1. PowerPoint ® Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings PART A 9 The Endocrine System

2. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Endocrine System  Second-messenger system of the body  Uses chemical messengers (hormones) that are released into the blood  Hormones control several major processes  Reproduction  Growth and development  Mobilization of body defenses  Maintenance of much of homeostasis  Regulation of metabolism

3. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormone Overview  Hormones are produced by specialized cells  Cells secrete hormones into extracellular fluids  Blood transfers hormones to target sites  These hormones regulate the activity of other cells

4. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Chemistry of Hormones  Hormones are classified chemically as  Amino acid–based, which includes  Proteins  Peptides  Amines  Steroids—made from cholesterol  Prostaglandins—made from highly active lipids

5. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Mechanisms of Hormone Action  Hormones affect only certain tissues or organs (target cells or target organs)  Target cells must have specific protein receptors  Hormone-binding alters cellular activity

6. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Effects Caused by Hormones  Changes in plasma membrane permeability or electrical state  Synthesis of proteins, such as enzymes  Activation or inactivation of enzymes  Stimulation of mitosis  Promotion of secretory activity

7. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings The Chemistry of Hormones  Two mechanisms in which hormones act  Direct gene activation  Second-messenger system

8. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Direct Gene Activation (Steroid Hormone Action)  Diffuse through the plasma membrane of target cells  Enter the nucleus  Bind to a specific protein within the nucleus  Bind to specific sites on the cell’s DNA  Activate genes that result in synthesis of new proteins

9. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1a Nucleus Cytoplasm Steroid hormone Receptor protein Hormone-receptor complex DNA mRNA New protein Plasma membrane of target cell

10. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1a, step 1 Nucleus Cytoplasm Steroid hormone Plasma membrane of target cell

11. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1a, step 2 Nucleus Cytoplasm Steroid hormone Plasma membrane of target cell

12. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1a, step 3 Nucleus Cytoplasm Steroid hormone Receptor protein Hormone-receptor complex Plasma membrane of target cell

13. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1a, step 4 Nucleus Cytoplasm Steroid hormone Receptor protein Hormone-receptor complex DNA Plasma membrane of target cell

14. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1a, step 5 Nucleus Cytoplasm Steroid hormone Receptor protein Hormone-receptor complex DNA mRNA Plasma membrane of target cell

15. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1a, step 6 Nucleus Cytoplasm Steroid hormone Receptor protein Hormone-receptor complex DNA mRNA New protein Plasma membrane of target cell

16. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Second-Messenger System (Nonsteroid Hormone Action)  Hormone binds to a membrane receptor  Hormone does not enter the cell  Sets off a series of reactions that activates an enzyme  Catalyzes a reaction that produces a second- messenger molecule  Oversees additional intracellular changes to promote a specific response

17. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1b Cytoplasm Nonsteroid hormone (first messenger) Enzyme Receptor protein Second messenger Effect on cellular function, such as glycogen breakdown Plasma membrane of target cell ATP cAMP

18. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1b, step 1 Cytoplasm Nonsteroid hormone (first messenger) Receptor protein Plasma membrane of target cell

19. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1b, step 2 Cytoplasm Nonsteroid hormone (first messenger) Enzyme Receptor protein Plasma membrane of target cell

20. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1b, step 3 Cytoplasm Nonsteroid hormone (first messenger) Enzyme Receptor protein Second messenger Plasma membrane of target cell ATP cAMP

21. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.1b, step 4 Cytoplasm Nonsteroid hormone (first messenger) Enzyme Receptor protein Second messenger Effect on cellular function, such as glycogen breakdown Plasma membrane of target cell ATP cAMP

22. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Major Endocrine Glands and Hormones Table 9.1 (1 of 4)

23. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Major Endocrine Glands and Hormones Table 9.1 (2 of 4)

24. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Table 9.1 (3 of 4) Major Endocrine Glands and Hormones

25. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Table 9.1 (4 of 4) Major Endocrine Glands and Hormones

26. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Control of Hormone Release  Hormone levels in the blood are mostly maintained by negative feedback  A stimulus or low hormone levels in the blood triggers the release of more hormone  Hormone release stops once an appropriate level in the blood is reached

27. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Stimuli of Endocrine Glands  Most common stimuli  Endocrine glands are activated by other hormones  Examples:  Anterior pituitary hormones

28. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Stimuli of Endocrine Glands Figure 9.2a

29. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Humoral Stimuli of Endocrine Glands  Changing blood levels of certain ions stimulate hormone release  Humoral indicates various body fluids such as blood and bile  Examples:  Parathyroid hormone  Calcitonin  Insulin

30. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Humoral Stimuli of Endocrine Glands Figure 9.2b

31. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Neural Stimuli of Endocrine Glands  Nerve impulses stimulate hormone release  Most are under the control of the sympathetic nervous system  Examples include the release of norepinephrine and epinephrine by the adrenal medulla

32. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.2c Neural Stimuli of Endocrine Glands

33. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Major Endocrine Organs  Pituitary gland  Thyroid gland  Parathyroid glands  Adrenal glands  Pineal gland  Thymus gland  Pancreas  Gonads (Ovaries and Testes)  Hypothalamus

34. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Location of Major Endrocrine Organs Figure 9.3

35. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Pituitary Gland  Size of a pea  Hangs by a stalk from the hypothalamus in the brain  Protected by the sphenoid bone  Has two functional lobes  Anterior pituitary—glandular tissue  Posterior pituitary—nervous tissue  Often called the “master endocrine gland”

36. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary  Six anterior pituitary hormones  Two affect non-endocrine targets  Growth hormone  Prolactin  Four stimulate other endocrine glands (tropic hormones)  Thyroid-stimulating hormone (thyrotropic hormone)  Adrenocorticotropic hormone  Two gonadotropic hormones

37. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary  Characteristics of all anterior pituitary hormones  Proteins (or peptides)  Act through second-messenger systems  Regulated by hormonal stimuli, mostly negative feedback

38. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary Figure 9.4

39. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary  Growth hormone  General metabolic hormone  Major effects are directed to growth of skeletal muscles and long bones  Plays a role in determining final body size  Causes amino acids to be built into proteins  Causes fats to be broken down for a source of energy

40. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary  Growth hormone (GH) disorders  Pituitary dwarfism results from hyposecretion of GH during childhood  Gigantism results from hypersecretion of GH during childhood  Acromegaly results from hypersecretion of GH during adulthood

41. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary Gigantism Figure 9.5a

42. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary Dwarfism Figure 9.5b

43. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary  Prolactin (PRL)  Stimulates and maintains milk production following childbirth  Function in males is unknown  Adrenocorticotropic hormone (ACTH)  Regulates endocrine activity of the adrenal cortex  Thyroid-stimulating hormone (TSH)  Influences growth and activity of the thyroid gland

44. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Anterior Pituitary  Gonadotropic hormones  Regulate hormonal activity of the gonads  Follicle-stimulating hormone (FSH)  Stimulates follicle development in ovaries  Stimulates sperm development in testes  Luteinizing hormone (LH)  Triggers ovulation of an egg in females  Stimulates testosterone production in males

45. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Pituitary–Hypothalamus Relationship  Hormonal release is regulated by releasing and inhibiting hormones produced by the hypothalamus  Hypothalamus produces two hormones  These hormones are transported to neurosecretory cells of the posterior pituitary  Oxytocin  Antidiuretic hormone  The posterior pituitary is not strictly an endocrine gland, but does release hormones

46. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Posterior Pituitary  Oxytocin  Stimulates contractions of the uterus during labor, sexual relations, and breastfeeding  Causes milk ejection in a nursing woman

47. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Posterior Pituitary  Antidiuretic hormone (ADH)  Inhibits urine production by promoting water reabsorption by the kidneys  In large amounts, causes vasoconstriction leading to increased blood pressure  Also known as vasopressin

48. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Posterior Pituitary Figure 9.6

49. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland  Found at the base of the throat  Consists of two lobes and a connecting isthmus  Produces two hormones  Thyroid hormone  Calcitonin

50. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland Figure 9.7a

51. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland  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

52. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland Figure 9.7b

53. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland  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

54. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland Figure 9.8

55. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland  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

56. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland Figure 9.9

57. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland  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

58. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid Gland Figure 9.7b

59. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Parathyroid Glands  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

60. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Regulation of Calcium in Blood 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

61. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Regulation of Calcium in Blood Figure 9.10, step 1 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Imbalance

62. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Regulation of Calcium in Blood Figure 9.10, step 2 Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca 2+ levels Thyroid gland Imbalance

63. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Regulation of Calcium in Blood 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

64. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Regulation of Calcium in Blood 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

65. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormonal Regulation of Calcium in Blood 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

66. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.10, step 6 Calcium homeostasis of blood 9–11 mg/100 ml Falling blood Ca 2+ levels Imbalance Hormonal Regulation of Calcium in Blood

67. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.10, step 7 Calcium homeostasis of blood 9–11 mg/100 ml Thyroid gland Parathyroid glands Falling blood Ca 2+ levels Imbalance Hormonal Regulation of Calcium in Blood

68. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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 Hormonal Regulation of Calcium in Blood

69. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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 Hormonal Regulation of Calcium in Blood

70. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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 Hormonal Regulation of Calcium in Blood

71. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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 Hormonal Regulation of Calcium in Blood

72. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Adrenal Glands  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

73. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Adrenal Cortex Figure 9.11

74. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Adrenal Cortex  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)

75. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Adrenal Cortex Figure 9.12

76. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Adrenal Cortex  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

77. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response 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

78. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 1 Short term Stress Hypothalamus

79. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 2 Short term Stress Hypothalamus Nerve impulses Spinal cord

80. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 3 Short term Stress Hypothalamus Nerve impulses Spinal cord Adrenal medulla Preganglionic sympathetic fibers

81. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response 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)

82. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response 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

83. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 6 More prolonged Stress Hypothalamus

84. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 7 More prolonged Stress Hypothalamus Releasing hormone Corticotropic cells of anterior pituitary

85. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 8 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH

86. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 9 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH Mineralocorticoids Long-term stress response

87. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Roles of the Hypothalamus and Adrenal Glands in the Stress Response Figure 9.13, step 10 More prolonged Stress Hypothalamus Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH MineralocorticoidsGlucocorticoids Long-term stress response

88. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

89. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

90. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

91. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Adrenal Cortex  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

92. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Adrenal Glands  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

93. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Adrenal Glands  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

94. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Adrenal Medulla  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

95. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Adrenal Cortex Figure 9.11

96. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Pancreatic Islets  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

97. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Pancreatic Islets Figure 9.14a–b

98. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Pancreatic Islets Figure 9.14b–c

99. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

100. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.15, step 1 Homeostasis: Normal blood glucose levels (90 mg/100ml)

101. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

102. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

103. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

104. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

105. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

106. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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)

107. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

108. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

109. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

110. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

111. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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)

112. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings 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

113. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Pineal Gland  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

114. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Location of Major Endrocrine Organs Figure 9.3

115. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Thymus Gland  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

116. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Gonads  Ovaries  Produce eggs  Produce two groups of steroid hormone  Estrogens  Progesterone  Testes  Produce sperm  Produce androgens, such as testosterone

117. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Location of Major Endrocrine Organs Figure 9.3

118. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Ovaries  Estrogens  Stimulate the development of secondary female characteristics  Mature female reproductive organs  With progesterone, estrogens also  Promote breast development  Regulate menstrual cycle

119. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Ovaries  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

120. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hormones of the Testes  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

121. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Other Hormone-Producing Tissues and Organs  Parts of the small intestine  Parts of the stomach  Kidneys  Heart  Many other areas have scattered endocrine cells

122. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Other Hormone-Producing Tissues and Organs Table 9.2 (1 of 2)

123. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Table 9.2 (2 of 2) Other Hormone-Producing Tissues and Organs

124. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Endocrine Function of the Placenta  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

125. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Developmental Aspects of the Endocrine System  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

126. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings End  end