1. Copyright ©2011 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Medical Language, Second Edition Susan Turley CHAPTER Medical Language Second Edition Endocrinology 14

2. Endocrinology The medical specialty that studies the anatomy and physiology of the endocrine system and uses diagnostic tests, medical and surgical procedures, and drugs to treat endocrine system diseases.

3. Figure 14-1 Endocrine system

4. Anatomy and Physiology The endocrine system includes: – Hypothalamus – Pituitary gland – Pineal gland – Thyroid gland – Parathyroid glands

5. Anatomy and Physiology The endocrine system includes: – Thymus – Pancreas – Adrenal glands – Ovaries – Testes

6. Anatomy and Physiology (cont’d) All endocrine glands are alike in these ways: – They secrete substances known as hormones. – They secrete their hormones directly into the blood and not through ducts. – Their hormones regulate specific body functions.

7. Anatomy and Physiology (cont’d) One of the functions of the endocrine system is to keep the body in homeostasis by regulating body fluids, electrolytes, glucose, cellular metabolism, growth, and the wake- sleep cycle.

8. Anatomy and Physiology (cont’d) Some endocrine glands do “double duty” as part of another body system, such as the nervous system (hypothalamus and posterior pituitary gland), immune system (thymus), the digestive system (pancreas), or the genital and reproductive system (ovaries, testes).

9. Anatomy of the Endocrine System Hypothalamus – Located in the brain just below the thalamus – Functions as part of both the nervous system and the endocrine system – Secretes substances that stimulate or inhibit the secretion of hormones from the anterior pituitary gland – Produces hormones ADH and oxytocin

10. Figure 14-2 Endocrine glands in the brain

11. Anatomy of the Endocrine System (cont’d) Pituitary Gland – Located in the brain at the end of the stalk from the hypothalamus – Known as the master gland of the body – Contains two different glands that function independently of each other: the anterior pituitary gland and the posterior pituitary gland

12. Anatomy of the Endocrine System (cont’d) The anterior pituitary gland secretes seven hormones: – Thyroid-stimulating hormone (TSH) – Follicle-stimulating hormone (FSH) – Luteinizing hormone (LH) – Prolactin – Adrenocorticotropic hormone (ACTH) – Growth hormone (GH) – Melanocyte-stimulating hormone (MSH)

13. Figure 14-3 Hormones of the anterior and posterior pituitary gland

14. Anatomy of the Endocrine System (cont’d) The posterior pituitary gland secretes two hormones that are produced in the hypothalamus. – Antidiuretic hormone (ADH) – Oxytocin

15. Anatomy of the Endocrine System (cont’d) Pineal Gland – Located between the two lobes of the thalamus – Secretes the hormone melatonin – Maintains the body’s internal clock and regulates the onset and duration of sleep

16. Anatomy of the Endocrine System (cont’d) Thyroid Gland – An irregularly shaped gland that has two lobes connected by a thin bridge of tissue (the isthmus) – Located in the neck on either side of the trachea and across its anterior surface

17. Anatomy of the Endocrine System (cont’d) The thyroid gland secretes three hormones: – T 3 or triiodothyronine – T 4 or thyroxine – Calcitonin When the thyroid gland is functioning properly, this steady state is known as euthyroidism.

18. Figure 14-4 Thyroid gland and parathyroid glands

19. Anatomy of the Endocrine System (cont’d) Parathyroid Glands – Four tiny glands – Located on the posterior surface of the thyroid gland, two on each lobe – Secrete parathyroid hormone, which regulates the amount of calcium in the blood

20. Anatomy of the Endocrine System (cont’d) Thymus Gland – A pink gland with two lobes located in the thoracic cavity posterior to the sternum – Large during childhood and puberty but shrinks during adulthood – Functions as part of both the body’s immune response and the endocrine system – Secretes thymosin

21. Anatomy of the Endocrine System (cont’d) Pancreas – A yellow, elongated, triangular gland located posterior to the stomach – Functions as part of both the digestive system and the endocrine system – Secretes the hormones glucagon, insulin, and somatostatin from a group of cells known as the islets of Langerhans

22. Figure 14-5 Pancreas

23. Anatomy of the Endocrine System (cont’d) Adrenal Glands – Contains two different glands draped over the superior end of each kidney. – Each gland has an outer layer (cortex) and an inner layer (medulla). – Each layer functions independently of the other and secretes its own hormones.

24. Figure 14-6 Adrenal gland

25. Anatomy of the Endocrine System (cont’d) Adrenal Cortex – Secretes three groups of hormones: Mineralocorticoids―Aldosterone Glucocorticoids―Cortisol Androgens―Male sex hormones (in the blood, some of the androgens are changed to estrogens, female sex hormones)

26. Anatomy of the Endocrine System (cont’d) Adrenal Medulla – Secretes the hormones epinephrine and norepinephrine into the blood when the gland is stimulated by a nerve impulse

27. Anatomy of the Endocrine System (cont’d) Ovaries – Small, egg-shaped glands located in the pelvic cavity – Function as part of both the female reproductive system and the endocrine system

28. Anatomy of the Endocrine System (cont’d) Ovaries – Follicles of the ovary secrete estradiol, the most abundant and most biologically active female hormone – The corpus luteum (ruptured ovarian follicle) secretes estradiol and progesterone. – Cells around the follicle secrete testosterone

29. Anatomy of the Endocrine System (cont’d) Testes – Egg-shaped glands located outside the body in the scrotum – Function as part of both the male genitourinary system and the endocrine system – Seminiferous tubules produce spermatozoa – Secrete testosterone, the most abundant and biologically active of all the androgens

30. Anatomy of the Endocrine System (cont’d) Physiology of Hormone Response and Feedback – The endocrine system uses hormones as chemical messengers. – Some neurotransmitters (epinephrine and norepinephrine) are also hormones because they are secreted by a gland and travel in the blood. – Hormones target specific glands or organs with receptors to which they can bind.

31. Anatomy of the Endocrine System (cont’d) Synergism − When two hormones work in conjunction with one another to accomplish an enhanced effect. Antagonism − When two hormones exert an opposite effect. The endocrine system maintains body homeostasis through the use of hormones and a negative feedback mechanism.

32. Figure 14-7 Effects of hormones

33. Diseases and Conditions Anterior Pituitary Gland: All Hormones – Hyperpituitarism – Hypopituitarism – Dwarfism

34. Diseases and Conditions (cont’d) Anterior Pituitary Gland: Prolactin – Galactorrhea – Failure of lactation

35. Diseases and Conditions (cont’d) Anterior Pituitary Gland: Growth Hormone – Gigantism – Acromegaly – Dwarfism

36. Figure 14-8 Gigantism CORBIS-NY

37. Figure 14-9 Acromegaly NMSB/Custom Medical Stock Photo, Inc.

38. Diseases and Conditions (cont’d) Posterior Pituitary Gland: Antidiuretic Hormone (ADH) – Syndrome of inappropriate ADH (SIADH) – Diabetes insipidus (DI)

39. Diseases and Conditions (cont’d) Posterior Pituitary Gland: Oxytocin – Uterine inertia – Postpartum hemorrhage

40. Diseases and Conditions (cont’d) Pineal Gland: Melatonin – Seasonal affective disorder (SAD)

41. Diseases and Conditions (cont’d) Thyroid Gland: T 3 and T 4 Thyroid Hormones – Hyperthyroidism Thyrotoxicosis Graves’ disease

42. Figure 14-10 Exophthalmos Custom Medical Stock Photo, Inc.

43. Figure 14-11 Goiter Marka/Custom Medical Stock Photo, Inc.

44. Figure 14-12 Physical examination of the thyroid gland Pearson Education/PH College

45. Diseases and Conditions (cont’d) Thyroid Gland: T 3 and T 4 Thyroid Hormones (cont’d) – Goiter or thyromegaly

46. Diseases and Conditions (cont’d) Thyroid Gland: T 3 and T 4 Thyroid Hormones (cont’d) – Hyperthyroidism – Hypothyroidism

47. Diseases and Conditions (cont’d) Thyroid Gland: T 3 and T 4 Thyroid Hormones (cont’d) – Hypothyroidism – Thyroid carcinoma – Thyroiditis

48. Diseases and Conditions (cont’d) Parathyroid Glands: Parathyroid Hormone – Hyperparathyroidism – Hypoparathyroidism

49. Diseases and Conditions (cont’d) Pancreas: Insulin – Hyperinsulinism – Insulin resistance syndrome

50. Diseases and Conditions (cont’d) Pancreas: Insulin (cont’d) – Diabetes Mellitus (DM) – Ketoacidosis

51. Table 14-1 Diabetes Mellitus

52. Diseases and Conditions (cont’d) Adrenal Cortex: Aldosterone – Hyperaldosteronism – Hypoaldosteronism

53. Diseases and Conditions (cont’d) Adrenal Cortex: Cortisol – Cushing’s syndrome – Addison’s disease

54. Figure 14-13 Cushing’s syndrome (a) Biophoto Associates / Science Source / Photo Researchers, Inc.

55. Diseases and Conditions (cont’d) Adrenal Cortex: Androgens – Adrenogenital syndrome

56. Diseases and Conditions (cont’d) Adrenal Medulla: Epinephrine and Norepinephrine – Pheochromocytoma

57. Diseases and Conditions (cont’d) Ovaries: Estradiol and Progesterone – Precocious puberty – Infertility – Menopause

58. Diseases and Conditions (cont’d) Testes: Testosterone – Precocious puberty – Gynecomastia – Infertility

59. Laboratory and Diagnostic Procedures Blood Tests – Antithyroglobulin antibodies – Calcium – Cortisol level

60. Laboratory and Diagnostic Procedures (cont’d) Blood Tests (cont’d) – Fasting blood sugar (FBS) – FSH assay and LH assay – Glucose self-testing

61. Figure 14-14 Blood glucose monitor Pearson Education/PH College

62. Laboratory and Diagnostic Procedures (cont’d) Blood Tests (cont’d) – Glucose tolerance test (GTT) – Growth hormone

63. Blood Tests (cont’d) – Hemoglobin A 1c (HbA 1c ) – Testosterone – Thyroid function tests (TFTs) Laboratory and Diagnostic Procedures (cont’d)

64. Urine Tests – ADH stimulation test – Estradiol – Urine dipstick – Vanillylmandelic acid (VMA) Laboratory and Diagnostic Procedures (cont’d)

65. Radiology Tests – Radioactive iodine uptake (RAIU) and thyroid scan Laboratory and Diagnostic Procedures (cont’d)

66. Figure 14-15 Thyroid scan Custom Medical Stock Photo, Inc.

67. Medical and Surgical Procedures Medical Procedures – ADA diet

68. Medical and Surgical Procedures (cont’d) Surgical Procedures – Adrenalectomy – Fine-needle biopsy

69. Medical and Surgical Procedures (cont’d) Surgical Procedures (cont’d) – Parathyroidectomy – Thymectomy – Thyroidectomy – Transsphenoidal hypophysectomy

70. Drug Categories These categories of drugs are used to treat endocrine Diseases and Conditions: – Antidiabetic drugs – Antithyroid drugs – Corticosteroid drugs – Growth hormone drugs – Insulin – Thyroid supplement drugs

71. Figure 14-16 Insulin injection Custom Medical Stock Photo, Inc.

72. Figure 14-17 Humulin R insulin SIU BioMed/Custom Medical Stock Photo, Inc.

73. Abbreviations