2. DIGESTION OVERVIEW I. Process of digestion II. Trip through the Digestive System III. Problems of the digestive system ND-1

3. I. Process of Digestion A) Breakdown of food: Food is broken down by the digestive system. Digestion changes food into a usable form the cells can use.

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

5. Enzymes help speed up the changing of food into a usable form What is the digestive system? made up of the digestive tract—a series of hollow organs joined in a long, twisting tube from the mouth to the anus—and other organs that help the body break down and absorb food

6. 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.

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

8. 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

9. Chemical change in the mouth: amylase Contained in saliva (salivary glands) Breaks down sugar and starches (carbs) into smaller components Video

10. 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

12. TASTE LAB The brown color is where you should taste that particular taste.

13. 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)

14. 3. Esophagus Tube connecting mouth 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

15. Motor function of Alimentary canal (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

16. 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.

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

18. 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 not in the digestive tract deliver enzymes to the small intestine Time: 12 hours to digest and absorb

19. Three parts to the Small Intestine: Duodenum 1. Duodenum –Located at the junction of the stomach and the small intestine (Towards the top) 2. Jejunum –The middle section (main twisted part) of the small intestine. 3. Illeum 3. Illeum −The final portion of intestines. Contains vili for absorbing nutrients.

21. 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 through the pancreatic duct pancreas is a small flat organ (about 18-25 cm long) that is located behind the stomach and sits close to the duodenum

22. 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.

23. 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.

24. How are nutrients absorbed? Absorption: movement of chemicals into or out of an organ Has villi on the inside that have blood vessels that carry nutrients throughout the body

25. How the organs all work together:

26. 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

27. 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

28. Problems of Digestive System -Heartburn Acid moves into the esophagus Caused by eating too much food Many people get acid reflux disease Take an antacid such as rolaids, tums, pepto-bismol

29. Problems Of Digestive System -Gallstones Bile stores up and hardens either in the liver or the gallbladder Block pathways for digestion have to have them surgically removed

30. Problems of Digestive System ULCERS Sore or hole on inside the stomach or small intestine Caused by too much HCl & pepsin being produced Enzymes eat away at stomach lining Causes burning sensation in stomach 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

31. Problems of Digestive System -Appendicitis Swelled appendix Bacteria builds up from stuck food Causes severe pain on lower right side of body Appendectomy – the removal of the appendix

32. Problems of Digestive System 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 Pepto-bismol, eating more roughage (lettuce), etc.

33. Problems of Digestive System Diarrhea Not enough water is absorbed by the large intestine Runny stools Caused by bacteria or virus or something one ate Over the counter medicines such as pepto-bismol will help