what is the plug composed of during the clotting response?
They bind to the injured cells in a wound as well as to each other. During this activation process, the platelets become more rounded in shape and develop spikes. Activated platelets form a mesh, or a platelet plug, that covers and fills a wound. The plug temporarily stops bleeding and is a very helpful emergency response to a wound. It's quite weak, however, and may be removed by flowing blood unless it's strengthened by a blood clot. The activated platelets in a plug release chemicals that are needed by the blood clotting process.