mikroverenkierron

Mikroverenkierron, or microcirculation, refers to the part of the circulatory system that includes the smallest vessels—arterioles, capillaries, and venules—and the networks that connect them. The capillary beds provide the site of exchange between blood and interstitial fluid. The microcirculation encompasses vessels with diameters typically around 5 to 10 micrometers, including precapillary sphincters and pericyte-supported capillaries.

The primary function of mikroverenkierron is to regulate tissue perfusion and facilitate exchange of oxygen, carbon dioxide, nutrients, and waste between blood and tissues. Flow through capillary networks is governed by arteriolar tone, precapillary sphincters, and local metabolic signals. Endothelial cells release vasoactive substances such as nitric oxide and endothelin, coordinating dilation and constriction in response to tissue needs. Metabolic factors such as low oxygen, high carbon dioxide, low pH, and adenosine promote vasodilation and capillary recruitment to optimize diffusion.

Autoregulation maintains relatively stable flow across a range of arterial pressures, while neurohumoral inputs adjust regional perfusion during activity or stress. The microcirculation also supports roles in inflammation, hemostasis, and angiogenesis, contributing to tissue repair and remodeling.

Dysfunction of mikroverenkierron is linked to many diseases, including diabetes mellitus, hypertension, sepsis, and heart failure, where impaired capillary density, flow heterogeneity, or increased vascular leak can contribute to organ dysfunction. Noninvasive assessment methods include capillaroscopy, laser Doppler flowmetry, and laser speckle imaging. The microcirculation adapts to activity, with exercise increasing capillary recruitment and overall tissue perfusion, illustrating its central role in physiology and disease.