The human body bases its work on the harmonious interaction of a large number of cells, tissues and organs having a different structure and functional purpose. To carry out this interaction during the evolution of living organisms, a number of biological mechanisms have been created that control the activity of internal organs and ensure the adaptation of their work to changing external and internal conditions. These mechanisms include the human endocrine system .
The action of the endocrine system
The action of endocrine organs is based on the production of special active substances - hormones. It has a close relationship with the functioning of the nervous system of the body. The hypothalamus produces corticoliberin, which stimulates the pituitary gland to secrete corticotropin. In response to this, the endocrine glands release hormones corticosteroids into the blood . The level of these hormones serves as a signal reference for neurons and stimulates the endocrine system. Hormones penetrate the cells through the intercellular space or through the blood vessels. Cells that are sensitive to hormones have special receptors on their surface. These receptors are able to perceive even a small amount of a hormonal substance and, upon contact with it, cause intracellular changes.
Human endocrine system
There are several organs responsible for the production of hormones. In addition, in many tissues of the body there are special cells that secrete hormonal substances. In this regard, the endocrine system is usually divided into two parts: glandular and diffuse. The first part includes the endocrine glands. For example, glands such as the adrenal glands, pancreas, genital, thyroid, and parathyroid glands. The diffuse part is formed by individual endocrine cells located in various tissues of the whole organism.
The main functions of the endocrine system
The hormones secreted into the blood carry out the following functions:
- Participation in biochemical reactions of the body.
- Coordination of the joint activities of internal organs
- Influence on the growth of the body and ensuring the development of all its systems. For example, promoting calcium absorption and skeletal bone growth.
- Sexual distinction and ensuring reproductive function. Sexual glands and adrenal cortex, which also enter the endocrine system, secrete substances that ensure the formation of primary and secondary sexual characteristics.
- Body tuning to environmental changes. Examples are catecholamine group substances such as adrenaline. They are able to influence the rhythm of heart contractions, sweating, expansion of the bronchi.
- Influence on the psychoemotional state and behavioral aspects of human activity. For example, hormones glucocorticoids can cause euphoria in a person, but their excess leads to serious stress.