Chapter_49 intro to endocrine general .pptx

Introduction to the endocrine system

1. Timby’s Introductory Medical-Surgical Nursing, 13e Chapter 49: Introduction to the Endocrine System

2. A&P the Endocrine System

3. ANATOMY AND PHYSIOLOGY: Endocrine Glands Stimulated by pituitary gland (hypophysis) Secrete hormones directly into the bloodstream Differ from exocrine glands Play a vital role in regulating homeostatic processes of Metabolism, growth, fluid, electrolyte balance Reproductive processes, sleep and awake cycles See Table 49-1

4. Question #1 Is the following statement true or false? Endocrine glands secrete hormones into a duct.

5. Answer to Question #1 False Rationale: Exocrine glands secrete hormones into a duct; endocrine glands secrete hormones directly into the bloodstream.

6. Pituitary Gland Connected by stalk to hypothalamus Three lobes Called the “master gland” because it regulates function of other endocrine glands This name is misleading because pituitary is influenced by the hypothalamus.

7. Hypothalamus Located between cerebrum and brain stem Influences pituitary gland Creates pathway for neurohormones Stimulate, inhibit pituitary gland secretions

8. Hypothalamus Hormone Regulation Feedback loop controls hormone levels Most hormones secreted in response to negative feedback Most endocrine disorders: overproduction or underproduction of specific hormones

9. Question #2 Is the following statement true or false? The hypothalamus creates pathways for neurohormones.

10. Answer to Question #2 True Rationale: The hypothalamus creates pathways for neurohormones that stimulate and inhibit secretions from anterior and posterior lobes of the pituitary gland.

11. Hypothalamic Hormones These hormones are secreted by the hypothalamus and act on the anterior pituitary via the hypophyseal portal system. TRH CRH GnRH GHRH Somatostatin Hypothalamic dopamine

12. Thyroid and Parathyroid Glands Thyroid Gland: in lower neck anterior to trachea “Isthmus” joins two lateral lobes Function of tetraiodothyronine (T 4 ), triiodothyronine (T 3 ), and calcitonin

13. Thyroid and Parathyroid Glands Parathyroid Glands: small, bean-shaped bodies Embedded within lateral lobes of the thyroid Parathormone Causing calcium and phosphorus to be released from bones; interfering with the urinary excretion of calcium but promoting the urinary excretion of phosphorus; and activating vitamin D, causing an increase in calcium absorption within the intestine.

14. Thymus Gland In upper part of the chest above or near the heart Secretes thymosin and thymopoietin Large during childhood but usually shrinks by adulthood Production of T lymphocytes decreases with age Functional disorders are rare

15. Pineal and Adrenal Glands Pineal Gland: attached to the thalamus Function of melatonin

16. Pineal and Adrenal Glands Adrenal Glands: located above the kidneys Adrenal cortex secretes corticosteroids Function of corticosteroids Adrenal medulla secretes epinephrine and norepinephrine Fight-or-flight response

17. Pancreas and Gonads Pancreas: below the stomach with head of gland close to the duodenum Both an exocrine and an endocrine gland Exocrine portion secretes digestive enzymes Islets of Langerhans: beta cells (insulin); alpha cells (glucagon)

18. Pancreas and Gonads Ovaries, testes: importance of sex glands Secretion of testosterone, estrogen, and progesterone

19. Question #3 Is the following statement true or false? The pancreas has both exocrine and endocrine glands.

20. Answer to Question #3 True The pancreas has both exocrine (delivers hormones via ducts) and endocrine (delivers hormones directly into bloodstream) glands.

21. Additional Hormone-Releasing Organs Atria of heart: atrial natriuretic peptide Kidneys: renin; erythropoietin Skin Function of placenta and its secretion of hormones Gastrointestinal structures

22. Assessment #1 History Physical Examination Diagnostic Findings Blood count and chemistry profile Hormone levels Cortisol, antidiuretic hormone, testosterone TSH, T 3 , and T 4

23. Assessment #2 Diagnostic Findings—(cont.) Radiography CT scan MRI Nursing Management