Nervous-humoral system. Regulation of breathing and its features.
In the human body, all life processes are regulated. Nature has two mechanisms, which are used for this purpose - nervous and humoral. It is with their help that the regulation of breathing occurs.
Breathing is a vital process in our body. The respiratory system ensures the exchange of CO2 and O2 between the body and the external environment. This important life function is regulated by numerous neurons of the central nervous system, which are located in several parts of the brain and are united in the generalized concept of "respiratory center".It is affected by nervous and humoral stimuli, while adapting the function of breathing itself to the conditions of the external environment, which are constantly changing.
Nervous breathing regulation
Structures that are simply necessary for the onset of respiratory rhythms were first found in the medulla oblongata. Its destruction leads to a cessation of breathing. The cerebral cortex takes a direct part in the regulation of respiration. That is why the respiratory center is in constant activity. In it rhythmic impulses of excitation arise and rhythmic activity is recorded. Further, pulses from the center are transmitted to the respiratory muscles and the diaphragm by means of centrifugal neurons. In this way the exhalation and inspiration alternate in our body. With pain stimulation, irritation of the receptors of blood vessels or irritation of organs located in the abdominal cavity, the change in breathing takes place completely reflexively.
So, if you inhale pairs of ammonia, the receptors of the nasopharyngeal mucosa will be irritated, this can lead to a reflex delay in the respiratory process. This is the body's defense, which works to prevent harmful gases from entering the lungs. The regulation of breathing occurs when nerve impulses from the respiratory muscles and receptors located in the lungs themselves. The depth of exhalation and inspiration depends on these impulses.
The regulation of breathing also contributes to the adaptation of the body to environmental changes, for example, holding the breath, a person can independently change its rhythm and depth. In athletes, it is the influence of the cerebral cortex that explains the pre-start changes in breathing, its acceleration and deepening before the start of the competition.
Humoral regulation of respiration.
The respiratory center is affected by the chemical composition of the blood, namely, its gas composition. Accumulating in the blood, carbon dioxide irritates the receptors in the blood vessels that carry blood to the head, and stimulates the respiratory center on the basis of reflexes. Other products with high acidity, which enter the blood, for example lactic acid, also act. Its content increases in the blood during muscular work. This response of the respiratory center to a change in the state of the organism due to the influence of the external environment occurs instantaneously, in a matter of a fraction of a second. Perhaps, in this way our body worries about the state of our health and warns about the future or forthcoming danger. Humoral regulation can rightfully be called the oldest form of interaction between our organs and cells.
Also many necessary functions in our body are regulated by hormones. These are highly active and so essential to the body substances that are produced by glands of internal secretion. The secretory cells gland with their surface come into contact with the walls of the blood vessels. That's why hormones quickly penetrate into the blood. Their action on the body is significant.
As we see, both nervous and humoral regulation are of great importance for the whole organism, and not only for the respiratory system.