<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The tunica intima (New Latin "inner coat"), or intima for short, is the innermost tunica (layer) of an artery or vein . It is made up of one layer of endothelial cells and is supported by an internal elastic lamina . The endothelial cells are in direct contact with the blood flow . </P> <P> The tunicae of blood vessels are three layers--an inner layer (the tunica intima), a middle layer (the tunica media), and an outer layer (the tunica adventitia). </P> <P> In dissection, the inner coat (tunica intima) can be separated from the middle (tunica media) by a little maceration, or it may be stripped off in small pieces; but, because of its friability, it cannot be separated as a complete membrane . It is a fine, transparent, colorless structure which is highly elastic, and, after death, is commonly corrugated into longitudinal wrinkles . </P>

Which of the following types of blood vessels consists of only one cell layer