blood disorders
How Blood Clots
Introduction
Hemostasisis the body's way of stopping injured blood vessels from bleeding. Hemostasis includes clotting of the blood. Too little clotting can cause excessive bleeding from minor injury Too much clotting can block blood vessels that are not bleeding An abnormality in any part of the system that controls bleeding can lead to Bruising and Bleeding or Hemostasis involves three major processes: Narrowing (constriction) of blood vessels Activity of cell-like blood particles that help in blood clotting ( Platelets ) Activity of proteins found in blood that work with platelets to help the blood clot (clotting factors) When an injury causes a blood vessel wall to break, platelets are activated. They change shape from round to spiny, stick to the broken vessel wall and each other, and begin to plug the break. They also interact with other blood proteins to form fibrin. Fibrin strands form a net that entraps more platelets and blood cells, producing a clot that plugs the break. 