Surface view of strial vessel, prominence vessel, and external sulcus cells as revealed by scanning electron microscopy.

The stria vascularis and the spiral prominence in the lateral cochlear wall were observed with scanning electron microscopy (SEM) after dissolving out the epithelial layer and the basement membrane by tryptic digestion and HCl hydrolysis. The external sulcus cells have regularly arranged pegs and a fine basal interdigitation on the cell surface. The strial vessel and the spiral prominence vessel could be visualized well and the characteristic surface view of their periendothelial cells presented. The former has cytoplasmic processes with a fine branching appearance similar to red coral and the latter has bulged popcorn like processes. Their functional significance is discussed.