smallbloodvessel
Small blood vessels, collectively the microvasculature, include arterioles, capillaries, and venules with diameters typically under 100 micrometers. They connect larger arteries and veins and are specialized for tissue perfusion and exchange. Capillaries, about 5–10 micrometers in diameter, are the principal sites of gas and nutrient exchange; arterioles regulate flow and pressure; postcapillary venules drain the capillary beds.
Anatomy: the vessels are lined by endothelial cells on a basement membrane. Capillaries may be continuous, fenestrated,
Function: exchange of oxygen, carbon dioxide, nutrients and wastes, maintenance of interstitial fluid balance, and leukocyte
Regulation and adaptation: local mediators such as nitric oxide and endothelin, along with metabolic cues, regulate
Clinical relevance: microvascular dysfunction is implicated in diabetic microangiopathy, hypertension-related small vessel disease, and cerebral or