Adrenals are paired glands of the internalsecretion. They are located above the upper parts of the kidneys in the region of 11-12 thoracic vertebrae. The function of the adrenal glands in the human body is the production and release into the blood of a number of important hormones necessary to maintain normal vital activity.
The structure of the adrenal glands
The left adrenal gland in an adult hassemilunar form, right triangular. Both adrenal glands are enclosed in a fine fibrous capsule. In length they reach 7 cm, width - 3.5 cm. The thickness reaches 8 mm. Their mass on the average is about 14 g. From the adrenal glands bundles of connective tissue with nerves and blood vessels depart. Blood enters the three groups of arteries, and its outflow occurs through the central and superficial veins. In the organ itself, 2 parts are isolated. The outer part consists of a cortex and accounts for 90% of the total weight of the adrenal glands. Cortex, in turn, is divided into 3 zones: glomerular, bundle, reticulate. It realizes the functions of the adrenal glands for the production of steroid, corticosteroid and sex hormones. Inside the body is filled with a brain substance and contains a lot of nerve cells. The basis of the same substance is chromaffin cells. These cells provide the function of the adrenal glands to produce catecholamine hormones: dopamine, norepinephrine and adrenaline.
The adrenal glands secrete a number of hormones regulatingexchange processes. For example, glucocorticoid hormones contribute to carbohydrate metabolism in the body. With their overabundance, diabetes can develop. Also the decomposition of adipose tissue is regulated. Hormones, produced by the adrenal glands, control the amount and location of its deposits.
Functions of adrenal glands in regulation of water-salt balance
Thanks to these glands, thethe retention of water in the body and the exercise of mineral metabolism. This process is closely related to the work of the kidneys and the substances that are synthesized in them. Any violations in this system are fraught with the accumulation of excess fluid, increased blood pressure, as well as kidney damage.
Adrenal function in the production of sex hormones
In the cortex of the paired glands are formedandrogens and estrogens - male and female sex hormones. They affect reproductive function, and also are important for the formation of secondary sexual characteristics. For example, androgens affect hair growth and support the function of the sebaceous glands in the body.
Functions of adrenal glands in the adaptation of the organism to stress conditions
These functions are to developspecial neurotransmitters (adrenaline, norepinephrine), which affect the work of the sympathetic nervous system, participating in the conduct of impulses. Thus, these hormones contribute to the restructuring of the body in a state of stress. They increase the pulse and blood pressure, increase sweating, reduce the motility of the gastrointestinal tract, stimulate the expansion of the bronchi.