Adrenal cortex physiology

Dehydroepiandrostemne (DHEA) and dehydroepiandrosterone sulfate (DHEAS) are the most abundant steroids secreted by the adrenal cortex under pituitary ACTH control (B5). Very little plasma DHEA(S) appears to be of testicular or ovarian origin. Physiologically, the concentration of DHEA(S) in the blood oscillates coincidentally with cortisol, consistent with the response of adrenal... 

Steroid hormones are produced by the adrenal cortex, testes, ovaries, and placenta. Synthesized from cholesterol, these hormones are lipid soluble therefore, they cross cell membranes readily and bind to receptors found intracellularly. However, because their lipid solubility renders them insoluble in blood, these hormones are transported in the blood bound to proteins. Furthermore, steroid hormones are not typically preformed and stored for future use within the endocrine gland. Because they are lipid soluble, they could diffuse out of the cells and physiological regulation of their release would not be possible. Finally, steroid hormones are absorbed easily by the gastrointestinal tract and therefore may be administered orally. 

The steroid hormones known as mineralocorticoids and glucocorticoids are synthesized in the adrenal cortex of mammals [3]. The physiological mineralocorticoid is... 

The tenn corticosteroids refers to steroid hormones secreted by the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior. 

A. Angiotensin II has diverse physiological effects, including stimulating the synthesis and release of aldosterone from the adrenal cortex. This effect of angiotensin II results in fluid and water retention. The other answers are incorrect in that angiotensin II... 

Another major function of the adrenal cortex is the regulation of water and electrolyte metabolism. The principal mineralocorticoid, aldosterone, can increase the rate of sodium reabsorption and potassium excretion severalfold. This will occur physiologically in response to sodium or volume depletion or both. The primary site of... 

A partial list of physiological functions til at have been determined to be affected by vitamin C deficiencies includes (1) absorption of iron (2) cold tolerance, maintenance of adrenal cortex (3) antioxidant (4) metabolism of tryptophan, phenylalanine, and tyrosine (5) body growth (6) wound healing (7) synthesis of polysaccharides and collagen (8) formation of cartilage, dentine, bone, and teeth and (9) maintenance of capillaries. 

The principal physiological functions of tins vitamin include growth, production of visual purple, maintenance of skin and epithelial cells, resistance to infection, gluconeogenesis. mucopolysaccharide synthesis, bone development, maintenance of myelin and membranes, maintenance of color and peripheral vision, maintenance of adrenal cortex and steroid hormone synthesis, Specific vitamin A deficiency diseases include xerophthalmia, nyctalopia, hemeralopia, keratomalacia, and hyperkeratosis. 

Steroid hormones are biosynthesized from cholesterol in the adrenal cortex, gonads, and placenta. These steroids are important hormones for many specific physiological processes. 

The primary glucocorticoid released in humans is cortisol (also known as hydrocortisone). Cortisol synthesis and secretion are under the control of specific hypothalamic and pituitary hormones.7,24 31 Corticotropinreleasing hormone (CRH) from the hypothalamus stimulates the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary. ACTH travels in the systemic circulation to reach the adrenal cortex, where it stimulates cortisol synthesis. Cortisol then travels in the bloodstream to various target tissues to exert a number of physiologic effects (see Physiologic Effects of Glucocorticoids, later). 

Male and female hormones are produced primarily in the gonads. Androgens are synthesized in the testes in the male. In the female, the ovaries are the principal sites of estrogen and progestin production. As discussed in Chapter 29, small amounts of sex-related hormones are also produced in the adrenal cortex in both sexes, which accounts for the fact that small amounts of hormones of the opposite sex are seen in females and males that is, low testosterone levels are seen in females, and males produce small quantities of estrogen. However, under normal conditions, the amounts of sex-related hormones produced by the adrenal cortex are usually too small to produce significant physiologic effects. 

Some of the most important physiological steroids are the adrenocortical hormones, synthesized by the adrenal cortex. Most of these hormones have either a carbonyl group or a hydroxyl group at Cl 1 of the steroid skeleton. The principal adrenocortical hormone is cortisol, used for the treatment of inflammatory diseases of the skin (psoriasis), the joints (rheumatoid arthritis), and the lungs (asthma). Figure 25-10 compares the structure of natural cortisol with two synthetic corticoids fluocinolone acetonide, a fluori-nated synthetic hormone that is more potent than cortisol for treating skin inflammation and beclomethasone, a chlorinated synthetic hormone that is more potent than cortisol for treating asthma. 

Animals ex adrenal cortex (ACTH-induced) Tadeusz Reichstein (Poland/Switzerland) Edward Kendall Philip Hench (USA) (Nobel Prize, Physiology/Medicine, 1950, glucocorticoids)... 

The pituitary output of corticotropin responds rapidly to physiological requirements by the familiar negative-feedback homeostatic mechanism. Since the of corticotropin is 10 min and the adrenal cortex responds rapidly (within 2 min) it is plain that adjustments of steroid output can be quickly made. 

Cortisol and aldosterone produced rn the adrenal cortex have a major role in physiology and pharmacology. 

Vasopressin has a direct effect on the adrenal cortex at pharmacological doses, but it does not cause the release of ACTH at physiological concentrations. 

Corticosteroids are hormones produced in the adrenal cortex and regulate inflammation, electrolyte levels, stress response, carbohydrate metabolism, and other physiological responses. Corticosteroids are typically prescribed for short-term treatment of inflammation. 

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