Skin Wound Without platelets, you would repeatedly face the possibility of death, because you would lose great quantities of blood whenever you were injured. Immediately after a cut or tear in your skin occurs, your platelets clump together to plug the gap and discharge a substance that retards loss of blood.
Protein in the Blood
Fibrin strands then develop from a protein in the blood, and they rapidly weave the blood-clot structure. These strands cleave to the injured tissue, and confine platelets and blood cells within their network, thus strengthening it. Not long after the clot is formed, it constricts or shrinks, squeezing out watery plasma and drawing the sides of the wound together. The clot stems the flow of blood, fills the wound, and provides a framework for building new tissue.
As the injury heals, the coagulated material firms up into a dry, hard scab on underneath. There skin cells multiply, forming new tissue to fill in the break; white blood cells defend against infection and clean up formed to nourish the new cells.