1. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Chapter 23  Adrenal glands  Thyroid hormones  Growth hormone  Tissue and bone growth  Calcium balance

2. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Review of Endocrine Principles  Hypothalamic-pituitary control system  Several hormones controlled by hypothalamic and anterior pituitary trophic hormones  Feedback patterns  Negative feedback:  Simple Pathway-Blood glucose level decreasing shuts off insulin secretion  Complex Pathway-use the hypothalamic-pituitary control system, where the feedback signal may be the hormone itself  Hormone receptors  May be on surface or inside the cell  Cellular responses  Target cells respond by altering existing proteins or making new proteins  Magnitude of target cell response  Depends on number of receptors and amount of active hormone  Endocrine pathologies  Excess hormone secretion  Inadequate hormone secretion  Abnormal target cell response to the hormone

3. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Adrenal Glands Structure and function of the adrenal gland Figure 23-1a

4. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-1b Adrenal Glucocorticoids

5. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-1c Adrenal Glands

6. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Adrenal Cortex Secretes Steroid Hormones 1.Aldosterone (Mineralcorticoid) 2.Glucocorticoids  Cortisol 3.Sex Hormones

7. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-2 Adrenal Glucocorticoids Synthesis pathways for steroid hormones

8. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-3 Cortisol The HPA pathway for the control of cortisol secretion Corticotropin Releasing Hormone Adrenocorticotropic Hormone

9. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-4 Circadian Rhythm of Cortisol Secretion

10. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Cortisol

11. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Cortisol  Promotes gluconeogenesis  Causes breakdown of skeletal muscle proteins  Enhances lipolysis  Suppresses the immune system  Causes negative calcium balance  Influences brain function

12. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Cortisol: Therapeutic Drug  Suppresses the immune system  Inhibits the inflammatory response  Used to treat  Bee stings, poison ivy, and pollen allergies  Prevents rejection of transplanted organs

13. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Hypercortisolism Hypercortisolism: Excess cortisol in the body Cushings Syndrome: Hormonal disorder caused by prolonged exposure to excess cortisol (including iatrogenic).  Signs and Symptoms  Hyperglycemia  Muscle protein breakdown  Excess deposits of extra fat in trunk and face  Thin arms and legs  Thin skin and bruising Three causes of hypercortisolism:  Adrenal tumor that autonomously secretes cortisol (Primary Hypercortisolism)  Pituitary tumor that autonomously secretes ACTH (Secondary Hypercortisolism or Cushing’s Disease)  Iatrogenic hypercortisolism

14. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-5 Hypercortisolism

15. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Hypocortisolism  Less common than Cushing’s syndrome  Addison’s disease  Hyposecretion of all adrenal steroid hormones  Autoimmune destruction of adrenal cortex

16. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid: Structure Figure 23-7a

17. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid: Structure Figure 23-7b

18. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-8 Thyroid Thyroid hormones are made from iodine and tyrosine

19. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Thyroid

20. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Hyperthyroidism  Increases oxygen consumption and metabolic heat production  Increase protein catabolism and may cause muscle weakness  Hyperexcitable reflexes and psychological disturbances  Influence  -adrenergic receptors in the heart

21. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Hypothyroidism  Slow metabolic rate and oxygen consumption  Decreases protein synthesis  Slowed reflexes, slow speech and thought processes, and feelings of fatigue  Cretinism in infants  Bradycardia

22. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-12 Pathway of Thyroid Hormone Control

23. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-13 Thyroid A man with goiter due to excessive TSH stimulation

24. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-14a Thyroid Goiter can occur in both hyperthyroidism and hypothyroidism

25. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-14b Thyroid

26. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Normal Growth  Growth hormone and other hormones  An adequate diet  Absence of stress  Genetics

27. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-16 Pathway of Growth Hormone Control

28. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Growth Hormone

29. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Growth Hormone  Severe GH deficiency leads to dwarfism  Oversecretion of GH in children leads to giantism  Oversecretion of GH in adults leads to acromegaly

30. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-17 Three Individuals with Acromegaly

31. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-19 Bone growth Linear growth of long bones takes place at the epiphyseal plates Epiphysis is the end of a long bone. Diaphysis is the shaft of a long bone. Epiphyseal plate is the site of bone growth. Diaphysis Compact bone Osteoblast Direction of growth Chondrocyte Cartilage owth Newly calcified bone Bonegr Dividing chondrocytes add length to bone. Chondrocytes produce cartilage. Old chondrocytes disintegrate. Osteoblasts lay down bone on top of cartilage.

32. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-19 (1 of 5) Bone growth Epiphysis is the end of a long bone. Diaphysis is the shaft of a long bone. Epiphyseal plate is the site of bone growth. Diaphysis

33. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-19 (2 of 5) Bone growth Epiphysis is the end of a long bone. Diaphysis is the shaft of a long bone. Epiphyseal plate is the site of bone growth. Diaphysis Compact bone Chondrocyte Dividing chondrocytes add length to bone.

34. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-19 (3 of 5) Bone growth Epiphysis is the end of a long bone. Diaphysis is the shaft of a long bone. Epiphyseal plate is the site of bone growth. Diaphysis Compact bone Chondrocyte Cartilage Dividing chondrocytes add length to bone. Chondrocytes produce cartilage.

35. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-19 (4 of 5) Bone growth Epiphysis is the end of a long bone. Diaphysis is the shaft of a long bone. Epiphyseal plate is the site of bone growth. Diaphysis Compact bone Chondrocyte Cartilage Dividing chondrocytes add length to bone. Chondrocytes produce cartilage. Old chondrocytes disintegrate.

36. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-19 (5 of 5) Bone growth Epiphysis is the end of a long bone. Diaphysis is the shaft of a long bone. Epiphyseal plate is the site of bone growth. Diaphysis Compact bone Osteoblast Direction of growth Chondrocyte Cartilage owth Newly calcified bone Bonegr Dividing chondrocytes add length to bone. Chondrocytes produce cartilage. Old chondrocytes disintegrate. Osteoblasts lay down bone on top of cartilage.

37. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Calcium Balance

38. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Calcium  Important signal molecule  Part of intercellular cement that holds cells together at tight junction  Cofactor in the coagulation cascade  Affects the excitability of neurons

39. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-20 Calcium Balance in the Body Ca 2+ Small intestine Dietary calcium Calcium in feces [free Ca 2+ ] 0.001 mM Kidney Ca 2+ in urine Ca 2+ in kidney tubules Calcitrol (PTH, prolactin) Active transport Some calcium is secreted into the small intestine. Cells [Ca 2+ ] 2.5 mM Passive filtration Calcitonin Ca 2+ PTH Calcitonin PTH Calcitriol Cortisol Bone ECF Electrochemical gradient PTH = parathyroid hormone KEY

40. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-20 (1 of 5) Calcium Balance in the Body [Ca 2+ ] 2.5 mM ECF PTH = parathyroid hormone KEY

41. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-20 (2 of 5) Calcium Balance in the Body [free Ca 2+ ] 0.001 mM Active transport Cells [Ca 2+ ] 2.5 mM ECF Electrochemical gradient PTH = parathyroid hormone KEY

42. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-20 (3 of 5) Calcium Balance in the Body [free Ca 2+ ] 0.001 mM Active transport Cells [Ca 2+ ] 2.5 mM Calcitonin Ca 2+ PTH Calcitriol Cortisol Bone ECF Electrochemical gradient PTH = parathyroid hormone KEY

43. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-20 (4 of 5) Calcium Balance in the Body Ca 2+ Small intestine Dietary calcium [free Ca 2+ ] 0.001 mM Calcitrol (PTH, prolactin) Active transport Cells [Ca 2+ ] 2.5 mM Calcitonin Ca 2+ PTH Calcitriol Cortisol Bone ECF Electrochemical gradient PTH = parathyroid hormone KEY

44. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-20 (5 of 5) Calcium Balance in the Body Total body calcium = intake  output Ca 2+ Small intestine Dietary calcium Calcium in feces [free Ca 2+ ] 0.001 mM Kidney Ca 2+ in urine Ca 2+ in kidney tubules Calcitrol (PTH, prolactin) Active transport Some calcium is secreted into the small intestine. Cells [Ca 2+ ] 2.5 mM Passive filtration Calcitonin Ca 2+ PTH Calcitonin PTH Vitamin D Cortisol Bone ECF Electrochemical gradient PTH = parathyroid hormone KEY

45. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-21 Calcium Balance Osteoclasts are responsible for bone resorption

46. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Calcium Balance  Parathyroid hormone  Mobilizes calcium from bone  Enhances renal reabsorption  Indirectly increases intestinal absorption  Vitamin D (Calcitriol)  Calcitonin (from Thyroid)

47. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-22 Calcium Balance: Parathyroid Glands

48. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Calcium Balance

49. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-23 Endocrine Control of Calcium Balance

50. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Calcitonin

51. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23-24 Osteoporosis Normal bone (left) and bone loss in osteoporosis (right)