The adrenal glands, which are located at the proximal renal pole of each kidney, consist of cortex medulla The adrenal cortex and the adrenal medulla both have different endocrine functions. Adrenal adrenal cortex The adrenal cortex produces glucocorticoids (primarily cortisol) mineralocorticoids (primarily aldosterone) androgens (primarily dehydroepiandrosterone and androstenedione). Glucocorticoids induce and inhibit gene transcription in many cells and organ systems. Other outstanding effects are anti-inflammatory effects and an increase in hepatic gluconeogenesis. Mineralocorticoids regulate electrolyte transport across epithelial membranes. Particularly noteworthy here is the renal sodium conservation in exchange for potassium. The main physiological effect of adrenal androgens takes place only after their conversion to testosterone and dihydrotestosterone. The physiology of the hypothalamic-pituitary-adrenal system will be further discussed elsewhere. Adrenal medulla The adrenal medulla consists of chromaffin cells that synthesize and secrete catecholamines (mainly adrenaline and to a lesser extent norepinephrine). Chromaffin cells also bioactive amines and peptides (eg. As histamine, serotonin, Chromogranin, neuropeptide hormone) ago. Epinephrine and norepinephrine, the main amines in the sympathetic nervous system are responsible for the so-called. Fight-or-flight reaction (eg. As chronotropic and inotropic effects on the heart, bronchodilation, vasoconstriction peripheral and splanchnic with simultaneous vasodilation in the skeletal muscles and metabolic effects such as glycogenolysis, lipolysis and renin release). Clinical Syndromes Most adrenal deficiency syndromes affect all adrenocortical hormones. The sub-function may be primary (a malfunction of the adrenal gland itself as in Addison’s disease) or secondary (due to lack of stimulation of the adrenal gland by the pituitary or hypothalamus). Hypothalamic disorder is sometimes called tertiary. Adrenal overactivity causes different clinical symptoms, depending on the hormones involved: hypersecretion of androgens results in adrenal Virilism. Hypersecretion of glucocorticoids leads to Cushing syndrome. Hypersecretion of aldosterone, leading to hyperaldosteronism. Hypersecretion of adrenaline and noradrenaline lead to pheochromocytoma. These syndromes overlap occasionally with regard to the symptoms they cause. A gain of function can compensatory (as in congenital adrenal hyperplasia), or due to an acquired hyperplasia, adenomas or adenocarcinomas occur.


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