2.  Found at the base of the throat  Consists of two lobes and a connecting isthmus  Produces two hormones › Thyroid hormone › Calcitonin

3. Figure 9.7a

4.  Thyroid hormone › Major metabolic hormone › Composed of two active iodine-containing hormones  Thyroxine (T 4 )—secreted by thyroid follicles  Triiodothyronine (T 3 )—conversion of T 4 at target tissues

5. Figure 9.7b

6.  Thyroid hormone disorders › Goiters  Thyroid gland enlarges due to lack of iodine  Salt is iodized to prevent goiters › Cretinism  Caused by hyposecretion of thyroxine  Results in dwarfism during childhood

7. Figure 9.8

8.  Thyroid hormone disorders (continued) › Myxedema  Caused by hypothyroidism in adults  Results in physical and mental slugishness › Graves’ disease  Caused by hyperthyroidism  Results in increased metabolism, heat intolerance, rapid heartbeat, weight loss, and exophthalmos

9. Figure 9.9

10.  Calcitonin › Decreases blood calcium levels by causing its deposition on bone › Antagonistic to parathyroid hormone › Produced by parafollicular cells › Parafollicular cells are found between the follicles

11. Figure 9.7b

12.  Tiny masses on the posterior of the thyroid  Secrete parathyroid hormone (PTH) › Stimulate osteoclasts to remove calcium from bone › Stimulate the kidneys and intestine to absorb more calcium › Raise calcium levels in the blood

13. Figure 9.10 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Thyroid gland releases calcitonin Osteoclasts degrade bone matrix and release Ca 2+ into blood PTH Calcitonin Calcitonin stimulates calcium salt deposit in bone Parathyroid glands release parathyroid hormone (PTH) Thyroid gland Parathyroid glands Falling blood Ca 2+ levels Imbalance

14. Figure 9.10, step 1 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Imbalance

15. Figure 9.10, step 2 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Thyroid gland Imbalance

16. Figure 9.10, step 3 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Thyroid gland releases calcitonin Calcitonin Thyroid gland Imbalance

17. Figure 9.10, step 4 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Thyroid gland releases calcitonin Calcitonin Calcitonin stimulates calcium salt deposit in bone Thyroid gland Imbalance

18. Figure 9.10, step 5 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Thyroid gland releases calcitonin Calcitonin Calcitonin stimulates calcium salt deposit in bone Thyroid gland

19. Figure 9.10, step 6 Calcium homeostasis of blood 9–11 mg/100 ml Falling blood Ca 2+ levels Imbalance

20. Figure 9.10, step 7 Calcium homeostasis of blood 9–11 mg/100 ml Thyroid gland Parathyroid glands Falling blood Ca 2+ levels Imbalance

21. Figure 9.10, step 8 Calcium homeostasis of blood 9–11 mg/100 ml PTH Parathyroid glands release parathyroid hormone (PTH) Thyroid gland Parathyroid glands Falling blood Ca 2+ levels Imbalance

22. Figure 9.10, step 9 Calcium homeostasis of blood 9–11 mg/100 ml Osteoclasts degrade bone matrix and release Ca 2+ into blood PTH Parathyroid glands release parathyroid hormone (PTH) Thyroid gland Parathyroid glands Falling blood Ca 2+ levels Imbalance

23. Figure 9.10, step 10 Calcium homeostasis of blood 9–11 mg/100 ml Osteoclasts degrade bone matrix and release Ca 2+ into blood PTH Parathyroid glands release parathyroid hormone (PTH) Thyroid gland Parathyroid glands

24. Figure 9.10, step 11 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Thyroid gland releases calcitonin Osteoclasts degrade bone matrix and release Ca 2+ into blood PTH Calcitonin Calcitonin stimulates calcium salt deposit in bone Parathyroid glands release parathyroid hormone (PTH) Thyroid gland Parathyroid glands Falling blood Ca 2+ levels Imbalance

25.  Sit on top of the kidneys  Two regions › Adrenal cortex—outer glandular region has three layers  Mineralocorticoids secreting area  Glucocorticoids secreting area  Sex hormones secreting area › Adrenal medulla—inner neural tissue region

26. Figure 9.11

27.  Mineralocorticoids (mainly aldosterone) › Produced in outer adrenal cortex › Regulate mineral content in blood › Regulate water and electrolyte balance › Target organ is the kidney › Production stimulated by renin and aldosterone › Production inhibited by atrial natriuretic peptide (ANP)

28. Figure 9.12

29.  Glucocorticoids (including cortisone and cortisol) › Produced in the middle layer of the adrenal cortex › Promote normal cell metabolism › Help resist long-term stressors › Released in response to increased blood levels of ACTH

30. Figure 9.13 Short termMore prolonged Stress Hypothalamus Nerve impulses Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH MineralocorticoidsGlucocorticoids 1.Retention of sodium and water by kidneys 2.Increased blood volume and blood pressure 1. Proteins and fats converted to glucose or broken down for energy 2. Increased blood sugar 3. Suppression of immune system Long-term stress response Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine) 1. Increased heart rate 2. Increased blood pressure 3. Liver converts glycogen to glucose and releases glucose to blood 4. Dilation of bronchioles 5. Changes in blood flow patterns, leading to increased alertness and decreased digestive and kidney activity 6. Increased metabolic rate

31. Figure 9.13, step 1 Short term Stress Hypothalamus

32. Figure 9.13, step 2 Short term Stress Hypothalamus Nerve impulses Spinal cord

33. Figure 9.13, step 3 Short term Stress Hypothalamus Nerve impulses Spinal cord Adrenal medulla Preganglionic sympathetic fibers

34. Figure 9.13, step 4 Short term Stress Hypothalamus Nerve impulses Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine)

35. Figure 9.13, step 5 Short term Stress Hypothalamus Nerve impulses Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine) 1. Increased heart rate 2. Increased blood pressure 3. Liver converts glycogen to glucose and releases glucose to blood 4. Dilation of bronchioles 5. Changes in blood flow patterns, leading to increased alertness and decreased digestive and kidney activity 6. Increased metabolic rate

36. Figure 9.13, step 6 More prolonged Stress Hypothalamus

37. Figure 9.13, step 7 More prolonged Stress Hypothalamus Releasing hormone Corticotropic cells of anterior pituitary

38. Figure 9.13, step 8 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH

39. Figure 9.13, step 9 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH Mineralocorticoids Long-term stress response

40. Figure 9.13, step 10 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH MineralocorticoidsGlucocorticoids Long-term stress response

41. Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 11 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH MineralocorticoidsGlucocorticoids 1.Retention of sodium and water by kidneys 2.Increased blood volume and blood pressure Long-term stress response

42. Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 12 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH MineralocorticoidsGlucocorticoids 1.Retention of sodium and water by kidneys 2.Increased blood volume and blood pressure 1. Proteins and fats converted to glucose or broken down for energy 2. Increased blood sugar 3. Suppression of immune system Long-term stress response

43. Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 13 Short termMore prolonged Stress Hypothalamus Nerve impulses Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH Mineralocorticoids Glucocorticoids 1.Retention of sodium and water by kidneys 2.Increased blood volume and blood pressure 1. Proteins and fats converted to glucose or broken down for energy 2. Increased blood sugar 3. Suppression of immune system Long-term stress response Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine) 1. Increased heart rate 2. Increased blood pressure 3. Liver converts glycogen to glucose and releases glucose to blood 4. Dilation of bronchioles 5. Changes in blood flow patterns, leading to increased alertness and decreased digestive and kidney activity 6. Increased metabolic rate

44.  Sex hormones › Produced in the inner layer of the adrenal cortex › Small amounts are made throughout life › Mostly androgens (male sex hormones) are made but some estrogens (female sex hormones) are also formed

45.  Adrenal cortex disorders › Addison’s disease  Results from hyposecretion of all adrenal cortex hormones  Bronze skin tone, muscles are weak, burnout, susceptibility to infection › Hyperaldosteronism  May result from an ACTH-releasing tumor  Excess water and sodium are retained leading to high blood pressure and edema

46.  Adrenal cortex disorders › Cushing’s syndrome  Results from a tumor in the middle cortical area of the adrenal cortex  “Moon face,” “buffalo hump” on the upper back, high blood pressure, hyperglycemia, weakening of bones, depression › Masculinization  Results from hypersecretion of sex hormones  Beard and male distribution of hair growth

47.  Produces two similar hormones (catecholamines) › Epinephrine (adrenaline) › Norepinephrine (noradrenaline)  These hormones prepare the body to deal with short-term stress (“fight or flight”) by › Increasing heart rate, blood pressure, blood glucose levels › Dilating small passageways of lungs

48. Figure 9.11

49.  The pancreas is a mixed gland and has both endocrine and exocrine functions  The pancreatic islets produce hormones › Insulin—allows glucose to cross plasma membranes into cells from beta cells › Glucagon—allows glucose to enter the blood from alpha cells › These hormones are antagonists that maintain blood sugar homeostasis

50. Figure 9.14a–b

51. Figure 9.14b–c

52. Figure 9.15 Insulin-secreting cells of the pancreas activated; release insulin into the blood Elevated blood sugar levels Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Rising blood glucose levels return blood sugar to homeostatic set point; stimulus for glucagon release diminishes Blood glucose levels decline to set point; stimulus for insulin release diminishes Stimulus: declining blood glucose levels (e.g., after skipping a meal) Low blood sugar levels Glucagon-releasing cells of pancreas activated; release glucagon into blood; target is the liver Uptake of glucose from blood is en- hanced in most body cells Liver breaks down glycogen stores and releases glucose to the blood Liver takes up glucose and stores it as glycogen Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance

53. Figure 9.15, step 1 Homeostasis: Normal blood glucose levels (90 mg/100ml)

54. Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance Figure 9.15, step 2

55. Elevated blood sugar levels Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance Figure 9.15, step 3

56. Insulin-secreting cells of the pancreas activated; release insulin into the blood Elevated blood sugar levels Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance Figure 9.15, step 4

57. Insulin-secreting cells of the pancreas activated; release insulin into the blood Elevated blood sugar levels Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Uptake of glucose from blood is en- hanced in most body cells Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance Figure 9.15, step 5

58. Insulin-secreting cells of the pancreas activated; release insulin into the blood Elevated blood sugar levels Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Uptake of glucose from blood is en- hanced in most body cells Liver takes up glucose and stores it as glycogen Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance Figure 9.15, step 6

59. Figure 9.15, step 7 Insulin-secreting cells of the pancreas activated; release insulin into the blood Elevated blood sugar levels Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Blood glucose levels decline to set point; stimulus for insulin release diminishes Uptake of glucose from blood is en- hanced in most body cells Liver takes up glucose and stores it as glycogen Homeostasis: Normal blood glucose levels (90 mg/100ml)

60. Figure 9.15, step 8 Stimulus: declining blood glucose levels (e.g., after skipping a meal) Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance

61. Figure 9.15, step 9 Stimulus: declining blood glucose levels (e.g., after skipping a meal) Low blood sugar levels Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance

62. Figure 9.15, step 10 Stimulus: declining blood glucose levels (e.g., after skipping a meal) Low blood sugar levels Glucagon-releasing cells of pancreas activated; release glucagon into blood; target is the liver Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance

63. Figure 9.15, step 11 Stimulus: declining blood glucose levels (e.g., after skipping a meal) Low blood sugar levels Glucagon-releasing cells of pancreas activated; release glucagon into blood; target is the liver Liver breaks down glycogen stores and releases glucose to the blood Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance

64. Figure 9.15, step 12 Rising blood glucose levels return blood sugar to homeostatic set point; stimulus for glucagon release diminishes Stimulus: declining blood glucose levels (e.g., after skipping a meal) Low blood sugar levels Glucagon-releasing cells of pancreas activated; release glucagon into blood; target is the liver Liver breaks down glycogen stores and releases glucose to the blood Homeostasis: Normal blood glucose levels (90 mg/100ml)

65. Figure 9.15, step 13 Insulin-secreting cells of the pancreas activated; release insulin into the blood Elevated blood sugar levels Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Rising blood glucose levels return blood sugar to homeostatic set point; stimulus for glucagon release diminishes Blood glucose levels decline to set point; stimulus for insulin release diminishes Stimulus: declining blood glucose levels (e.g., after skipping a meal) Low blood sugar levels Glucagon-releasing cells of pancreas activated; release glucagon into blood; target is the liver Uptake of glucose from blood is en- hanced in most body cells Liver breaks down glycogen stores and releases glucose to the blood Liver takes up glucose and stores it as glycogen Homeostasis: Normal blood glucose levels (90 mg/100ml) Imbalance

66.  Found on the third ventricle of the brain  Secretes melatonin › Helps establish the body’s wake and sleep cycles › Believed to coordinate the hormones of fertility in humans

67. Figure 9.3

68.  Located posterior to the sternum  Largest in infants and children  Produces thymosin › Matures some types of white blood cells › Important in developing the immune system

69.  Ovaries › Produce eggs › Produce two groups of steroid hormone  Estrogens  Progesterone  Testes › Produce sperm › Produce androgens, such as testosterone

70. Figure 9.3

71.  Estrogens › Stimulate the development of secondary female characteristics › Mature female reproductive organs  With progesterone, estrogens also › Promote breast development › Regulate menstrual cycle

72.  Progesterone › Acts with estrogen to bring about the menstrual cycle › Helps in the implantation of an embryo in the uterus › Helps prepare breasts for lactation

73.  Produce several androgens  Testosterone is the most important androgen › Responsible for adult male secondary sex characteristics › Promotes growth and maturation of male reproductive system › Required for sperm cell production Male Hormones PLAY

74.  Parts of the small intestine  Parts of the stomach  Kidneys  Heart  Many other areas have scattered endocrine cells

75. Table 9.2 (1 of 2)

76. Table 9.2 (2 of 2)

77.  Produces hormones that maintain the pregnancy  Some hormones play a part in the delivery of the baby  Produces human chorionic gonadotropin (hCG) in addition to estrogen, progesterone, and other hormones

78.  Most endocrine organs operate smoothly until old age › Menopause is brought about by lack of efficiency of the ovaries › Problems associated with reduced estrogen are common › Growth hormone production declines with age › Many endocrine glands decrease output with age