Clotting is a critical process that allows damaged parts of the body to be maintained. When damage occurs to skin tissue or other tissue in the body in the form of a cut, blood starts to clot. A blood clot, or blood coagulation, is part of a process called hemostasis, and, during this process, bleeding stops because blood vessels restrict and a platelet plug is formed. Blood clotting is essential to body repair and maintenance and, without it, a cut would continue to bleed, causing a person to hemorrhage. An abnormal clotting condition called thrombosis arises when blood cells produce clots that travel through the bloodstream causing vessels to clog.
If the body’s tissue is damaged by a cut or other injury, chemical signals called chemoattractants activate thrombocytes, also called platelets. Thrombocytes are a type of white blood cell and, when activated, they disperse proteins within the body that work to seal damaged tissue. These white blood cells float freely in the bloodstream and act quickly and efficiently to clot blood after injury.
Thrombocytes release the proteins thrombin and fibrinogen when activated by chemical signals after injury. Thrombin works to alter fibrinogen which causes fibrin to be produced. Fibrin is a substance that causes blood to clot and is released extensively from thrombocytes rapidly after an injury has occurred. It is released in connective layers that begin to form around the outside of the cut, eventually moving inward and forming a blood clot. When the damaged region is sealed, white blood cells called leukocytes move to the area in order to prevent any contamination that may occur from bacteria or viruses.
When blood clots normally, it will usually form a breach in a vessel; however, this does not happen in all cases. A condition called thrombosis arises when blood does not clot properly. Abnormal clotting of fibrin can result in masses that break away from the clot and move freely though the blood stream. The floating blood clot is called a thrombus.
A thrombus can cause arteries, capillaries, and veins to be blocked, which are vessels that are important in supplying blood to particular organs in the body. Blocking occurs when the thrombus eventually moves through a vessel that becomes smaller in diameter. Once the vessel is blocked, oxygen, blood, and nutrients that are vital to the body will not be able to move past it, making thrombosis a serious medical condition.