Gefäßkonstriktion

Gefäßkonstriktion refers to the narrowing of blood vessels. This physiological process is crucial for regulating blood flow and blood pressure within the body. When blood vessels constrict, their inner diameter decreases, which increases resistance to blood flow and consequently raises blood pressure. This mechanism is primarily controlled by the autonomic nervous system, specifically the sympathetic nervous system, through the release of neurotransmitters like norepinephrine. Hormones such as angiotensin II and vasopressin also play significant roles in inducing vasoconstriction.

Several factors can trigger gefäßkonstriktion. In situations of stress or danger, the "fight-or-flight" response leads to sympathetic activation, causing blood vessels to narrow, redirecting blood to essential organs like the heart and brain. Cold temperatures also induce vasoconstriction to conserve body heat by reducing blood flow to the skin's surface. Conversely, certain medical conditions can lead to inappropriate or excessive gefäßkonstriktion, contributing to problems like hypertension, ischemia, and Raynaud's phenomenon. The reversal of gefäßkonstriktion is known as gefäßdilatation, the widening of blood vessels.