Cell releasing histamine. Computer illustration of a mast cell releasing histamine (blue bubbles) in a blood vessel. Mast cells are a type of leucocyte (white blood cell). They contain the chemical mediators histamine,serotonin and heparin. Histamine is released from mast cells in response to an allergen (yellow,spiky),causing a localized inflammatory immune response. When an allergen is encountered,B cells (not seen) produce antibodies which bind to protein receptor molecules on the surface of the mast cell. When two antibodies are cross-linked with an antigen the cell is activated to release its histamine by exocytosis. Histamine causes capillaries to dilate,smooth muscle to contract,and many other effects | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Singh, Harvinder |
Bildgröße: | 4832 px × 3624 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |