What is needed for blood clotting?
Blood Clots. Blood clotting, or coagulation, is an important process that prevents excessive bleeding when a blood vessel is injured. Platelets (a type of blood cell) and proteins in your plasma (the liquid part of blood) work together to stop the bleeding by forming a clot over the injury.
Platelets are fewer in number than red blood cells, with a ratio of about 1 platelet to every 20 red blood cells. Platelets help in the clotting process by gathering at a bleeding site and clumping together to form a plug that helps seal the blood vessel.
- Clotting factors are proteins in the blood that control bleeding. Many different clotting factors work together in a series of chemical reactions to stop bleeding. This is called the clotting process. Problems with factor VIII and factor IX are known as hemophilia A and B, respectively.
- As clotting gets under way, each step releases chemicals that accelerate the process. This escalating process is a positive feedback loop that ends with the formation of a blood clot, which patches the vessel wall and stops the bleeding.
- FOUR MAIN PARTS OF THE CIRCULATORY SYSTEM
- HEART. "PUMP"
- BLOOD VESSELS. "TRANSPORT ORGANS"
- BLOOD. "TRANSPORT FLUID"
- LYMPHATIC SYSTEM. "DEFENSE SYSTEM"
If normal amounts of calcium, platelets, and tissue factors are present, prothrombin is converted to thrombin. Thrombin acts as a catalyst for the conversion of fibrinogen to a mesh of insoluble fibrin, in which all the formed elements are immobilized. Also called blood coagulation or thrombus formation.
- The chief element involved in clotting of blood is Calcium (Ca++), which by itself is the 4th clotting factor. It helps in activating many other clotting factors. Furthermore, it helps in conversion of prothrombin to thrombin, which is essential for clot formation.
- The average life span of circulating platelets is 8 to 9 days. Life span of individual platelets is controlled by the internal apoptotic regulating pathway, which has a Bcl-xL timer. Old platelets are destroyed by phagocytosis in the spleen and liver.
- The name hemoglobin is derived from the words heme and globin, reflecting the fact that each subunit of hemoglobin is a globular protein with an embedded heme group. Each heme group contains one iron atom, that can bind one oxygen molecule through ion-induced dipole forces.
Updated: 28th November 2019