White blood cell. Coloured scanning electron micrograph (SEM) of a lymphocyte cell,a type of white blood cell and part of the immune system. Lymphocytes are divided into either B-cells or T- cells. B-cells mature in bone marrow and are responsible for humoural immunity; they operate by recognising a specific site on the surface of a pathogen or foreign object (antigen),which they then bind to before producing antibodies to destroy that antigen. T-cells mature in the thymus and are involved in cell-mediated immunity,which does not rely on antibodies to fight antigens,but rather the activation of macrophages,NK-cells,cytotoxic T-lymphocytes and various cytokines | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Gschmeissner, Steve |
Bildgröße: | 4000 px × 3009 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |