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Hormones of the Adrenal Cortex. Glucocorticoids Mineralocorticoids Adrenal Androgens. Adrenal Gland. The adrenal gland is composed of Cortex Medulla. Adrenal Gland. Adrenal cortex Secrete steroid hormones Glucocorticoids Cortisol Corticosterone Mineralocoticoids Aldosterone
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Hormones of the Adrenal Cortex Glucocorticoids Mineralocorticoids Adrenal Androgens Adrenocortical Hormones
Adrenal Gland • The adrenal gland is composed of • Cortex • Medulla Adrenocortical Hormones
Adrenal Gland • Adrenal cortex • Secrete steroid hormones • Glucocorticoids • Cortisol • Corticosterone • Mineralocoticoids • Aldosterone • Sex hormones • Adrenal androgens Adrenocortical Hormones
Adrenal Gland • Disorders of adrenal gland lead to endocrinopathies • Hypercorticolism • Cushing’s syndrome • Adrenal insufficiency • Addison’s disease • Hyperaldosteronism • Conn’s syndrome • Hypoaldosteronism • Androgen excess • Syndrome of congenital adrenal hyperplasia Adrenocortical Hormones
Adrenal Gland • Glucocorticoids help regulate metabolism • Carbohydrate • Proteins • Fat • Mineralocorticoids help regulate • N+ & K+ balance • ECF volume Adrenocortical Hormones
Adrenal Cortex • The adult cortex composed of 3 zones • Glomerulosa • Fasciculata • Reticularis Adrenocortical Hormones
Disorders of Adrenocortical Hormones Secretion Adrenocortical Hormones
Disorders • Hypercorticolism • Cushing’s syndrome • Adrenal insufficiency • Addison’s disease • Hyperaldosteronism • Conn’s syndrome • Hypoaldosteronism • Androgen excess • Syndrome of congenital adrenal hyperplasia Adrenocortical Hormones
Hypercortolism • Cushing’s syndrome • Condition resulting from chronic exposure to excess glucocorticoids • Cushing syndrome • ACTH dependent • ACTH independent Adrenocortical Hormones
ACTH dependent Cushing’s syndrome • Classification • ACTH dependent • Pituitary adenoma (secrete ACTH) • Cushing’s disease Adrenocortical Hormones
ACTH dependent Cushing’s syndrome • Non-pituitary neoplasm • Ectopic ACTH (lung tumours) • Chronic ACTH hypersecretion leads to • Hyperplasia of zona fasciculata & reticularis Adrenocortical Hormones
ACTH dependent Cushing’s syndrome • Iatrogenic (ACTH therapy) Adrenocortical Hormones
ACTH independent Cushing’s syndrome • Primary adrenal neoplasia • Adenoma or carcinoma • Produce excess cortisol • Suppress ACTH Adrenocortical Hormones
ACTH independent Cushing’s syndrome • Iatrogenic • Chronic glucocorticoid therapy • Leads to inhibition • ACTH • Atrophy of cortex Adrenocortical Hormones
Effects of Cortisol Excess • Affects almost all systems Adrenocortical Hormones
Effects of Cortisol Excess • Excessive physiological effects of glucocorticoids • Metabolic effects • Anti-inflammatory effects • Antigrowth effects • Stress adaptation • Vascular effects, renal effects • GIT effects • CNS effects Adrenocortical Hormones
Effects of Cortisol Excess • On connective tissue • Inhibition of fibroblasts • Loss of collagen and connective tissue • Results in • Thinning of skin • Easy bruising • Stria formation • Poor wound healing Adrenocortical Hormones
Effects of Cortisol Excess • On bone • Inhibit bone formation because • Protein synthesis, collagen • Oesteolysis • On Ca++ metabolism • Its intestinal absorption, leads to • serum Ca++ concentration • Secondary PTH secretion • urinary excretion of Ca++ • Thus a negative Ca++ balance Adrenocortical Hormones
Effects of Cortisol Excess • Blood cells • RBCs little direct effect • Leucocytes • number of polymorphnuclear cells (PMN) in circulation • number of circulating • Lymphocytes, monocytes, eosinophils • Glucocorticoids decrease migration • Inflammatory cells to site of injury Adrenocortical Hormones
Effects of Cortisol Excess • On CVS • CO, peripheral vascular tone • Glucocorticoids in excess cause • Hypertension • Regulation of renin substrate • Renal function • Mineralocorticoid effects • Na+ retention • Hypokalaemia • Hypertension Adrenocortical Hormones
Effects of Excess Androgens • Plasma levels of DHEA and androstenedione • Conversion to androgen excess • Testosterone • Dihydrotestosterone Adrenocortical Hormones
Effects of Excess Androgens • In women • Hirsutism, acne • Amenorrhoea • In men with Cushing’s syndrome • Cortisol suppress LH • Testosterone secretion (testes) • Libido, impotence Adrenocortical Hormones
Hyperaldosteronism (Conn’s Syndrome) • Excess production of mineralocorticoids • Primary hyperaldosteronism • Aldosterone secreting tumours (adenoma) • Secondary hyperaldosteronism • Renal ischaemia • Low intravascular volume • CCF, diuretic therapy, • Hypoprotenemic states (cirrhosis) Adrenocortical Hormones
Hyperaldosteronism (Conn’s Syndrome) • Manifestation • Consequences of excess aldosterone • Na+ retention • K+ & H+ wasting by kidney • Initially Na+ retention leads to • ECFV expansion • Increased CO & BP • Then Sodium escape phenomenon Adrenocortical Hormones
Hyperaldosteronism (Conn’s Syndrome) • End stage • Elevated aldosterone promote • Continued Na+ exchange for K+, H+ • There is K+ depletion and alkalosis Adrenocortical Hormones
Hypocorticolism • Adrenal insufficiency • Addison’s disease • Deficient production of • Glucocorticoids • Mineralocorticoids • Causes • Primary adrenal insufficiency • Autoimmune diseases • Malignancies • Adrenal haemorrhage • Infections – TB • Familial glucocorticoid defficiency Adrenocortical Hormones
Hypocorticolism • Secondary adrenal insufficiency • Anterior pituitary failure • Deficient secretion of ACTH by pituitary Adrenocortical Hormones
Mineralocorticoid deficiency • Lack of aldosterone secretion leads to • Decreased Na+ reabsoption by kidney • Na+, Cl-, H2O lost in urine • Fall in ECFV, dehydration • Hayponatraemia, hyperkalaemia, mild acidosis • Depletion of ECFV • Plasma volume falls • Haemoconcetration • Fall in CO • Shock Adrenocortical Hormones
Glucocorticoid deficiency • Lack of cortisol • ↓ gluconeogenesis • It will be difficult to maintain BG between meals • Lack of mobilization of proteins, fats • Individual cannot handle stress • Mild trauma can cause death • Skin pigmentation • Lack of cortisol • Lead to excess ACTH, α-MSH Adrenocortical Hormones