Saturday, November 3, 2012

Formed from the mesenchyme, the endothelium is a layer of specialized epithelial cells which lines the inner walls of blood vessels, heart cavities, and lymph vessels. The cells of the endothelium are flat and a basal membrane separates them from the underlying tissues. In the glomeruli of the kidney nephrons, the endothelial cell cytoplasms have pores which make them permeable.