The human body bases its work on the well-coordinated interaction of a large number of cells, tissues and organs with different structures and functional purposes. To implement this interaction, in the course of the evolution of living organisms, a number of biological mechanisms were 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 the 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, the endocrine glands release corticosteroid hormones into the bloodstream. The level of these hormones serves as a signal landmark for neurons and stimulates the endocrine system. Hormones penetrate to the cells through the intercellular space or through the blood vessels. Cells that are sensitive to the effects of hormones have specialreceptors. These receptors are able to perceive even a small amount of a hormonal substance and, upon contact with it, cause intracellular changes.
Organs of the 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, pancreas, sex, thyroid and parathyroid glands. The diffuse part is formed by individual endocrine cells located in various tissues of the whole organism.
Main functions of the endocrine system
Hormones released into the blood perform the following functions:
- Participation in the biochemical reactions of the body.
- Coordination of the joint activities of the internal organs of a person.
- Influence on the growth of the body and ensuring the development of all its systems. For example, promoting calcium absorption and skeletal growth.
- Gender differentiation and reproductive function. The gonads and adrenal cortex, which are also part of the endocrine system, secrete substances that ensure the formation of primary and secondary sexual characteristics.
- Adjusting the body to environmental changes. An example would besubstances of the catecholamine group, such as adrenaline. They are able to influence the rhythm of heart contractions, sweating, bronchial dilation.
- Influence on the psycho-emotional state and behavioral aspects of human activity. For example, glucocorticoid hormones can cause euphoria in a person, but their overabundance leads to serious stress.
