1 / 64

Adrenal gland

Adrenal gland. The adrenal cortex produces three major classes of steroids: (1) glucocorticoids (2)mineralocorticoids (3) adrenal androgens. Adrenal cortex. Zona glomerulosa (Aldrosterone) Zona Fasciculata (Cortisol) Zona reticularis( Androgen).

Télécharger la présentation

Adrenal gland

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. Adrenal gland

  2. The adrenal cortex produces three major classes of steroids: (1) glucocorticoids (2)mineralocorticoids (3) adrenal androgens

  3. Adrenal cortex • Zona glomerulosa (Aldrosterone) • Zona Fasciculata (Cortisol) • Zona reticularis( Androgen)

  4. Cholesterol, derived from the diet and from endogenous synthesis, is the substrate for steroidogenesis. • Uptake of cholesterol by the adrenal cortex is mediated by the low-density lipoprotein (LDL) receptor. • The principal glucocorticoid is cortisol (hydrocortisone).

  5. Glucocorticoid Physiology

  6. Glucocorticoid • regulation of protein, carbohydrate, lipid and nucleic acid metabolism. • Glucocorticoids raise the blood glucose by antagonizing the secretion and actions of insulin, inhibiting peripheral glucose uptake, it promotes gluconeogenesis. • protein breakdown and nitrogen excretion, inhibition of protein synthesis.

  7. Glucocorticoid • Glucocorticoids have anti-inflammatory properties. • Cortisol impairs cell mediated immunity. • Cortisol has major effects on body water. It helps regulate the Extra Cellular Fluid Volume by retarding the migration of water into cells and by promoting renal water excretion, the latter effect mediated by suppression of vasopressin secretion, by an increase in the rate of glomerular filtration, and by a direct action on the renal tubule.

  8. Mineralocorticoid Physiology

  9. Renin-Angiotensin- Aldosterone system • Renin is a proteolytic enzyme that is produced in the granules of the juxtaglomerular cells surrounding the afferent arterioles of glomeruli in the kidney. • Renin acts on the angiotensinogen (in the liver) to form the angiotensin I . • Angiotensin I is then enzymatically transformed by angiotensin-converting enzyme (ACE), which is present in many tissues (particularly the pulmonary vascular endothelium), to the angiotensin II.

  10. Angiotensin II is a potent pressor agent and exerts its action by a direct effect on arteriolar smooth muscle. • angiotensin II stimulates production of aldosterone by the zona glomerulosa of the adrenal cortex.

  11. mineralocorticoids are considered major regulators of ECFV and are the major determinants of potassium metabolism. These effects are mediated by the binding of aldosterone to the MR in epithelial cells, primarily the principal cells in the renalcortical collecting duct.

  12. Regulation of Aldosterone Secretion • renin-angiotensin system, • potassium • ACTH

  13. Potassium ion directly stimulates aldosterone secretion, independent of the circulating renin-angiotensin system, which it suppresses . • Potassium modifies aldosterone secretion indirectly by activating the local renin-angiotensin system in the zona glomerulosa.

  14. Androgen physiology

  15. Androgens regulate male secondary sexual characteristics and can cause virilizing symptoms in women. • Adrenal androgens have a minimal effect in males whose sexual characteristics are predominately determined by gonadal steroids (testosterone). • In females several androgen-like effect( sexual hair) are mediated by adrenal androgens.

  16. Hyperfunction of the Adrenal Cortex • Excess cortisol is associated with Cushing's syndrome • Excess aldosterone causes aldosteronism • Excess adrenal androgens cause adrenal virilism.

  17. Causes of Cushing's Syndrome

  18. Pituitary-hypothalamic dysfunction • Pituitary ACTH-producing micro- or macroadenomas • ACTH or CRH-producing non endocrine tumors (bronchogenic carcinoma, carcinoid of the thymus)

  19. Adrenal macronodular hyperplasia • Adrenal micronodular dysplasia • Adrenal neoplasia(adenoma or carcinoma) • Exogenous (Prolonged use of glucocorticoids or ACTH)

  20. Sign or Symptom • Typical habitus (centripetal obesity ;Increased body weight) • Fatigability and weakness • Hypertension • Hirsutism • Hypertrophy of clitoris • Amenorrhea • Broad violaceous cutaneous striae

  21. Personality changes • Ecchymoses • Proximal myopathy • Edema • Polyuria, polydipsia • Hyperglycemia

  22. Diagnosis • The diagnosis of Cushing's syndrome depends on the demonstration of increased cortisol production and failure to suppress cortisol secretion normally when dexamethasone is administered.

  23. Diagnosis • Cortisol after dexamethazone suppression test • ACTH • Urine 24 hours for cortisol • CT-scan and MRI of pituitary or adrenal

  24. Treatment of Cushing's Syndrome • Trans sphenoidal resection of pituitary microadenoma • Radiation therapy • Bilateral adrenalectomy • Medical adrenalectomy (metyrapone, mitotane, aminoglutethimide, ketoconazole)

  25. Adrenal insufficiency • Idiopathic • Infection • Surgery • Congenital • Hypothalamic and pituitary disease • exogenus

  26. Sign and Symptom • Weakness • Pigmentation of skin • Wieght loss • Anorexia,nausea and vomiting • Hypotension and syncope

  27. Diagnosis • Check sodium and potassium • blood sugar • cortisol after ACTH stimulation test

  28. ACTH stimulation test(250ug)

  29. Treatment -Steroid and mineralocorticoid

  30. Hyper Aldosteronism • Aldosteronism is a syndrome associated with hyper secretion of the mineralocorticoid aldosterone. • Inprimaryaldosteronism the cause for the excessive aldosterone production resides within the adrenal gland. • Insecondaryaldosteronism the stimulus is extra adrenal.

More Related