How Capillaries Move Fluid and Solutes

Capillaries move gases, nutrients, wastes, and other substances between the blood and body cells. Small molecules such as gases, lipids, and lipid-soluble substances diffuse directly through the endothelial cell membranes of the capillary wall. Glucose, amino acids, and ions such as sodium, potassium, calcium, and chloride u...

Capillary exchange refers to the movement of substances between blood and interstitial fluid.

It occurs through three mechanisms — diffusion, transcytosis, and bulk flow.

Diffusion is the most common mechanism of capillary exchange. Oxygen and nutrients, typically present at a higher concentration in blood, diffuse into the interst...