STEVE GSCHMEISSNER / SCIENCE PHOTO LIBRARY STEVE GSCHMEISSNER / SCIENCE PHOTO LIBRARY
Foetal blood vessel. Coloured scanning electron micrograph (SEM) of a section through a freeze- fractured foetal blood vessel. The vessel is filled with red blood cells (erythrocytes). Some of the erythrocytes have also been fractured, exposing their nuclei (brown). Red blood cells are only nucleated up until the fourth month of gestation.
Model release not required. Property release not required.