Platelet

What is Platelet?

A platelet is a small fragment of a cell found in the blood. When a blood vessel is damaged, platelets gather at the site and set off the clotting process, in which the soluble plasma protein fibrinogen is converted into insoluble fibrin. Fibrin forms a mesh of fibres across the wound that traps blood cells and forms a clot, which reduces the loss of blood and reduces the entry of pathogens through the damaged skin.

This definition is part of the Transport in Humans chapter in Cambridge O Level Biology.

Concepts related to Platelet

• fibrinogen
• fibrin
• pathogen entry

Common mistakes with Platelet

• “Platelets produce antibodies.” Why wrongPlatelets are cell fragments and do not make proteins to order. WriteLymphocytes produce antibodies. Platelets start the clotting process.