Vasomotor

Vasomotor reactions are changes in the diameter of blood vessels and the lumen of the trachea and bronchi that occur in response to changes in environmental conditions and physiological factors. These reactions can be both positive and negative, and they play an important role in regulating blood circulation and respiration.

Vasomotor reactions occur due to the action of vasomotor nerve fibers that innervate blood vessels and bronchial muscles. These fibers transmit information about the state of the body and the environment to the brain, where this information is processed and commands for the vasomotor response are generated.

A positive vasomotor response occurs when the body's need for oxygen or nutrients increases. This may be due to exercise, stress, hunger or thirst. In this case, the blood vessels dilate, increasing blood flow to the organs, which provides them with oxygen and nutrients.

A negative vasomotor response occurs when the body lacks oxygen or nutrients. This can happen, for example, with hypoxia (lack of oxygen) or insufficient nutrition. In this case, the blood vessels narrow, reducing blood flow to the tissues, which helps conserve oxygen and nutrients for important organs.

In addition, vasomotor reactions can occur in response to various physical factors, such as ambient temperature, pressure, humidity, etc. For example, as ambient temperatures rise, blood vessels may dilate to increase blood flow to the skin and cool the body.

In general, vasomotor reactions play an important role in maintaining homeostasis (constancy of the internal environment) of the body. They provide adequate perfusion (blood supply) to tissues and organs, which is necessary for their normal function and the survival of the body.