What is the Origin of Cutaneous Active Vasodilation?

This mechanism was first conceptualized and studied in the context of human exercise physiology and heat exposure, as researchers sought to explain the profound and rapid increase in skin blood flow. It was determined that the vasodilation was not merely a passive withdrawal of vasoconstrictor tone but required an active neural drive. The term specifies that the widening of vessels in the skin, or 'cutaneous' region, is 'active,' requiring energy and signaling.

What is the Mechanism of Cutaneous Active Vasodilation?

The process is initiated by sympathetic cholinergic nerves that release acetylcholine (ACh) as their primary neurotransmitter. However, the full dilation is mediated by a complex co-transmission mechanism involving ACh and one or more co-released substances, such as neuropeptides or nitric oxide (NO). These signaling molecules act directly on the smooth muscle cells of the skin's arterioles, causing them to relax and the vessels to widen, dramatically increasing the perfusion of the skin and promoting heat loss.

Cutaneous Active Vasodilation ∞ Area

Cutaneous Active Vasodilation

Meaning

Cutaneous Active Vasodilation is a highly regulated physiological process that involves the neural and chemical signaling to actively increase blood flow to the skin, primarily serving as a mechanism for thermoregulation. This active widening of skin arterioles facilitates the transfer of excess internal heat from the core of the body to the surface for dissipation. It is a key effector pathway in the maintenance of core body temperature homeostasis, preventing dangerous hyperthermia during heat stress or exercise. The response is rapid and precisely controlled by the autonomic nervous system.