White blood cells & platelets. Coloured scanning electron micrograph (SEM) of a group of white blood cells (leucocytes) and activated platelets in human blood. The larger rounded white blood cells (coloured brown) play a role in the immune response of the body. At centre and far left are smaller platelets (thrombocytes, coloured purple). Platelets are non-nucleated cells found in large numbers in the blood. When inactive they are round or oval discs; activated they have dendritic processes, or pseudopodia (as seen here), and they may become star-shaped. When activated, platelets clump together and are involved in blood clotting. Magnification: unknown.

Photo website with Rights Managed and Royalty Free stock photos, images, illustrations and footage available for download immediately for commercial and editorial uses. Aflo is a leading independent supplier and producer of stock pictures and visual content. Search and find high quality images and video for design, print, web-use and publishing. Buy photos from our extensive collection of model released and property released sports images. Search some of the most beautiful travel and landscape pictures from our own photographers and license from our large collection of content, modern and archive, focusing on Japan. We provide free research. Register for personal account management and for full use of our Stock Photography website and start to download images now.