Vazomotoros

Vazomotoros refers to the physiological processes and responses involving blood vessels, specifically their ability to change in diameter. This term is derived from "vaso" (vessel) and "motor" (movement), indicating the active control over blood vessel size. The primary mechanism for this control is the smooth muscle tissue present in the walls of arteries and veins. When this smooth muscle contracts, the vessel constricts, a process known as vasoconstriction. Conversely, when the smooth muscle relaxes, the vessel dilates, a process called vasodilation.

These changes in vessel diameter are crucial for regulating blood flow and blood pressure throughout the body. Vasoconstriction can increase peripheral resistance, thereby raising blood pressure, and it can also divert blood away from certain areas. Vasodilation has the opposite effect, decreasing resistance and lowering blood pressure, while also increasing blood supply to tissues.

The regulation of vazomotoros is complex and involves various factors, including the autonomic nervous system (sympathetic and parasympathetic divisions), hormones (such as adrenaline, noradrenaline, and angiotensin), and local chemical mediators (like nitric oxide and carbon dioxide). These signals can be triggered by a range of stimuli, including temperature changes, physical activity, stress, and the presence of certain substances in the bloodstream. Dysregulation of vazomotoros can contribute to a variety of medical conditions, including hypertension, Raynaud's phenomenon, and shock.