Adrenal cortex Health Dictionary

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Adrenal Cortex: From 1 Different Sources

The outer covering of the two adrenal glands that lie atop each kidney. Embryonically derived from gonad tissue, they make steroid hormones that control electrolytes, the management of fuels, the rate of anabolism, the general response to stress, and maintenance of nonspecific resistance.
Health Source: Herbal Medical
Author: Health Dictionary

Adrenal Glands

Also known as suprarenal glands, these are two small triangular ENDOCRINE GLANDS situated one upon the upper end of each kidney. (See diagram of ABDOMEN.)

Structure Each suprarenal gland has an enveloping layer of ?brous tissue. Within this, the gland shows two distinct parts: an outer, ?rm, deep-yellow cortical (see CORTEX) layer, and a central, soft, dark-brown medullary (see MEDULLA) portion. The cortical part consists of columns of cells running from the surface inwards, whilst in the medullary portion the cells are arranged irregularly and separated from one another by large capillary blood vessels.

Functions Removal of the suprarenal glands in animals is speedily followed by great muscular prostration and death within a few days. In human beings, disease of the suprarenal glands usually causes ADDISON’S DISEASE, in which the chief symptoms are increasing weakness and bronzing of the skin. The medulla of the glands produces a substance – ADRENALINE – the effects of which closely resemble those brought about by activity of the SYMPATHETIC NERVOUS SYSTEM: dilated pupils, hair standing on end, quickening and strengthening of the heartbeat, immobilisation of the gut, increased output of sugar from the liver into the bloodstream. Several hormones (called CORTICOSTEROIDS) are produced in the cortex of the gland and play a vital role in the metabolism of the body. Some (such as aldosterone) control the electrolyte balance of the body and help to maintain the blood pressure and blood volume. Others are concerned in carbohydrate metabolism, whilst others again are concerned with sex physiology. HYDROCORTISONE is the most important hormone of the adrenal cortex, controlling as it does the body’s use of carbohydrates, fats and proteins. It also helps to suppress in?ammatory reactions and has an in?uence on the immune system.... adrenal glands

Congenital Adrenal Hyperplasia

See ADRENOGENITAL SYNDROME and GENETIC DISORDERS.... congenital adrenal hyperplasia

Cortex

The tissues that form the outer part of an organ and which are positioned just below the capsule or outer membrane. Examples are the cerebal cortex of the BRAIN and the renal cortex of the KIDNEYS.... cortex

Sensory Cortex

See BRAIN.... sensory cortex

Adrenal Medulla

The inner part of the adrenals, derived embryonically from spinal nerve precursors, they secrete epinephrine, norepinephrine and dopamine; used locally as neurotransmitters, sensitive receptors can be mobilized totally by the adrenal medullas.... adrenal medulla

Adrenal-activator

An agent which stimulates the adrenal glands thereby increasing secretion of cortisol and adrenal hormones. A herb with a mild cortico-steroid effect. Liquorice. Ginseng. Sarsaparilla. ... adrenal-activator

Adrenal Failure

Insufficient production of hormones by the adrenal cortex (the outer part of the adrenal glands).

It can be acute or chronic.

Adrenal failure may be caused by a disorder of the adrenal glands, in which case it is called Addison’s disease, or by reduced stimulation of the adrenal cortex by ACTH, a hormone produced by the pituitary gland.... adrenal failure

Adrenal Gland Disorders

A range of uncommon but sometimes serious disorders due to deficient or excessive production of hormones by one or both of the adrenal glands.

A genetic defect causes congenital adrenal hyperplasia, in which the adrenal cortex is unable to make sufficient hydrocortisone and aldosterone, and androgens are produced in excess. In adrenal failure, there is also deficient production of hormones by the adrenal cortex; if due to disease of the adrenal glands, it is called Addison’s disease. Adrenal tumours are rare and generally lead to excess hormone production.

In many cases, disturbed activity of the adrenal glands is caused, not by disease of the glands themselves, but by an increase or decrease in the blood level of hormones that influence the action of the adrenal glands. For example, hydrocortisone production by the adrenal cortex is controlled by ACTH, which is secreted by the pituitary gland. Pituitary disorders can disrupt production of hydrocortisone.... adrenal gland disorders

Adrenal Tumours

Cancerous or noncancerous tumours in the adrenal glands, usually causing excess secretion of hormones. Adrenal tumours are rare. Tumours of the adrenal cortex may secrete aldosterone, causing primary aldosteronism, or hydrocortisone, causing Cushing’s syndrome. Tumours of the medulla may cause excess secretion of adrenaline and noradrenaline. Two types of tumour affect the medulla: phaeochromocytoma and neuroblastoma, which affects children. These tumours cause intermittent hypertension and sweating attacks. Surgical removal of a tumour usually cures these conditions.... adrenal tumours

Motor Cortex

the region of the *cerebral cortex that is responsible for initiating nerve impulses that bring about voluntary activity in the muscles of the body. It is possible to map out the cortex to show which of its areas is responsible for which particular part of the body. The motor cortex of the left cerebral hemisphere is responsible for muscular activity in the right side of the body.... motor cortex

Adrenal Hyperplasia, Congenital

An uncommon genetic disorder in which an enzyme defect blocks the production of corticosteroid hormones from the adrenal glands. Excessive amounts of androgens (male sex hormones) are produced, which can result in abnormal genital development in an affected fetus. Other effects include dehydration, weight loss, low blood pressure, and hypoglycaemia. Hyperplasia (enlargement) of the adrenal glands occurs and there is excessive skin pigmentation in skin creases and around the nipples.

In severe cases, the disorder is apparent soon after birth. In milder cases, symptoms appear later, sometimes producing premature puberty in boys and delayed menstruation, hirsutism, and potential infertility in girls.

Congenital adrenal hyperplasia is confirmed by measuring corticosteroid hormones in blood and urine. Treatment is by hormone replacement. If this is started early, normal sexual development and fertility usually follow.... adrenal hyperplasia, congenital

Cerebral Cortex

the intricately folded outer layer of the *cerebrum, making up some 40% of the brain by weight and composed of an estimated 15 thousand million neurons (see grey matter). This is the part of the brain most directly responsible for consciousness, with essential roles in perception, memory, thought, mental ability, and intellect, and it is responsible for initiating voluntary activity. It has connections, direct or indirect, with all parts of the body. The folding of the cortex provides a large surface area, the greater part lying in the clefts (sulci), which divide the upraised convolutions (gyri). On the basis of its microscopic appearance in section, the cortex is mapped into *Brodmann areas; it is also divided into functional regions; including *motor cortex, *sensory cortex, and *association areas. Within, and continuous with it, lies the *white matter, through which connection is made with the rest of the nervous system.... cerebral cortex

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