1. ADRENAL GLAND

2. (A) Position of adrenal gland (B) Anatomical structure (C) Hormones & Disorders

3. TT here are two adrenal glands. The two glands have a similarity in anatomical structure, function, secreted hormones and almost in every thing. TT he two glands are located above the two kidneys, i.e. one gland above each kidney ; exactly at the position of 12 th thoracic vertebra. (A) Position

5.  S o, adrenal glands are also termed, suprarenal glands  T he term (suprarenal) comes from the anatomic description of the position of the glands as ( supra means above ) while ( renal means belongs to kidney ).  O n the other side, the term (adrenal) comes from the fact that these glands secrete the hormone (adrenaline) in cases of stress.

6.  Adrenal gland consists of two distinct parts ; Cortex and Medulla.  These two parts differ in their anatomical structure and in their functions (Hormones). (B) Structure

7. Cross – sectional view of the adrenal gland

9.  A A drenal cortex is devoted to the synthesis of CORTICOSTEROID HORMONES due to the presence of large amounts of fats specially cholesterol w hich is the precursor of these hormones. AA drenal cortex exhibits a functional zonation into three distinct zones ;

10. (1)Zona glomerulosa (2)Zona fasciculata (3)Zona reticularis

11. (1) Zona glomerulosa

12. Aldosterone

13.  Aldosterone hormone is a derivative of cholesterol.  Its normal level is about ( 4-9 Mg per 100 ml blood ).  About 2-18 Mg of aldosterone are wasted with urine daily.  Aldosterone acts on kidneys to provide active reabsorption of sodium and passive absorption of water. (increases blood pressure)  In addition to that, it causes secretion of both potassium ions and protons from the collecting ducts and distal tubules.

14. Factors affecting secretion of aldosterone (1)Angiotensin II. (2)Adrenocrticotropic hormone (ACTH). (3)Blood level of Na and K ions.

15. DISORDERS OF ALDOSTERONE (A) Natural increase i n cases o f, ( 1 ) Deficiency of sodium and plenty of potassium in the diet. ( 2 ) Heavy sweat. (B) Natural decrease i n cases of, ( 1 ) Deficiency of potassium in the diet. ( 2 ) Having large amounts of water and drinks.

16. (C) Addison disease O ccurs when about 90% of cortex cells are damaged. So, it is very rare ( 8 / million person ). A ddisonian has a remarkable depression in aldosterone level which is accompanied by a low blood pressure, high temperature, weight loss, decreased blood sodium and increased blood potassium.

17. (D) Conn disease O ccurs due to increased activity of zona glomerulosa. L eads to increased secretion of aldosterone which results in a high blood pressure, low blood potassium and high blood sodium levels.

18. (2) Zona fasciculata

19. Cortisol

20.  It is usually referred to as the “ stress hormone ” as it is involved in response to stress and anxiety.  Its primary function is to increase blood sugar and stores of sugar in the liver as glycogen.  Cortisol also can suppress immune system.  Zona fasciculata can produce (7-7.5 mg/day) of cortisol hormone.  Highest amount of cortisol can be reached in the early morning ( 165-744 nM ) while the lowest amount occurs approximately at the midnight ( 83- 358 nM ).

21. Factors affecting cortisol secretion ( 1 ) Corticotropin releasing hormone (CRH)  T his hormone controls secretion of adrenocorticotropic hormone (ACTH). It is secreted from hypothalamus. (2) Adrenocorticotrpic hormone (ACTH)  W hich is responsible for delivery of calcium ions to cortisol secreting cells in the adrenal cortex.

22. Physiological effects of cortisol ( 1 ) Anti – insulin effect. cortisol contributes to “hyperglycemia” by stimulation of hepatic gluconeogenesis and inhibition of peripheral utilization of glucose. ( 2 ) It increases gastric acid secretion. ( 3 ) It cooperates with adrenaline to create memories of short – term events. ( 4 ) It has an anti – inflammatory action as inhibits secretion of histamine from basophils and mast cells.

23. ( 5 ) Elevates blood pressure. ( 6 ) Stimulates hepatic detoxification by inducing ; - Tryptophan oxygenase to reduce serotonin level in the brain. - Glutamine synthase to reduce glutamate level in the brain. ( 7 ) Suppresses immune system. ( 8 ) It inhibits secretion of CRH resulting in a feed – back inhibition for ACTH.

24. Disorders of cortisol (1) Cushing syndrome A hormone disorder caused by high levels of cortisol in the blood. I t may be caused by ; ( 1 ) Taking glucocorticoid drugs. ( 2 ) Tumors in cortisol secreting cells. ( 3 ) Tumors in ACTH secreting cells. C ushing syndrome is not confined to humans but relatively common in domestic animals.

25. Symptoms of Cushing syndrome include ; ( 1 ) Rapid weight gain specially from face, trunk and limbs. ( 2 ) very high blood sugar which may lead to diabetes mellitus. ( 3 ) High blood pressure (secondary). ( 4 ) Osteoporosis due to increased protein breakdown. C ushing syndrome can be treated by surgery.

27. ( 2 ) Addison disease Deficiency in cortisol level in the blood. Leads to ; ( 1 ) Low blood sugar. ( 2 ) Low blood pressure. ( 3 ) High potassium levels in the blood. ( 4 ) Full body weakness.

28. (3) Zona reticularis

29. Testosterone

30.  Testosterone is secreted in both males and females, but in males in a larger amount so, its effects appear clearly on males and therefore, it is the “masculinity hormone”  In males, it is secreted mainly from Leyding cells in the testes, and a small amount from adrenal reticularis.  In females, it is secreted from Thecal cells in the ovaries, placenta and a small amount from adrenal reticularis.  Its activity is mediated by LH and FSH.

31. D H E A

32. Physiological effects of testosteron After puberty, testosteron amount in the body increases to cause ; ( 1 ) Development and growth of reproductive organs. ( 2 ) Appearence of secondary sex characteristics such as ; deepening in voice, growth of beard, growth of Adam apple, increase in height, ….etc. ( 3 ) Maintains males fertility.

33. Estradiol

34.  Estradiol is the predominant sex hormone in females.  It is produced primarily by granulosa cells in ovaries, in addition to small amount from adrenal reticularis.  During pregnancy, its amount increases due to secretion from placenta also.  It is present in males but in lower amounts than females.  Its activity is mediated by LH and FSH.

35. D H E A - S

36. Physiological effects of estradiol ( 1 ) Growth of female reproductive organs. ( 2 ) Maintaining of oocytes in ovaries. ( 3 ) During pregnancy, it promotes uterine blood flow and stimulates breast growth. ( 4 ) Regulation of menstrual cycle. ( 5 ) Affects liver to synthesize lipoproteins, binding proteins and proteins of blood clotting.

37.  Adrenal medulla is the second part of adrenal gland.  Devoted to synthesis of catecholamines which include adrenaline ( epinephrine ) and noradrenaline ( norepinephrine ).  Both hormones are secreted in stressful situations. Medulla

38. Physiological effects of catecholamines Catecholamines causes general physiological changes that prepare the body for physical activities. In case of ( fight or flight ), catecholamines cause ; ( 1 ) Elevation of blood pressure. ( 2 ) Increasing blood sugar. ( 3 ) Increasing heart rate. ( 4 ) Increased metabolic rate. ( 5 ) Affects peripheral nervous system.

39. pheochromocytoma Very rare state. A tumor In the adrenal medulla that causes hypersecretion of catecholamines which leads to ; ( 1 ) Hypertension. ( 2 ) Very high blood sugar. ( 3 ) High rate of heartbeat.