1. The Digestive System

2. How is food digested?

3. Digestion involves: Breaking down of food into smaller pieces Breaking down of food into smaller pieces The mixing of food The mixing of food Movement through the digestive tract Movement through the digestive tract Chemical breakdown of the large molecules of food into smaller molecules. Chemical breakdown of the large molecules of food into smaller molecules.

4. Describe the digestive system The digestive tract is a series of hollow organs joined in a tube from the mouth to the anus. Food passes through the digestive tract. The digestive tract is a series of hollow organs joined in a tube from the mouth to the anus. Food passes through the digestive tract. Accessory organs include the liver, gall bladder, and pancreas. Food does not pass through these organs. Accessory organs include the liver, gall bladder, and pancreas. Food does not pass through these organs.

5. Identify the organs of the digestive system

6. Identify and tell the function of each part of the digestive system MOUTH Mechanical Digestion: Teeth bite off and chew food into a soft pulp that is easy to swallow. Mechanical Digestion: Teeth bite off and chew food into a soft pulp that is easy to swallow. Chemical Digestion: Chewed food mixes with saliva: from salivary glands, to make it moist and easy to swallow. Chemical Digestion: Chewed food mixes with saliva: from salivary glands, to make it moist and easy to swallow.

7. Identify and tell the function of each part of the digestive system MOUTH Enzymes in the saliva begin digestion of carbohydrates into sugars. Enzymes in the saliva begin digestion of carbohydrates into sugars. Taste Buds: sweet, sour, bitter and salty Taste Buds: sweet, sour, bitter and salty Epiglottis: flap that covers the windpipe so food does not go down it when swallowing Epiglottis: flap that covers the windpipe so food does not go down it when swallowing

8. Identify and tell the function of each part of the digestive system ESOPHAGUS The esophagus is a muscular tube. It takes food from the throat and pushes it down through the neck, and into the stomach. The esophagus is a muscular tube. It takes food from the throat and pushes it down through the neck, and into the stomach. It moves food by waves of muscle contraction called peristalsis. It moves food by waves of muscle contraction called peristalsis.

9. Identify and tell the function of each part of the digestive system Stomach The stomach has thick muscles in its wall. These contract to mash the food into a water soup called chyme. The stomach has thick muscles in its wall. These contract to mash the food into a water soup called chyme. The stomach lining produces strong digestive juices which contain the enzyme call pepsin and hydrochloric acid. The stomach lining produces strong digestive juices which contain the enzyme call pepsin and hydrochloric acid.

10. Identify and tell the function of each part of the digestive system Stomach These create chemical reactions in the stomach, breaking down and dissolving its nutrients. These create chemical reactions in the stomach, breaking down and dissolving its nutrients.

11. Identify and tell the function of each part of the digestive system Small Intestine This part of the digestive tract is narrow, but very long - about 20 feet. This part of the digestive tract is narrow, but very long - about 20 feet. Most digestion takes place here Most digestion takes place here Enzymes continue the chemical reactions on the food. Enzymes continue the chemical reactions on the food.

12. Identify and tell the function of each part of the digestive system Small Intestine Liver and Pancreas aid the sm. Intestine by adding enzymes to help break down food Liver and Pancreas aid the sm. Intestine by adding enzymes to help break down food The nutrients are broken down small enough to pass through the lining of the small intestine, and into the blood (diffusion). The nutrients are broken down small enough to pass through the lining of the small intestine, and into the blood (diffusion). Nutrients are carried away to the liver and other body parts to be processed, stored and distributed. Nutrients are carried away to the liver and other body parts to be processed, stored and distributed.

13. Identify and tell the function of each part of the digestive system Large Intestine Useful substances that were not absorbed in the small intestine, such as spare water and body minerals, are absorbed through the walls of the large intestine, back into the blood. Useful substances that were not absorbed in the small intestine, such as spare water and body minerals, are absorbed through the walls of the large intestine, back into the blood.

14. Identify and tell the function of each part of the digestive system Large Intestine The remains are formed into brown, semi-solid feces, ready to be removed from the body The remains are formed into brown, semi-solid feces, ready to be removed from the body

15. Identify and tell the function of each part of the digestive system Rectum Store the feces. Store the feces.Anus ring of muscle that squeezes the feces out of the body. ring of muscle that squeezes the feces out of the body.

16. Accessory Organs Pancreas The pancreas, like the stomach, makes digestive juices called enzymes which help to digest food further as it enters the small intestines. The pancreas, like the stomach, makes digestive juices called enzymes which help to digest food further as it enters the small intestines.

17. Identify and tell the function of each part of the digestive system Gall Bladder A small baglike part under the liver. A small baglike part under the liver. It stores a fluid called bile, which is made in the liver. It stores a fluid called bile, which is made in the liver.

18. Identify and tell the function of each part of the digestive system Gall Bladder As food from a meal enters the small intestine, bile flows from the gall bladder along the bile duct into the intestine. As food from a meal enters the small intestine, bile flows from the gall bladder along the bile duct into the intestine. It helps to digest fatty foods and also contains wastes for removal. It helps to digest fatty foods and also contains wastes for removal.

19. Identify and tell the function of each part of the digestive system Liver Blood from the intestines enters to the liver, carrying nutrients, vitamins and minerals, and other products from digestion. Blood from the intestines enters to the liver, carrying nutrients, vitamins and minerals, and other products from digestion.

20. Identify and tell the function of each part of the digestive system Liver The liver is like a food- processing factory with more than 200 different jobs. The liver is like a food- processing factory with more than 200 different jobs. –It stores some nutrients –changes them from one form to another –releases them into the blood

21. To quiz yourself over the parts of the digestive system, click here: http://www.tvdsb.on.ca/westmin/ science/sbi3a1/digest/digdiag.htm http://www.tvdsb.on.ca/westmin/ science/sbi3a1/digest/digdiag.htm

22. Describe water Most of the nutrients in your body can't be used unless they are carried in a solution. This means that they have to be dissolved in water. Most of the nutrients in your body can't be used unless they are carried in a solution. This means that they have to be dissolved in water. In cells, chemical reactions take place in solutions. In cells, chemical reactions take place in solutions.

23. Describe water Most of the material absorbed from the cavity of the small intestine is water in which salt is dissolved. Most of the material absorbed from the cavity of the small intestine is water in which salt is dissolved. The salt and water come from the food and liquid we swallow and the juices secreted by the many digestive glands. The salt and water come from the food and liquid we swallow and the juices secreted by the many digestive glands.

24. For more information about the digestive system, click here: http://kidshealth.org/kid/body/dig est_noSW.html http://kidshealth.org/kid/body/dig est_noSW.html