The endocrine system, working in conjunction with the nervous system, ensures the adaptation of the body to environmental conditions.
The nervous system transmits its effect to the organs very quickly and accurately, since nerve impulses travel at high speed along the nerve fibers to specific organs.
The endocrine system acts much more slowly. Its influence does not have a specific address, since hormones are carried by the blood throughout the body.
Humoral regulation of the body ensures the relationship between organs, maintaining the constancy of the internal environment, adaptation to external conditions. Hormones play a major role in the humoral regulation of body functions. They affect the growth, reproduction, and differentiation of tissues.
The highest center for the regulation of endocrine functions (regulation of the activity of the endocrine glands) is the hypothalamus – a section of the diencephalon. It is he who unites the nervous and humoral regulation in the neurohumoral mechanism of regulation of the body’s vital activity.
An example of the interaction of the nervous and humoral regulation of the functions of the endocrine glands can be the hypothalamic-pituitary system, which is formed by a part of the brain – the hypothalamus – and the endocrine gland – the pituitary gland (maintaining a constant level of hormones in human blood is associated with the hypothalamic-pituitary system).
The neurosecretory cells of the hypothalamus respond to impulses coming to them like ordinary nerve cells, but when excited they form hormones that affect the work of the pituitary gland.
The neurohormones of the hypothalamus enter the pituitary gland through the funnel and pedicle. Under the influence of these substances, the pituitary gland produces its hormones, which have a regulatory effect on all endocrine glands.
The hypothalamus and pituitary gland are linked into a single system and work in concert. Thus, through the hypothalamus, the nervous system can enhance or inhibit the secretory activity of the endocrine glands.