False-colour scanning electron micrograph (SEM) of a pollen grain from cocksfoot grass,Dactylis glomerata,a major cause of hay fever. The SEM shows a germinating pore from which a pollen tube emerges. Cocksfoot pollen is a summer grass whose pollen is dispersed by the wind. Hay fever suffer- ers produce a sensitising antibody,immunoglobin E (IgE),which attaches to cells in the nose & eyes. It reacts with inhaled pollen (an allergen) causing the release of various chemicals including histamine. Histamine causes the mucous membranes of the nose,eyes & throat to swell & become inflamed,producing hay fever. Magnification: x330 at 35mm size,x830 at 6x6cm size | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Burgess, Dr. Jeremy |
Taille de l’image : | 4370 px × 4546 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |