Red blood cells (erthryoctyes) and white blood cells. Red blood cells are the most numerous of all the blood cells. Red blood cells are biconcave shape increases the surface area of the cell. There primary role is to transport oxygen throughout the body. White blood cells primary function is to fight infections. There are five major types of white blood cells. **On Page Credit Required** SEM X4500.
Coloured scanning electron micrograph (SEM) of a red blood cell squeezing out of a torn capillary. A capillary is the smallest type of blood vessel, often only just large enough for red blood cells to pass through.
An image of capillary, just wide enough for one red blood cell to squeeze through.
under a microscope/ red blood cells caught in the sticky web of a blood clot. The cell in the middle is a white blood cell.