2. Suprarenal Glands Divided into two parts; each with separate functions Suprarenal Cortex Suprarenal Medulla

3. The Adrenal Cortex Figure 25.9a

6. C. The Adrenal Glands Adrenal medulla Adrenal cortex Three specific zones and each produces a specific class of steroid hormone Zona glomerulosa – mineralocorticoids ( Aldosterone ) Zona fasciculata – glucocorticoids ( Cortisole ) Zona reticularis - androgens

7. Hormones of the Adrenal Cortex Slide 9.29a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  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

8. Hormones of the Adrenal Cortex Slide 9.29b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Sex hormones  Produced in the inner layer of the adrenal cortex  Androgens (male) and some estrogen (female)

9. Functions of mineralocorticoids Aldosterone exerts the 90% of the mineralocorticoid activity. Cortisol also have mineralocorticoid activity, but only 1/400 th that of aldosterone Aldosterone increases renal tubular (principal cells) reabsorption of sodium & secretion of potassium Excess aldosterone ↑ ECF volume & arterial pressure, but has only a small effect on plasma sodium concentration

10. Excess aldosterone causes hypokalemia & muscle weakness, & too little aldosterone causes hyperkalemia & cardiac toxicity Excess aldosterone increases tubular (intercalated cells) hydrogen ion secretion, with resultant mild alkalosis Aldosterone stimulates sodium & potassium transport in sweat glands, salivary glands, & intestinal epithelial cells Functions of mineralocorticoids

11. Effect of cortisol on protein metabolism Reduction of protein storage in all cells except those of liver – ↑ protein catabolism & ↓ protein synthesis Cortisol increases liver & plasma proteins Mobilizes aminoacids from non hepatic cells, thus increase blood amino acid level. ↑ amino acid transport to liver cells & ↓ transport of amino acids into other cells Functions of glucocorticoids

12. Figure 21.15

14. Hormones of the Adrenal Cortex Slide 9.28b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 9.10

15. Renin-angiotensin-aldosterone axis Principal factor controlling Ang II levels is renin release. Decreased circulating volume stimulates renin release via: –Decreased BP (symp effects on JGA). –Decreased [NaCl] at macula densa (“NaCl sensor”) –Decreased renal perfusion pressure (“renal” baroreceptor)

16. REGULATION OF CORTISOL SECRETION HYPOTHALAMUS CRH ANTERIOR PITUITARY ACTH ADRENAL CORTEX TARGET ORGANS CORTISOL STRESS DIURNAL RHYTHM + + - - INCREASED BLOOD GLUCOSE BLOOD AA BLOOD FATTY ACIDS

17. Pathway of RAAS

18. Figure 6.12b

19. Atrial natriuretic peptide Decreased blood pressure stimulates renin secretion

20. Renin Aldosterone Adrenal cortex Corticosterone Angiotensinogen (Lungs)  renal blood flow &/or  Na + ++ Juxtaglomerular apparatus of kidneys (considered volume receptors) Angiotensin I Converting enzymes Angiotensin II (powerful vasoconstrictor) Angiotensin III (powerful vasoconstrictor) Renin-Angiotensin System:  N.B. Aldosterone is the main regulator of Na + retention.

21. Renin-Angiotension-Aldosterone System

22. Na + Reabsorption Angiotensisn II can raise blood pressure by: –vasoconstrictor effects. –stimulating aldosterone secretion. Insert fig. 17.26

23. nephron low Blood Osmolarity blood osmolarity blood pressure ADH increased water reabsorption increase thirst renin increased water & salt reabsorption high pituitary angiotensinogen angiotensin nephron adrenal gland aldosterone JuxtaGlomerular Apparatus (JGA) Ooooooh! Zymogen!

24. Hormones of the Adrenal Medulla Slide 9.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Produces two similar hormones (catecholamines)  Epinephrine  Norepinephrine  These hormones prepare the body to deal with short-term stress

25. Effects of Epinephrine Gets you ready to fight or run Heightens your senses, tenses your muscles, openings breathing passages, etc. In response to stress Take less than 30 seconds to kick in and last several minutes

26. C. Disorders of the Adrenal Gland 1. Hypoaldosteronism loss of water/Na+ Addison’s disease – low aldosterone & cortisol 2. Hyperaldosteronism 3. Cushing’s syndrome hypersecretion of cortisol,androgens,aldosterone

27. Adrenal glands can malfunction Cushing syndrome – hypersecretion of glucocorticoids by the adrenal cortex characterized by weight gain in the trunk of the body but not arms and legs 15.4 Adrenal glands

29. Cushing’s Disease Proximal muscle wasting & weakness Osteoporosis Glucose intolerance HTN, hypokalemia Thromboembolism Depression, Psyc Infection Glaucoma

30. Adrenal glands can malfunction Addison’s disease – hyposecretion of glucocorticoids by the adrenal cortex characterized by bronzing of the skin 15.4 Adrenal glands