only removes water from undigested food and begins to produce feces. Time: 4 hours 3 parts: Ascending (up) Transverse (across) Descending (down) Also contains: cecum, appendix, colon and rectum

22. 7. Anus Where waste is excreted: opening through which stools/feces (ie, the waste products of digestion) pass out of the rectum and are eliminated from the body nervous system triggers the urge to pass stools. surrounded by very strong sphincter muscles contract and expand to open the anus and allow stools to pass

23. Problems of Digestive System

24. Heartburn Lower esophageal sphincter opens too often or does not close tight enough, stomach acid can reflux, or seep, into the esophagus and cause the burning sensation. Caused by eating too much food Take an antacid such as rolaids, tums, pepto-bismol or prescription medications

25. Gallstones Block pathways for digestion Bile stores up and hardens either in the liver or the gallbladder have to have them surgically removed

26. ULCERS Sore or hole on inside the stomach or small intestine causes a burning feeling. Enzymes eat away at stomach lining Stress can bring on an ulcer or it is just natural production of too much acid Prescribed medicine for extreme cases Minor cases can uses Pepsid AC

27. Appendicitis Swelled appendix Causes severe pain on lower right side of body Bacteria builds up from stuck food Appendectomy – the removal of the appendix

28. Constipation Too much water is absorbed by the large intestine Can be a virus or something one eats Over the counter medicines usually take care of the problem Milk of Magnesia, eating more roughage (lettuce), prescription medications.

29. Not enough water is absorbed by the large intestine causing runny stools Caused by bacteria or virus or something one ate Some people have diarrhea often as part of irritable bowel syndrome or other chronic diseases of the large intestine. Over the counter medicines such as Pepto- Bismol, Imodium A-D, and Kaopectate Diarrhrea