1. Copyright 2003 by Mosby, Inc. All rights reserved. CHAPTER 17 ENDOCRINE SYSTEM

2. Copyright 2003 by Mosby, Inc. All rights reserved. Structure and Function Primary function of the endocrine system –To produce hormones that monitor and coordinate body activities Endocrine glands secrete hormones directly into the bloodstream Three hormone categories –Tropic hormones –Sex hormones –Anabolic hormones

3. Copyright 2003 by Mosby, Inc. All rights reserved. Figure 17-1 Endocrine System

4. Copyright 2003 by Mosby, Inc. All rights reserved. Glands and Their Hormones Hypothalamus –Structure located above the pituitary gland that translates nervous system impulses into endocrine system messages Pituitary gland –Produces the hormones that regulate the secretion of other glands Pineal body –Produces the hormone melatonin

5. Copyright 2003 by Mosby, Inc. All rights reserved. Glands and Their Hormones (continued) Thyroid –Produces hormones that regulate body metabolism Parathyroid –Secretes parathyroid hormone, which affects the amount of calcium in the blood Thymus –Produces the hormone thymosin that stimulates the lymphoid organs to produce T-lymphocytes or antibodies in newborns and young children

6. Copyright 2003 by Mosby, Inc. All rights reserved. Glands and Their Hormones (continued) Pancreas –Produces the hormones insulin and glucagon. Insulin regulates transportation of sugar, fatty acids, and amino acids into the cells. Adrenal glands –Produce about 30 hormones Gonads –The primary sex glands

7. Copyright 2003 by Mosby, Inc. All rights reserved. Glands and Their Hormones (continued) Prostaglandins –Known to decrease blood pressure, cause fever, increase hydrochloric acid secretion in the stomach, increase uterine contraction during pregnancy, and influence intestinal peristalsis

8. Copyright 2003 by Mosby, Inc. All rights reserved. Hormonal Changes of Puberty Adrenal gland secretes the hormones that begin the development of secondary sexual characteristics In a man, the voice deepens and facial hair begins to grow In a woman, the breasts enlarge and fatty tissue is deposited around the hips In both men and women height and weight increase

9. Copyright 2003 by Mosby, Inc. All rights reserved. Hormonal Changes of Pregnancy The placenta, or interfacing organ between the fetal and maternal circulation, produces a hormone called human chorionic gonadotropin (hCG) Increased estrogen and progesterone from the ovaries are maintained until the placenta begins to produce these hormones Progesterone increases the mobility of the pelvic and lower back bones to allow the birthing process The pituitary and thyroid glands increase in size, resulting in a higher metabolic rate

10. Copyright 2003 by Mosby, Inc. All rights reserved. Hormonal Changes of Menopause Menopause occurs following a decrease in secretion of the gonadotropins follicle- stimulating hormone (FSH) and luteinizing hormone (LH) A decrease in the secretion of the hormone estrogen by the ovaries occurs Hot flashes, periods of feeling extreme heat, are the only universal symptom of menopause

11. Copyright 2003 by Mosby, Inc. All rights reserved. Assessment Techniques Basal metabolic rate (BMR) Protein-bound iodine (PBI) Immunoassay Radioiodine uptake (RAIU) studies Glucose tolerance testing (GTT)

12. Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Endocrine System Acromegaly –An enlargement of the bones of the hands, feet, and jaws Addison's disease –Caused by hyposecretion of the hormones produced by the cortex of the adrenal gland Cretinism –Condition resulting from a congenital deficiency of thyroid secretion or hypothyroidism

13. Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Endocrine System (continued) Cushing’s syndrome –Disorder that causes hyperactivity of the adrenal glands, which is triggered by the oversecretion of the pituitary hormone ACTH Diabetes insipidus –From an acquired or inherited decrease in the antidiuretic hormone secreted by the pituitary Diabetes mellitus –A disorder of carbohydrate, fat, and protein metabolism resulting from insufficient insulin production by the pancreas

14. Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Endocrine System (continued) Dwarfism –Results from hyposecretion of the growth hormone of the pituitary gland, which has been caused by a tumor, infection, genetic factors, or trauma Gigantism –An excessive growth of the long bones caused by hypersecretion of the somatotropic hormone Graves’ disease –Caused by hyperthyroidism or thyrotoxicosis

15. Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Endocrine System (continued) Hyperparathyroidism –Causes hypercalcemia, an increased calcium blood level Hypoglycemia –Results from increased insulin production by the pancreas Hypoparathyroidism –A decreased secretion of parathyroid hormone that causes tetany

16. Copyright 2003 by Mosby, Inc. All rights reserved. Disorders of the Endocrine System (continued) Hypothyroidism –Also called Hashimoto's disease, results from an insufficient production of thyroxine Syndrome of inappropriate antidiuretic hormone (SIAD) –Involves water intoxication and the dilution of intracellular and extracellular body tissues, usually resulting from lung cancer Virilism –Results from increased secretion in the adrenal glands

17. Copyright 2003 by Mosby, Inc. All rights reserved. Issues and Innovations Steroid abuse – Causes problems for men such as stunted growth, liver tumors, and decreased sperm production – Causes problems for women such as loss of menstrual cycle and baldness