What is the role of platelets in blood coagulation?

Many people often confuse thrombocytopenia and leukemia. In fact, they are different. We must learn to distinguish them clinically. When conducting a routine blood test, the number of platelets is a very important examination indicator. This is because platelets play a very important role in the human body. For example, they have aggregation function. Platelets also have adhesion function, etc., especially platelets play an irreplaceable role in coagulation.

The role of platelets in blood coagulation:

Platelets play an important role in the coagulation process, and a variety of platelet factors are involved in the blood coagulation process. Among them, platelet factor 3 (PF3) is more important. PF3 is a lipoprotein that acts as a surface catalyst in the reaction of activating factor X with factors IXa, VIII and Ca2+, and subsequently activating thrombin with factors Xa, V and Ca2+, thereby accelerating the process of blood coagulation.

The main function of platelets is to promote hemostasis and accelerate coagulation. Platelets also have the function of maintaining the integrity of capillary walls. During the process of hemostasis and coagulation, platelets have the functions of forming blood clots, plugging wounds, and releasing various factors related to coagulation. At the rupture of small blood vessels, platelets aggregate into platelet plugs to block the rupture and release adrenaline, 5-hydroxytryptamine and other substances that have the effect of constricting vasoconstriction. It is one of the important factors that promote blood coagulation.

Platelets also have the function of nourishing and supporting capillary endothelial cells, reducing the fragility of capillaries.

Abnormal platelet quantity and quality can cause bleeding diseases. A decrease in platelet count is seen in thrombocytopenic purpura, hypersplenism, aplastic anemia and leukemia. Increased numbers are seen in diseases such as essential thrombocythemia and polycythemia vera. Abnormal quality may be seen in thrombasthenia.

Since the 1960s, it has been confirmed that platelets have the function of phagocytosing viruses, bacteria and other particles. Platelets are noteworthy for their ability to engulf viruses. There is no nuclear genetic material in platelets, so viruses engulfed by platelets lose the ability to proliferate. Clinically, thrombocytopenia is also seen in patients with viral diseases. Therefore, platelets may constitute the body's line of defense against viruses, just like skin, mucous membranes and white blood cells.