Capillaries
- Thin-walled capillaries accept blood from arterioles
- Lumen not much wider than red blood cells
- Wall comprises endothelial cells with bulging nuclei
- The basement membrane supports the endothelial lining
- Pericytes often "embrace" the endothelial cells
- Endothelial cells have marginal folds of cytoplasm that overlap at their edges, cover tight intercellular junctions