plättchen

**Plättchen**

Plättchen, also known as platelets or thrombocytes, are small, disc-shaped cells found in the blood of mammals and some other vertebrates. They play a crucial role in blood clotting, a process essential for preventing excessive bleeding when blood vessels are injured. Unlike red blood cells or white blood cells, platelets lack a nucleus and are produced in the bone marrow from megakaryocytes.

The primary function of platelets is to form clumps, known as platelet plugs, at sites of injury to initiate the clotting cascade. They release various signaling molecules that help recruit additional platelets and promote the formation of a stable blood clot. This process involves the activation of coagulation factors, leading to the conversion of fibrinogen into fibrin, which forms a mesh that stabilizes the clot.

In addition to their role in hemostasis, platelets are involved in other physiological processes, such as wound healing and the regulation of vascular tone. They also participate in immune responses, though their exact mechanisms in this context remain under study. Abnormal platelet function or counts can lead to conditions such as bleeding disorders (e.g., thrombocytopenia) or increased risk of thrombosis (e.g., thrombocytosis).

Platelets circulate in the bloodstream for approximately 9–12 days before being removed by the spleen or liver. Their lifespan is shorter than that of red blood cells, contributing to the need for continuous production to maintain proper blood clotting capacity. Monitoring platelet levels is a common practice in medical diagnostics to assess overall health and detect potential disorders.