Gefäßwandregelung

Gefäßwandregelung refers to the active and complex mechanisms by which the walls of blood vessels, particularly arteries and veins, adjust their diameter and tone. This regulation is crucial for maintaining blood pressure, controlling blood flow to different tissues, and ensuring adequate oxygen and nutrient delivery. The primary effector cells in this process are the smooth muscle cells within the tunica media of the vessel wall. These cells can contract or relax in response to various stimuli, leading to vasoconstriction (narrowing of the vessel) or vasodilation (widening of the vessel).

Key regulators of gefäßwandregelung include the autonomic nervous system, hormones, and local factors. The sympathetic nervous system, through the release of norepinephrine, generally causes vasoconstriction, increasing blood pressure. Conversely, parasympathetic stimulation can lead to vasodilation, though its role in vascular tone is less prominent than sympathetic influence. Hormones such as angiotensin II are potent vasoconstrictors, while atrial natriuretic peptide promotes vasodilation. Local factors also play a significant role. Endothelial cells, the inner lining of blood vessels, produce substances like nitric oxide (NO), a powerful vasodilator, and endothelin-1, a vasoconstrictor. Metabolic byproducts, such as adenosine and lactic acid, released during increased tissue activity, also contribute to local vasodilation, ensuring blood supply matches demand. This intricate interplay of neural, hormonal, and local signals allows for precise control of blood flow throughout the circulatory system.