This is an image of a small artery in a mouse eyelid that has formed a thrombus (blood clot). When a blood vessel is damaged, chemicals that attract platelets are released from the site of injury. Platelets in the flowing blood stick to the site, and in turn release attractants for even more platelets. A cascade begins that causes fibrinogen, a protein that is dissolved in blood, to polymerize into long fibers that form a mesh with the platelets, trapping blood cells and forming the clot. In this image, platelets and fibrin are not visible, only the trapped erythrocytes (red blood cells) and the artery wall.

To read more about blood clots, click here.

Art contributed by Don W. Pottle.