Continuous Capillary EM
Continuous Capillary EM

Continuous Capillary EM

Endothelial cells in continuous capillaries completely enclose the lumen of the blood vessel. The only gaps are the junctions between adjacent endothelial cells where small molecules can diffuse between the bloodstream and surrounding tissue. Continuous capillaries are prominent in adipose and muscle tissue and in the brain. Which protein primarily determines the rate of paracellular diffusion in endothelial cells? Which protein mediates adhesion between endothelial cells?
Answer: Tight junctions regulate paracellular diffusion and claudins primarily determine the types of molecules that freely diffuse through the junctions. Vascular-endothlial cadherin (VE-cadherin) mediates attachments between endothelial cells.