Addisons’s disease is associated with all except –
Correct Answer: Low renin levels
Description: Ans. is 'd' i.e. low rennin levels The normal serum cortisol ranges between 5-23 mg/dlIn Addison's disease the cortisol level is usually below (< 3 mg/dL).Patients tend to be hypotensive and orthostatic, about 90% have systolic blood pressure under 110 mm Hg. Diastolic blood pressure is also decreased, the B.P. is usually in the range of 80/50 or less.* In Addison's diseases the heart is usually small Q.In Addison 's disease the plasma renin activity is usually elevated, - It indicates the presence of depleted intravascular volume.Addison's diseaseThe predominant manifestations in Addison's disease occur due to mineralocorticoid deficiency but the symptoms are also contributed by glucocorticoid deficiency and increased ACTHFEATURES OF:-Mineralocorticoid deficiency -lack of aldosterone secretion greatly decreases renal tubular sodium reabsorption and consequently allows sodium ions, chloride ions and water to be lost into urine in great profusion. The net result is greatly decreased extracellular fluid volume.Furthermore, hyponatremia Q, hyperkalemia Q and mild acidosis1 develop because of failure of potassium and hydrogen ions to be secreted in exchange for sodium reabsorption.Glucocorticoid deficiency -Loss of cortisol secretion leads to hypoglycaemia because of decreased gluconeogenesis and increased peripheral utilization of glucose.Furthermore, lack of cortisol reduces Q the mobilization of both proteins and fats from the tissues thereby depressing many other metabolic functions of the body. This sluggishness of energy mobilization when cortisol is not available is one of the major detrimental effects of glucocorticoid lack.Increased ACTH -When cortisol secretion is depressed the normal negative feedback to the hypothalamus and anterior pituitary gland is also depressed, therefore allowing tremendous rates of ACTH secretion as well as simultaneous secretion of increased amount of MSH.* Probably the tremendous amount of ACTH cause most of the pigmenting effect because they can stimulate formation of melanin by the melanocytes in the same way that MSH does.REMEMBER * The clinical features and laboratory features described above are characteristically seen only in primary Addison's disease because in primary Addison's disease both aldosterone and glucocorticoid are deficient,whereas * In secondary Addison's disease only glucocorticoid deficiency is seen."ALSO KNOWThe basis for acute adrenal deficiency or addisonian crisisDuring conditions of physical or mental stress, large amount of glucocorticoids are secreted to cope up with the situation. But in persons with Addison's disease, the output of glucocorticoids does not increase during stress.* Thus the deficiency of glucocorticoids, when a person actually has acute need for the excessive amount of glucocorticoids produces addisonian crisis.The manifestations are produced due to extracellular fluid dehydration and low blood volume leading to circulatory shock.
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