Mineralocorticoid in the context of "Adrenal glands"

Progestogens, also sometimes written progestins, progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. The progestogens are named for their function in maintaining pregnancy (i.e., progestational), although they are also present at other phases of the estrous and menstrual cycles.

The progestogens are one of three types of sex hormones, the others being estrogens like estradiol and androgens/anabolic steroids like testosterone. In addition, they are one of the five major classes of steroid hormones, the others being the androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as the neurosteroids. All endogenous progestogens are characterized by their basic 21-carbon skeleton, called a pregnane skeleton (C21). In similar manner, the estrogens possess an estrane skeleton (C18), and androgens, an androstane skeleton (C19).

A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence cortico-) and sex steroids (typically made in the gonads or placenta). Within those two classes are five types according to the receptors to which they bind: glucocorticoids and mineralocorticoids (both corticosteroids) and androgens, estrogens, and progestogens (sex steroids). Vitamin D derivatives are a sixth closely related hormone system with homologous receptors. They have some of the characteristics of true steroids as receptor ligands.

Steroid hormones help control metabolism, inflammation, immune functions, salt and water balance, development of sexual characteristics, and the ability to withstand injury and illness. The term steroid describes both hormones produced by the body and artificially produced medications that duplicate the action for the naturally occurring steroids.

Dexamethasone is a fluorinated glucocorticoid medication used to treat rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive pulmonary disease (COPD), croup, brain swelling, eye pain following eye surgery, superior vena cava syndrome (a complication of some forms of cancer), and along with antibiotics in tuberculosis. In adrenocortical insufficiency, it may be used in combination with a mineralocorticoid medication such as fludrocortisone. In preterm labor, it may be used to improve outcomes in the baby. It may be given by mouth, as an injection into a muscle, as an injection into a vein, as a topical cream or ointment for the skin or as a topical ophthalmic solution to the eye. The effects of dexamethasone are frequently seen within a day and last for about three days.

The long-term use of dexamethasone may result in thrush, bone loss, cataracts, easy bruising, or muscle weakness. It is in pregnancy category C in the United States, meaning that it should only be used when the benefits are predicted to be greater than the risks. In Australia, the oral use is category A, meaning it has been frequently used in pregnancy and not been found to cause problems to the baby. It should not be taken when breastfeeding. Dexamethasone has anti-inflammatory and immunosuppressant effects.

The zona glomerulosa (sometimes, glomerular zone) of the adrenal gland is the most superficial layer of the adrenal cortex, lying directly beneath the renal capsule. Its cells are ovoid and arranged in clusters or arches (glomus is Latin for "ball").

In response to increased potassium levels, renin or decreased blood flow to the kidneys, cells of the zona glomerulosa produce and secrete the mineralocorticoid aldosterone into the blood as part of the renin–angiotensin system. Although sustained production of aldosterone requires persistent calcium entry through low-voltage activated Ca channels, isolated zona glomerulosa cells are considered nonexcitable, with recorded membrane voltages that are too hyperpolarized to permit Ca channels entry. However, mouse zona glomerulosa cells within adrenal slices spontaneously generate membrane potential oscillations of low periodicity; this innate electrical excitability of these cells provides a platform for the production of a recurrent Ca channels signal that can be controlled by angiotensin II and extracellular potassium, the 2 major regulators of aldosterone production. Aldosterone regulates the body's concentration of electrolytes, primarily sodium and potassium, by acting on the distal convoluted tubule of kidney nephrons to: increase sodium reabsorption, increase potassium excretion, increase water reabsorption through osmosis.

Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involved in a wide range of physiological processes, including stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior.

Some common naturally occurring steroid hormones are cortisol (C
₂₁H
₃₀O
₅), corticosterone (C
₂₁H
₃₀O
₄), cortisone (C
₂₁H
₂₈O
₅) and aldosterone (C
₂₁H
₂₈O
₅) (cortisone and aldosterone are isomers). The main corticosteroids produced by the adrenal cortex are cortisol and aldosterone.