False colour scanning electron micrograph (SEM) of pollen grains of Timothy grass,Phelum pratense,also known as cat's-tail. A germinating pore is visible on some grains. A summer grass pollen dispersed by the wind,it is a major cause of hay fever (Allergic rhinitis & pollenosis). Sufferers produce a sensitising antibody,immunoglobin E (IgE),which attaches to cells in the nose & eyes. It reacts with inhaled pollen ,causing the release of various chemicals including histamine. Histamine causes the mucous membranes of the nose,eyes & throat to swell & become inflamed,bringing on the familiar symptoms of hay fever. Magnification: X66 at 35mm size. Original is bw print B786/133 | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Burgess, Dr. Jeremy |
Taille de l’image : | 5102 px × 3488 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |