What are platelets in the blood?

1 Answer
Jul 7, 2016

Platelets are cell fragments floating in blood plasma. They help in clotting of blood around injuries.

Explanation:

Platelets form inside bone marrow by fragmentation of cellular extensions of Megakaryocytes: then they enter circulation. Such cell fragments lack nuclei. Platelets are also called thrombocytes.

Injury to capillary endothelium leads to adhesion and aggregation of platelets in the area. This leads to initiation of coagulation of blood, assisted by other clotting factors.

Number of platelets vary in blood: normal platelet count is considered to be 1.5 lakh to 4 lakh per microlitre of blood. Platelet count diminishes rapidly in hemorrhagic fever like Dengue.