Overview

The endothelium lines blood vessels and regulates vascular tone permeability coagulation and inflammation. Microcirculation comprises arterioles capillaries and venules where nutrient and gas exchange occur. Endothelial health is central to vascular disease and organ perfusion.

Endothelial Function

Endothelial cells produce nitric oxide prostacyclin and other mediators to modulate vasodilation and platelet activity. They regulate leukocyte trafficking and barrier function. Dysfunction contributes to atherosclerosis thrombosis and inflammation.

Capillary Exchange

Capillary walls permit diffusion filtration and absorption governed by hydrostatic and oncotic pressures. Specialized capillaries such as fenestrated and sinusoidal types support organ specific exchange. Microvascular density influences tissue oxygenation and healing.

Clinical Relevance

Microvascular disease underlies diabetic complications ischemia and organ dysfunction. Imaging techniques such as perfusion MRI CT and nuclear studies assess microvascular flow. Therapies targeting endothelial function improve vascular outcomes.