Introduction: Blood Cells
Blood contains several different types of cells. Some cells, such as red blood cells, carry oxygen to other cells. Other types of cells, such as white blood cells or leukocytes, provide protection from foreign cells and infectious agents. Cell fragments called platelets provide protection against bleeding. The red blood cells of different animals can have different structures.

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Still Image:
Human red blood cells 2
Individual disk-shaped blood cells appear nearly colorless when viewed under a microscope.
A drop of blood diluted with saline solution was mounted between a slide and coverslip using a silicon rubber spacer. The image was taken on an inverted compound microscope using a 40x DIC objective and a digital camera.