The three types of capillary blood vessels are continuous, fenestrated, and discontinuous, with continuous being the least porous of the three and discontinuous capillaries being extremely high in permeability. Continuous blood capillaries have the smallest intercellular clefts, with discontinuous blood capillaries having the largest intercellular clefts, commonly accompanied with gaps in the basement membrane6.Often, fluid is forced out of the capillaries through the intercellular clefts. Fluid is push out through the intercellular cleft at the arterial end of the capillary because that's where the pressure is the highest.