Baroreceptor

In the human body register baroreceptors ( Drucksinneskörperchen, also called pressoreceptors ) the pressure of the flowing arterial blood to the vessel walls. Mechanoreceptors as they are activated by stretching the vessel wall. The measure of their activity - that is, the frequency of the transmitted signals - depending on the degree of vessel wall strain.

Your impulses reach the medulla oblongata, a partial structure of the central nervous system (CNS). There they cause inhibition ( inhibition) of neurons, whose task is to increase the heart rate (the number of heart beats per minute). Therefore Active baroreceptors prevent an increase in the pulse rate.

Baroreceptors are located mainly in the vessel walls ( adventitia and media ) of the aorta but also in most other arteries. Your task is to keep the arterial blood pressure at a constant level and thus to ensure the demand- blood supply of the individual organs. If, for example, the blood pressure ( for example in hypovolemic shock ), the elongation of the aortic wall decreases and decreases the activity of baroreceptors. As a result, decreases the frequency of their signals to the medulla oblongata. The neurons of the medulla oblongata send now, after the elimination of baroreceptor -mediated inhibition signals to the heart muscle, the pacemaker and various veins and arteries of the body. Baroreceptors are constantly active: Even at constant pressures in the physiological range cycle -regulating neurons are constantly fed impulses.

In response to these signals to accelerate the heart rate. This increases the amount of material dispensed from the heart blood. The term of the baroreceptors is about a second, so in a spontaneous pressure drop already the next cardiac interval can be shortened. The arterioles and veins constrict, it flows less blood to non- vital organs. These two reactions of the blood pressure returns to the arteries quickly back to normal. The redistribution of the blood is done via a release of adrenaline and is mainly mediated by β - receptors. But other catecholamines such as norepinephrine are released at low blood pressure and have a vasoconstrictor effect.

But baroreceptors register not only a change in pressure, but also " how fast " it expires, ie the rate of change.

Baroreceptors are also the controversial phenomenon of changes in the weather condition.