Images Dated 4th June 1997

Coloured SEM of section through a human arteriole

Arteriole. Coloured scanning electron micrograph (SEM) of a cross-section through a small human artery known as an arteriole. This blood vessel reveals red blood cells travelling through its central lumen. Its inner wall (tunica intima) is thin and appears folded, comprising an endothelial lining and a thin elastic layer which stretches. A thicker tunica media layer (pink) makes up much of the wall of the arteriole, and is almost entirely composed of smooth muscle cells. An outer tunica adventitia layer merges with surrounding connec- tive tissue (yellow). These layers enable the arteriole to expand and contract, regulating the arterial blood pressure. Magnification: unknown

© STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY

Colored Sem Bifido Bacteria - Gram Pos. Rods

Purple Colorized Version. Colored Sem Bifido Bacteria - Gram Pos. Rods

© Custom Medical Stock Photo

Purple Colorized Colored Sem Bifido Bacteria Gram Pos Rods