This slide shows a section taken from the kidney.  Note the simple squamous epithelial cells that form the wall of Bowman's capsule, which  receives a filtrate from a tuft of capillaries called the glomerulus. Because it is made up of a single layer of scale-like cells, simple squamous epithelium is well suited for rapid diffusion and filtration.  These cells look hexagonal in surface view but when viewed from the side, they appear flat with bulges where nuclei are located.