Platelets in Physiology: Structure, Formation and Role in Hemostasis and Blood Clotting скачать в хорошем качестве

Platelets in Physiology: Structure, Formation and Role in Hemostasis and Blood Clotting

Platelets, also known as thrombocytes, are small, non-nucleated cell fragments derived from megakaryocytes in the bone marrow. They play a crucial role in hemostasis, which is the process that prevents blood loss after vascular injury. The normal platelet count ranges from 150,000–400,000/µL of blood. Structurally, platelets contain granules (alpha and dense granules) that store important substances such as clotting factors, serotonin, calcium, and platelet-derived growth factor (PDGF). When a blood vessel is injured, platelets adhere to the damaged endothelium, become activated, and aggregate to form a temporary platelet plug. Their major functions include: Primary hemostasis (formation of platelet plug) Activation of coagulation cascade Release of clotting factors and vasoconstrictors Wound healing and tissue repair Maintenance of vascular integrity Abnormalities in platelet number or function can lead to bleeding disorders (thrombocytopenia) or excessive clot formation (thrombocytosis). #Platelets #Thrombocytes #Physiology #Hemostasis #BloodClotting #Coagulation #Megakaryocytes #Hematology #PlateletPlug #WoundHealing