Section 1: The Digestive System

2. Chapter 35 Digestive and Endocrine Systems Section 1: The Digestive System Section2: Nutrition Section 3: The Endocrine System

3. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Functions of the Digestive System • Ingests food • Breaks it down so nutrients can be absorbed • Eliminates what cannot be digested

4. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Ingestion • Mechanical digestion • Involves chewing food to break it down into smaller pieces • Chemical digestion • The action of enzymes in breaking down large molecules into smaller molecules

5. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System

6. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Esophagus • Muscular tube that connects the pharynx, or throat, to the stomach Peristalsis • Smooth muscles contract rhythmically to move food through the digestive system.

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8. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Stomach • Walls of the stomach are composed of three overlapping layers of smooth muscle that are involved with mechanical digestion. • Environment inside the stomach is very acidic. • Pepsin is an enzyme involved in the process of the chemical digestion of proteins.

9. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Small Intestine • Smooth muscles in the wall of the small intestine continue the process of mechanical digestion and push the food farther through the digestive tract by peristalsis.

10. The completion of chemical digestion in the small intestine depends on Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System • Pancreas • Liver • Gallbladder

11. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Pancreas • Produces enzymes that digest carbohydrates, proteins, and fats • Produces hormones

12. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Liver • Produces bile, which helps to break down fats Gallbladder • Stores excess bile

13. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System • Food nutrients are absorbed from the small intestine into the bloodstream through fingerlike structures called villi. • Villi increase the surface area of the small intestine.

14. Digestive and Endocrine Systems Chapter 35 35.1 The Digestive System Large Intestine • A primary function of the colon is to absorb water from the chyme. • Peristalsis moves feces toward the rectum.

15. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition Calories • Nutrition is the process by which a person takes in and uses food. • ACalorie is a unit used to measure the energy content of foods. • The energy content of food can be measured by burning the food and converting the stored energy to heat.

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17. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition

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19. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition Carbohydrates • Complex carbohydrates are macromolecules such as starches, which are long chains of sugar. • Complex carbohydrates are broken down into simple sugars.

20. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition • Simple sugars are absorbed through villi. • Glucose is stored in the liver. • Dietary fiber helps keep food moving through the digestive tract.

21. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition Fats • Fats are the most concentrated energy source available to the body. • Building blocks for the body • Classified as saturated and unsaturated • Meats and cheeses are sources of saturated fats. • Plants are the main source of unsaturated fats.

22. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition • Fats are digested in the small intestine and broken down into fatty acids and glycerol. • Fatty acids can be absorbed through the villi and circulated in the blood throughout the body.

23. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition Proteins • Proteins are broken down to their subunit amino acids. • Amino acids are absorbed into the bloodstream and carried to various body cells. • Essential amino acids are the eight amino acids that must be included in a person’s diet.

24. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition Food Pyramid

25. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition Vitamins and Minerals • Vitamins are organic compounds that are needed in small amounts for metabolic activities. • Minerals are inorganic compounds used by the body as building material, and they are involved with metabolic functions.

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30. Digestive and Endocrine Systems Chapter 35 35.2 Nutrition Nutrition Labels • Based on a 2000-Calorie per day diet • name of the food • net weight or volume • name and address of manufacturer, distributor, or packager • ingredients The Digestive and Endocrine Systems • nutrient content

31. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Action of Hormones • Endocrine glandsproduce hormones, which are released into the bloodstream and distributed to body cells. • Hormones are classified as steroid hormones and nonsteroid or amino acid hormones.

32. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Steroid Hormones • Soluble in lipids and therefore can diffuse through the plasma membrane of a target cell • Bind to a receptor in the cell • The hormone and the receptor that are bound together bind to DNA in the nucleus.

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34. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Amino Acid Hormones • Nonsteroid hormones are composed of amino acids. • Bind to receptors found on the plasma membrane of a target cell because they cannot diffuse through the plasma membrane

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36. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Negative Feedback • Negative feedback returns a system to a set point once it deviates sufficiently from that set point.

37. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Endocrine Glands and Their Hormones • Pituitary gland • Situated at the base of the brain • Secretes hormones that regulate many body functions • Regulates other endocrine glands

38. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Thyroid and Parathyroid Glands • Thyroxinecauses cells of the body to have a higher rate of metabolism. • Calcitonin is a hormone that is partly responsible for the regulation of calcium. • Parathyroidhormone increases blood calcium levels.

39. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Pancreas • Crucial role in the production of enzymes that digest carbohydrates, proteins, and fats • Secretes the hormones insulin and glucagon which work together to maintain homeostasis

40. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Adrenal Glands • Located just above the kidneys • Manufactures the steroid hormone aldosterone and a group of hormones called glucocorticoids

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42. Digestive and Endocrine Systems Chapter 35 35.3 The Endocrine System Link to the Nervous System • The hypothalamus produces two hormones, oxytocin and antidiuretic hormone. • The antidiuretichormone (ADH) functions in homeostasis by regulating water balance.

43. Digestive and Endocrine Systems Chapter 35 Chapter Resource Menu Chapter Diagnostic Questions Formative Test Questions Chapter Assessment Questions Standardized Test Practice biologygmh.com Glencoe Biology Transparencies Image Bank Vocabulary Animation Click on a hyperlink to view the corresponding feature.

44. A B C D Digestive and Endocrine Systems Chapter 35 CDQ 1 Chapter Diagnostic Questions Which is an enzyme responsible for breaking down starches into sugars? amylase appendix peristalsis pepsin

45. A B C D Digestive and Endocrine Systems Chapter 35 CDQ 2 Chapter Diagnostic Questions Cellulose is an example of what type of food? fat protein carbohydrate vegetable

46. A B C D Digestive and Endocrine Systems Chapter 35 CDQ 3 Chapter Diagnostic Questions Which glands play a role in the “fight or flight” response? adrenal pituitary parathyroid thyroid

47. A B Digestive and Endocrine Systems Chapter 35 FQ 1 35.1 Formative Questions What type of digestion is carried out by the action of smooth muscles in the stomach and small intestine? chemical digestion mechanical digestion

48. A B C D Digestive and Endocrine Systems Chapter 35 FQ 2 35.1 Formative Questions Where does the chemical digestion of starches begin? mouth stomach small intestine large intestine

49. A B C D Digestive and Endocrine Systems Chapter 35 FQ 3 35.1 Formative Questions In what type of solution is the enzyme pepsin most active? acidic solution buffered solution gaseous solution concentrated sugar solution

50. A B C D Digestive and Endocrine Systems Chapter 35 FQ 4 35.1 Formative Questions What is the primary function of the large intestine? absorption of water from chyme chemical breakdown of feces excretion of acids and hormones mechanical digestion of lipids