1. © 2013 Pearson Education, Inc. Lectures by Edward J. Zalisko PowerPoint ® Lectures for Campbell Essential Biology, Fifth Edition, and Campbell Essential Biology with Physiology, Fourth Edition – Eric J. Simon, Jean L. Dickey, and Jane B. Reece Chapter 25 Hormones

2. Biology and Society: Sluggers and Steroids The 1998 major league home run records reflect another chapter in baseball’s shameful “steroids era.” The abuse of anabolic steroids by athletes increases muscle mass and brings greater power to a batter’s swing. © 2013 Pearson Education, Inc.

3. Figure 25.0

4. HORMONES: AN OVERVIEW Hormones are produced by most plants and animals. Animal hormones –are made and secreted mainly by endocrine glands, –are usually carried by the circulatory system, and –communicate regulatory messages to specific sites in the body. © 2013 Pearson Education, Inc.

5. The endocrine system –consists of all hormone-secreting cells and –is the body’s main system for internal chemical regulation. HORMONES: AN OVERVIEW © 2013 Pearson Education, Inc.

6. Endocrine cells secrete into the bloodstream hormones that –can affect many cells in many different body organs but –only affect target cells, cells that have receptors for that specific hormone. HORMONES: AN OVERVIEW © 2013 Pearson Education, Inc.

7. Figure 25.1 Endocrine cell Blood vessel Membrane- enclosed sacs Hormone molecules Receptor protein Target cell Adrenal glands (type of endocrine gland), which sit atop the kidneys

8. There are two general mechanisms by which hormones trigger changes in target cells: 1.Water-soluble hormones trigger responses without ever entering their target cells. HORMONES: AN OVERVIEW © 2013 Pearson Education, Inc.

9. Figure 25.2-3 Water- soluble hormone Receptor protein Target cell Plasma membrane Relay molecules Signal transduction pathway Cytoplasmic response or Gene regulation Nucleus 123

10. 2.Lipid-soluble hormones trigger responses after entering the target cell. HORMONES: AN OVERVIEW © 2013 Pearson Education, Inc.

11. Figure 25.3-4 Lipid- soluble hormone Receptor protein Target cell Plasma membrane Hormone- receptor complex Gene regulation Nucleus 2134

12. THE HUMAN ENDOCRINE SYSTEM The human endocrine system consists of about a dozen major glands that may have –only endocrine functions or –endocrine and non-endocrine functions. The major endocrine glands in humans are spread about the human body. © 2013 Pearson Education, Inc.

13. Figure 25.4 Thyroid gland Pituitary gland Hypothalamus Parathyroid glands (embedded within thyroid) Adrenal glands (atop kidneys) Testes (male) Pancreas Ovaries (female)

14. Hormones have a wide range of –target cells and –effects. THE HUMAN ENDOCRINE SYSTEM © 2013 Pearson Education, Inc.

15. Table 25.1

16. The Hypothalamus and Pituitary Gland The hypothalamus –is part of the brain, –is the main control center of the endocrine system, and –receives information from nerves about –the internal condition of the body and –the external environment. © 2013 Pearson Education, Inc.

17. The pituitary gland –is a pea-sized structure that hangs below the hypothalamus, –responds to signals from the hypothalamus, and –secretes hormones that influence numerous body functions. The Hypothalamus and Pituitary Gland © 2013 Pearson Education, Inc.

18. Figure 25.5 Hypothalamus Posterior pituitary Brain Bone Anterior pituitary

19. The pituitary gland consists of two parts: 1.The posterior pituitary –is an extension of the hypothalamus, –stores hormones, and –secretes hormones made in the hypothalamus. The Hypothalamus and Pituitary Gland © 2013 Pearson Education, Inc.

20. 2. The anterior pituitary –synthesizes its own hormones, such as FSH and LH, and –secretes hormones directly into the blood. The Hypothalamus and Pituitary Gland © 2013 Pearson Education, Inc.

21. The hypothalamus operates through the posterior pituitary to direct the activities of the kidneys. –The hypothalamus makes antidiuretic hormone (ADH), which is stored and released by the posterior pituitary. –ADH helps kidney cells reabsorb water, preventing dehydration by decreasing urine volume. The Hypothalamus and Pituitary Gland © 2013 Pearson Education, Inc.

22. Figure 25.6 Hypothalamus Kidneys Anterior pituitary ADH Posterior pituitary Blood vessel (ADH increases water reabsorption and prevents dehydration)

23. The anterior lobe of the pituitary also secretes human growth hormone (HGH), which –promotes development and enlargement of all parts of the body and –can lead to –dwarfism, if too little GH is produced, or –gigantism, if too much GH is produced. The Hypothalamus and Pituitary Gland © 2013 Pearson Education, Inc.

24. Figure 25.7 (a) Overproduction of HGH during adulthood (b) Overproduction of HGH during development (c) Underproduction of HGH during development

25. Endorphins –are produced by the anterior pituitary and –act as natural painkillers. The Hypothalamus and Pituitary Gland © 2013 Pearson Education, Inc.

26. The Thyroid and Parathyroid Glands The thyroid gland –is located in the neck just under the larynx and –produces the hormones thyroxine and triiodothyronine, which increase –oxygen consumption and –metabolic rate in all the cells of your body. © 2013 Pearson Education, Inc.

27. Hypothyroidism –results from too little thyroid hormone in the blood and –can result from –dietary deficiencies of iodine or –a defective thyroid gland. The Thyroid and Parathyroid Glands © 2013 Pearson Education, Inc.

28. Hyperthyroidism (Graves disease) –results from too much thyroid hormone in the blood and –can lead to –overheating, –profuse sweating, –high blood pressure, and –protruding eyeballs. The Thyroid and Parathyroid Glands © 2013 Pearson Education, Inc.

29. The parathyroid glands –are four disk-shaped glands embedded within the thyroid and –produce parathyroid hormone, which raises calcium levels in the blood. Calcitonin –is produced by the thyroid gland and –lowers calcium levels in the blood. The Thyroid and Parathyroid Glands © 2013 Pearson Education, Inc.

30. Calcitonin and parathyroid hormone are antagonistic hormones, because they have opposite effects on calcium levels in the blood. The Thyroid and Parathyroid Glands © 2013 Pearson Education, Inc.

31. Figure 25.8 Thyroid gland releases calcitonin Homeostasis: Normal blood calcium level Calcitonin Stimulus: Rising blood Ca 2 + Ca 2 + level Stimulates Ca 2 + deposition Reduces Ca 2 + uptake Ca 2 + level in blood falls Stimulus: Falling blood Ca 2 + Ca 2 + level in blood rises Release of parathyroid hormone (PTH) Parathyroid gland PTH Stimulates Ca 2 + release Increases Ca 2 + uptake Increases Ca 2 + uptake 123456

32. The Pancreas The pancreas produces two antagonistic hormones that play important roles in managing the body’s energy supplies: 1. insulin, which reduces blood sugar levels and 2. glucagon, which increases blood sugar levels. © 2013 Pearson Education, Inc.

33. Figure 25.9 Pancreas releases insulin Stimulus: Rising blood glucose Glucose level Homeostasis: Normal blood glucose level Insulin 321654 Body cells take up glucose Liver stores glucose as glycogen Blood glucose level falls Stimulus: Declining blood glucose Glucose level Glucagon Pancreas releases glucagon Liver breaks down glycogen Blood glucose level rises

34. Diabetes mellitus is a serious hormonal disease in which body cells are unable to absorb glucose from the blood because either –there is not enough insulin produced (type 1, or insulin-dependent diabetes) or –the target cells do not respond normally to insulin (type 2, or non-insulin-dependent diabetes). The Pancreas © 2013 Pearson Education, Inc.

35. Diabetes affects about 8% of all Americans. More than 90% of those affected have type 2 diabetes, which is associated with being –overweight and –underactive. People with diabetes use glucose meters to measure the amount of glucose in the blood. The Pancreas © 2013 Pearson Education, Inc.

36. Figure 25.10

37. The Adrenal Glands The adrenal glands are paired structures resting atop each kidney. Each adrenal gland consists of two glands: 1.the central adrenal medulla and 2.the outer adrenal cortex. © 2013 Pearson Education, Inc.

38. The adrenal medulla secretes epinephrine and norepinephrine, hormones that –enable a rapid, short-term response to stress and –produce the “fight-or-flight” response. The Adrenal Glands © 2013 Pearson Education, Inc.

39. Stressful stimuli activate nerve cells in the hypothalamus that send signals to stimulate the adrenal medulla to secrete –epinephrine and –norepinephrine. The Adrenal Glands © 2013 Pearson Education, Inc.

40. The adrenal cortex –is also stimulated by the hypothalamus and –secretes corticosteroid hormones (including glucocorticoids) that provide a slower, longer- lasting response to stress. The Adrenal Glands © 2013 Pearson Education, Inc.

41. Figure 25.11 Adrenal gland Adrenal medulla Adrenal cortex Kidney Adrenal cortex Nerve signals Nerve cell Nerve cell Spinal cord (cross section) Adrenal medulla Epinephrine and norepinephrine Corticosteroids ACTH Anterior pituitary Releasing hormone Blood vessel Hypothalamus STRESS Long-term stress response Short-term stress response ACTH Proteins and fats broken down and converted to glucose, leading to increased blood glucose Immune system may be suppressed Glycogen broken down to glucose; increased blood glucose Increased blood pressure, breathing rate, heart rate, and metabolic rate Change in blood flow patterns, leading to increased alertness and decreased digestive activity 31245

42. The Gonads The gonads secrete sex hormones that –affect growth and development and –regulate –reproductive cycles and –sexual behavior. © 2013 Pearson Education, Inc.

43. Males and females have the same three types of sex hormones: 1.estrogens, 2.progestins, and 3.androgens. The Gonads © 2013 Pearson Education, Inc.

44. Estrogens –maintain the female reproductive system and –promote the development of specific female features, such as breasts and wider hips. Progestins, such as progesterone, are primarily involved in preparing the uterus to support a developing embryo. The Gonads © 2013 Pearson Education, Inc.

45. Androgens, mainly testosterone, stimulate the development and maintenance of the male reproductive system. The Gonads © 2013 Pearson Education, Inc.

46. Evolution Connection: Steroids and Male Aggression Testosterone and other androgens –promote the development and maintenance of the human male reproductive system and –play a similar role in all vertebrates.

47. In addition to determining the male sexual condition, in many vertebrates, androgens –are responsible for male vocalizations and –promote aggressive behavior. Evolution Connection: Steroids and Male Aggression © 2013 Pearson Education, Inc.

48. Figure 25.13

49. The different roles for androgens among vertebrates illustrate two central aspects of life resulting from Darwinian evolution: 1.the unity of life (a consistent effect on the development of the male gonads) and 2.the diversity of life (the variety of secondary effects). Evolution Connection: Steroids and Male Aggression © 2013 Pearson Education, Inc.

50. Figure 25.UN01

51. Figure 25.UN02

52. Figure 25.UN03

53. Figure 25.UN04

54. Figure 25.UN05

55. Figure 25.UN06

56. Figure 25.UN07 Water- soluble hormone Receptor protein Cytoplasmic response Nucleus or Gene regulation Signal transduction pathway Lipid- soluble hormone Receptor protein Nucleus Gene regulation Hormone- receptor complex

57. Figure 25.UN08 Blood vessels Brain Posterior pituitary: Stores and secretes hormones made by hypothalamus Hypothalamus: Master control center of the endocrine system Anterior pituitary: Controlled by hypothalamus; produces and secretes its own hormones

58. Figure 25.UN09 causes release releases Thyroid Parathyroids Calcitonin Parathyroid hormone Ca 2  in blood

59. Figure 25.UN10 releases causes Pancreas causes Glucose in blood Glucagon Insulin Glucose in blood releases