Lymphocyte white blood cells. Computer artwork of lymphocyte white blood cells, showing their nuclei (red, centre). Lymphocytes, like all white blood cells, are part of the immune system. They are divided into either B cells or T cells. B cells mature in the bone marrow and are responsible for humoral immunity; they recognise a specific site on the surface of a pathogen or foreign object (antigen), which they bind to before producing antibodies to destroy it. T cells mature in the thymus and are involved in cell-mediated immunity, which does not rely on antibodies to fight antigens, but the activation of other immune cells.
Science Photo Library was founded in 1981 by Michael Marten, one of the authors of "Worlds Within Worlds", a book exploring different ways to observe the universe - from electron micrographs, to images of earthrise taken from the Apollo spacecraft. When Marten started receiving requests for the beautiful images in the book, he had an idea of setting up Science Photo Library.
Since then, Science Photo Library has continued to work alongside world acclaimed photographers and the leading science and medical experts to provide a central source of the best science and specialist imagery available. Although the collection started with scientific images, it has grown to encompass all aspects of science and their impact on everyday life.
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