The adrenal glands are a paired vital internal secretion organ. They are located above the upper poles of the kidneys at the level between the I lumbar and XI thoracic vertebra. The right adrenal gland is bordered by the inferior vena cava and liver, and the left adrenal gland, located slightly higher than the right, with the pancreas and splenic vessels. The shape of the right adrenal gland resembles a pyramid, and the left, somewhat larger, crescent.

The mass of both adrenal glands varies from 6 to 12 g. The length of the adrenal glands reaches 40–60 mm, the width is 20–35 mm, and the thickness is 6–10 mm. Outside, the adrenal glands are surrounded by a connective tissue capsule, to the inner layers of which the subcapsular layer is adjacent. The latter is a regenerative layer of the adrenal cortex. From the connective tissue capsule into the deeper layers of the adrenal gland, the strands that divide the gland into zones are given.

The adrenal gland consists of an outer cortical substance having a yellow color and an internal cerebral substance of a reddish-brownish tinge (Fig. 52). In turn, the cortex of the Chadposti gland consists of three zones: the outer glomerular zone (zona glomerulosa), which is located above the subcapsular layer, of the beam zone (zona fasciculata), which occupies a median position, and the net zone (zona reticularis), which is in direct contact with the medulla. The glomerular zone is the narrowest. It consists of polygonal or irregular cubic cells forming glomeruli. The beam zone is the widest. It is formed by large glandular cells of a cubic, polygonal shape, but most often cells in the form of prisms. The weights of these cells are located in the form of beams going from the glomerular to the reticular zone. The beam cells are rich in cholesterol, ascorbic acid and lipids. The mesh zone consists of smaller glandular cells located in the form of an irregular loose network.

The adrenal medulla has a loose structure and is about 1/10 of the cortex. The brain substance consists of chromaffin (pheochromic) cells having a polygonal, prismatic or round shape, as well as sympathetic ganglion cells. The chromaffin cells are located in the form of cords or groups. When chromaffin cells are stained with salts of chromic acid, they become brown in color, as a result of which they are also called pheochromic cells. The blood supply to the adrenal glands is at the expense of the superior, middle, and inferior adrenal arteries. The first two depart from the abdominal aorta, the last is a branch of the renal artery.

It should be noted that both the cortical and the medulla above the kidney usually have isolated vascular systems. Blood enters the brain substance of the adrenal gland through special arteries. Passing through the adrenal cortex without branching, these arteries are scattered into the capillaries between clusters and strands of medulla cells. The venous blood of the adrenal glands is collected first into the sinuses and sinusoids, and then into the small outflow veins, which in turn form the central vein of the adrenal gland. The right adrenal vein flows into the inferior vena cava, and the left into the left renal vein. Part of the blood from the adrenal medulla, having passed through special veins through the cortical substance, enters the veins of the portal system outside the adrenal gland. The innervation of the adrenal glands is due to the fibers of the sympathetic and parasympathetic nerves, originating mainly from the celiac nerves and further from the solar and adrenal plexuses.

50 steroid compounds are currently isolated from the adrenal cortex. Their chemical structure is based on a steroid ring of 17 carbon atoms (cyclopentan tanoperhydrophenanthrene core), and therefore they are called corticosteroids. Found 8 biologically active drugs of steroids, but the true hormones are cortisol.
(hydrocortisone), corticosterone, aldosterone, and others. True hormones account for 80% of all corticosteroids produced. The formation of aldosterone occurs in the glomerular zone of the adrenal cortex, cortisol, and corticosterone — mainly in the puchkovy zone, and of the sex hormones (testosterone, estradiol) in the net zone. Corticosterone, the precursor of aldosterone, is partially synthesized also in the glomerular zone. According to some authors, the biosynthesis of cortisol, corticosterone, and sex hormones can occur both in the puchal and in the reticular zone. Depending on the predominant physiological effect, in addition to sex hormones, glucocorticoid (cortisol, corticosterone) and mineralocorticoid (aldo steron) are secreted. The most active glucocorticoid is a cortex of ashes.

Along with glucocorticoid properties, corticosterone has pronounced mineralocorticoid signs. Kortizol is involved in the regulation of carbohydrate, protein and lipid metabolism. It enhances glyconeogenesis from protein and fat, contributes to the deposition of glycogen in the liver, participates in the transport of glucose to muscles, adaptation (adaptation) of the body to the action of stress factors (infection, intoxication, grass, etc.).

local_offerevent_note February 23, 2019

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