What are platelets

The components of the human body are very complex, and the structure inside the body is equally complex. Blood is a very important part, and platelet is an important name in blood. It’s just that some people will develop platelet problems, which will make people nervous, so they should pay attention to examination and treatment. So what are platelets?

Platelets are small pieces of cytoplasm that detach from the cytoplasm of mature megakaryocytes in the bone marrow. Although megakaryocytes are the smallest in number among the hematopoietic cells in the bone marrow, accounting for only 0.05% of the total number of bone marrow nucleated cells, the platelets they produce are extremely important for the body's hemostatic function. When blood is lost due to vascular trauma, the functional activities of platelets in the physiological hemostasis process can be roughly divided into two stages: the first stage is mainly after the trauma occurs, platelets quickly adhere to the trauma site, aggregate into clusters, and form a relatively soft hemostatic plug; the second stage is mainly to promote blood coagulation and form a solid hemostatic plug.

Counting Meaning

The concept of platelet count refers to the number of platelets in a unit volume of blood. The normal value of platelet count is 125-320×10^9/L. Thrombocytopenia causes prolonged bleeding time, and bleeding may occur in severe injury or in an excited state. When the platelet count is <50×10^9/L, mild injuries may cause purpura of the skin and mucous membranes, and bleeding may occur after surgery; when the platelet count is <20×10^9/L, spontaneous bleeding often occurs. It is generally believed that when the platelet count is <20×10^9/L, prophylactic platelet transfusion is required. If the platelet count is >50×10^9/L and the platelet function is normal, there will be no obvious bleeding during the operation.

1. Thrombocytosis: When the platelet count is >400×10^9/L, it is thrombocytosis. Primary thrombocytosis is common in myeloproliferative diseases, such as chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, etc.; thrombocytosis is common in patients with acute and chronic inflammation, iron deficiency anemia and cancer. This type of increase generally does not exceed 500×10^9/L. The situation improves after treatment and the platelet count will quickly drop to normal levels. After splenectomy, platelet count will increase significantly, often higher than 600×10^9/L, and then slowly decrease to the normal range.

2. Thrombocytopenia: When the platelet count is <100×10^9/L, it is thrombocytopenia, which is common in platelet production disorders such as aplastic anemia, acute leukemia, acute radiation sickness, etc.; increased platelet destruction, such as idiopathic thrombocytopenic purpura, hypersplenism, Gaucher disease, etc., excessive consumption such as disseminated intravascular coagulation, familial thrombocytopenia such as giant platelet syndrome, etc.