The human body has a rapid and effective mechanism to deal with the unexpected loss of blood. Called coagulation, or blood clotting, this process depends on a series of events and the presence of several different proteins, enzymes, calcium and vitamin K. The protein called fibrin is one of the most important elements needed for blood to clot.
Definition
Fibrin is an insoluble protein that’s essential for blood clotting and wound healing. Fibrin molecules are shaped like long threads that interlace to form a mesh, which then traps platelets and red blood cells to create a clot.
Blood Clotting
Whenever an injury tears a blood vessel, a series of events begins to stop the bleeding and heal the wound. The damaged vessel tightens, and sticky blood platelets flood the damaged area. Another blood protein that’s produced by the liver, called fibrinogen, is converted into fibrin; the fibrin fragments weave a lattice over the injured place in the blood vessel. Blood platelets attach to the fibrin, forming a clump that becomes a blood clot. Over time, this clot hardens to become a scab that protects the area while new tissue grows.
Disorders
Fibrin-platelet clots can break off and travel through blood vessels to create another clot anywhere in the body. This clot, called an embolism, can cause life-threatening conditions, including a stroke, venous thrombosis in the legs or pulmonary embolism in the lungs. Emboli may continue to grow and ultimately block the vessel, they can shrink and leave a scar or be dissolved through the body's natural process or through medication. Fibrin is also a contributing factor in cardiovascular disease. Plaque that builds up on the walls of blood vessels consists of cholesterol, cellular waste, calcium and fibrin. The plaque thickens the vessel wall, while the fibrin and calcium harden and cause the wall to lose critical elasticity. Excessive clotting disorder is a condition in which the clotting process is not properly regulated, resulting in excessive clot formation. Overproduction of fibrin may be related to arthritis, multiple sclerosis and Alzheimer’s disease.
Medical Uses
Fibrin sealants are commercially produced from fibrinogen and thrombin, which is the enzyme that turns fibrinogen into fibrin. The result is a tissue adhesive used during surgery to control bleeding, to provide the delivery of medications and to speed clot formation and wound healing. Fibrin sealants can be used in very small areas, they're absorbed by the body during healing and they lower the risk of postoperative inflammation or infection, the Encyclopedia of Surgery notes.
References
- Encyclopedia Britannica: Fibrin
- The Franklin Institute: Platelets
- The University of Chicago Medical Center: Peripheral Vascular Disease
- American College of Chest Physicians: A Patient’s Guide to Antithrombotic and Thrombolytic Therapy
- Lab Tests Online: Excessive Clotting Disorders
- Encyclopedia of Surgery: Fibrin Sealants
