Figure 8.

Electron microscope images of a rat venular microvessel (VM). (a) Cross-section of a VM in rat mesentery. There are seven endothelial cell (EC) clefts, C1–C7, with all of the cleft exits covered by neighboring pericytes (PCs). PCs are immediately underneath ECs. There are two fibroblasts (fib.) outside PCs. The blowout shows C2 covered by a PC with a trapped microdomain (TM) of uniform thickness in between. (b) An enlarged view showing a cleft exit covered by a PC, creating a TM of roughly uniform thickness except at the narrow exit. Reprinted from Ref. 242.