2. (c) McGraw Hill Ryerson 2007 2.2 The Digestive and Excretory Systems Nutrients are substances the body requires for energy, growth, development, repair, or maintenance. We get nutrients from what we eat and drink. See pages 64 - 65 Four Food Groups Grain products Vegetables and fruit Milk products Meat and alternatives

4. (c) McGraw Hill Ryerson 2007 Types of Nutrients Carbohydrates  The bodies quickest source of energy  Examples include: rice, vegetables, cereal, and bread Proteins  Used to build parts of your bodies muscles, skin, hair, and nails  Examples include: fish, meat, eggs, nuts, soy products See pages 66 - 69

5. (c) McGraw Hill Ryerson 2007 Types of Nutrients Fats  Used to build cell membranes and can be stored for future energy.  Examples include: butter, vegetable oil, and meat Minerals and Vitamins  Needed in small amounts to perform various body functions  Two common minerals and vitamins are calcium and vitamin D See pages 66 - 69 Water is not a nutrient but is necessary for life!

6. Types of Nutrients (c) McGraw Hill Ryerson 2007

7. The Four Stages of Digestion See page 70 The process in which food is broken down, nutrients are absorbed, and wastes eliminated is called digestion and occurs in the digestive system. The fours stages of digestion are:  Ingesting  Digesting  Absorbing  Eliminating

8. (c) McGraw Hill Ryerson 2007

9. Stage 1: Ingesting See page 71 Ingesting, or ingestion, means to bring food into the body. This is the starting point of the digestive process.

10. (c) McGraw Hill Ryerson 2007 Stage 2: Digesting See page 71 Mechanical digestion occurs when your teeth and tongue break food into small enough pieces to swallow. Each small piece of food is called bolus. Chemical digestion occurs when saliva begins to break down the bolus. An enzyme in your saliva begins to break down simple and complex carbohydrates. The Mouth

12. (c) McGraw Hill Ryerson 2007 Stage 2: Digesting See page 72 When you swallow, your food enters the esophagus. The esophagus is a long muscular tube that carries food to your stomach. The bolus is pushed through the esophagus in a process called peristalsis. The Esophagus

17. (c) McGraw Hill Ryerson 2007 Stage 2: Digesting See page 73 Inside the stomach is gastric juice, which is very acidic. The stomach walls are lined with mucus to protect the tissue from being damaged by the acid. An enzyme called pepsin, present in gastric juice, breaks down protein. The bolus that enters your stomach breaks down into a liquid called chyme. The Stomach

22. (c) McGraw Hill Ryerson 2007 Stage 2: Digesting See page 74 The first metre of the small intestine is called the duodenum. The pancreas adds enzymes that help break down the carbohydrates, protein, and fat in the chyme. The liver produces bile which is stored in the gall bladder. Bile breaks the globs of fat into smaller droplets. The Small Intestine

23. (c) McGraw Hill Ryerson 2007

28. Stage 3: Absorbing See page 75 Absorption is the process in which nutrients and water are absorbed by the small and large intestine. The small intestine is covered with villi to help increase the rate at which nutrients are absorbed. The large intestine absorbs water and some minerals. The Small and Large Intestine

34. (c) McGraw Hill Ryerson 2007 Stage 4: Eliminating See page 76 Any solid material, undigested by the end of the large intestine is called feces. Feces are stored in the rectum until they are eliminated through the anus. Liquid and gas wastes are removed by your excretory system.  The main organs in your excretory system are your kidneys and your bladder.

35. (c) McGraw Hill Ryerson 2007

37. Kidney : filters the blood and removes waste KIDNEY

38. Ureter : Moves the urine to the bladder via peristalsis KIDNEY URETER

39. Bladder : stores the urine KIDNEY URETER BLADDER

40. Urethra : when the sphincter relaxes, the urethra carries the urine outside the body. 20 cm in males 4 cm in females KIDNEY URETER BLADDER URETHRA

42. (c) McGraw Hill Ryerson 2007 Eating Disorders Anorexia nervosa is a disorder when a person severely restricts what they eat. Bulimia nervosa is a disorder when a person eats large amounts of food and then vomits or takes laxatives to get rid of the food before it is completely digested. See page 77

43. (c) McGraw Hill Ryerson 2007 Take the Section 2.2 Quiz