Adrenal glands

Adrenal glands (epinephral, adrenal glands) – the pair closed glands located over kidneys.

Structure and functions of adrenal glands

The structure of glands emits outside cortical substance and internal brain. They have a different origin, but in the course of historical development combined in one body. Adrenal glands have the different form – right triangular, and left semi-lunar. Outside of gland are covered with the capsule which gives shoots inside.

Cortical substance prevails, and makes about 9/10 from the mass of glands. It consists of the cells cosecreting corticosteroid and sex hormones. Cells are located rather circulatory capillaries so that the secret came to blood at once. In cortical substance of adrenal glands allocate three zones differing on cellular structure:

• Glomerular (develops Aldosteronum);
• Puchkovy (develops cortisol, corticosterone);
• Mesh (synthesizes androgens).

It is difficult to revaluate a role of corticosteroid hormones in an organism. They participate in the key moments of regulation of a metabolism (proteins, fats, carbohydrates, water and salts), energy, in a host defense of an organism, regulation of a tone of vessels, adaptation to stresses.

Marrow in the center of an adrenal gland is unsharply delimited from cortical, and consists of chromaffin cells, and also a set of nerve fibrils and cells. Secretory chromaffin cells synthesize adrenaline, dopamine and noradrenaline. On a chemical structure they concern group of catecholamines, and are initially formed of tyrosine amino acid. Emission of catecholamines in blood is stimulated with various irritants – emotions, a hypoglycemia, overcooling, physical activity, etc.

Adrenaline increases in blood glucose level due to disintegration of a glycogen, strengthens disintegration of fats with energy release, increases arterial pressure, strengthens the frequency and force of cordial reductions, weakens unstriated muscles in walls of bronchial tubes, strengthens formation of heat in an organism.

Noradrenaline – the predecessor of adrenaline, has a bit different effects – it urezhat cordial reductions, expands the arteries feeding with blood heart, increases diastolic pressure.

Research of functions of adrenal glands

It is impossible to probe adrenal glands at a palpatorny research. Ultrasonography allows to visualize them and to determine the sizes.

Function them is studied, investigating the level of hormones and their metabolites in blood. So that to estimate glucocorticoid function of adrenal glands, in blood determine the level 11 of oxycorticosteroids, and in urine – free cortisol.

Functional trials allow to estimate the response of adrenal glands to stimulation from the outside. Most often apply test with dexamethasone which helps to otdifferentsirovat a tumor of adrenal glands from the hyperplasia connected with excess synthesis of AKTG in a hypophysis. Test with AKTG allows to reveal functional insufficiency of adrenal glands, but in view of potential health hazard such tests should be carried out in a hospital.

Mineralokortikoidny function of adrenal glands and formation of hormone of Aldosteronum can be estimated on the maintenance of potassium ions and sodium in blood serum. At insufficiency of adrenal glands the content of sodium is considerably reduced, and potassium is increased, at excess formation of Aldosteronum of potassium on the contrary will be less, and it is more sodium.

Radiological methods of inspection of adrenal glands – a computer and magnetic and resonant tomography, an angiography. They allow to reveal tumors of adrenal glands, to estimate the sizes and structure of glands.

Diseases and approaches to treatment of adrenal glands

All diseases of adrenal glands can be divided into two big groups – one of them is shown by excess function of adrenal glands, and the second – on the contrary, reduced.

Decrease in work of glands happens during removal of adrenal glands, defeat by their tuberculosis, an amyloidosis, a sarcoidosis, at hemorrhage in adrenal glands or at decrease in formation of AKTG in a hypophysis. Treatment of adrenal glands in this case demands replacement therapy by those hormones which lack was created, and also elimination of the reason of hypofunction.

Excess formation of hormones meets at a hyperplasia from excess stimulation of AKTG (for example, at a hypophysis tumor) or at an adrenal gland tumor. Tumors from cortical substance – kortikosteroma – are more often mixed, at them there is an excess formation of all adrenal hormones. If the tumor comes from the cells forming androgens it call an androsteroma. The virilny syndrome will be its manifestation. If the cells forming Aldosteronum underwent tumoral transformation, then the aldosteroma forms, and the expressed disturbances of exchange of water and salts will become its manifestation.

At Itsenko-Cushing's disease sensitivity of a hypothalamus to the inhibiting influence of cortisol is broken, as a result adrenal glands strenuously develop it and hypertrophy. At such patients carbohydrate metabolism is broken, sexual function is reduced. Outward – adiposities in a stomach, a trunk and a neck, red-violet extensions on skin – striya, a crescent-shaped face, excess pilosis is characteristic. Treatment of an Icenco-Cushing syndrome consists adrenal glands and lifelong replacement hormonal therapy at a distance.

At high-quality regeneration of cells of marrow of adrenal glands the course of a tumor asymptomatic, and it becomes more often an accidental find at a research. Malignant hormonal and active tumors are shown by symptoms of hyperproduction of hormones, hormonal and inactive the general intoxication and increase in a stomach accompanies.

Treatment of adrenal glands at tumoral defeat surgical, at malignant tumors has to be followed by chemotherapy. After removal of adrenal glands lifelong replacement therapy is required by hormones.

Inborn dysfunction of bark of adrenal glands, Itsenko-Cushing's disease, hypoaldosteronism, hromaffinoma, addisonova a disease occur at children. Quite often they have a hemorrhage in adrenal glands, for example, at a severe birth trauma, serious infections (a spotted fever, etc.).