Question

___________________ functions; adhere to expose collagen fibers at site of vessel damage-- homeostatic plug; release serotonin, and undergo platelet degranulation--- release platelet thromboplastin (PF3) ----- neutralizes anticoagulants in intrinsic phase of clotting reaction.

Answer 1

Platelets play a vital role in hemostasis by forming a plug at the site of vascular injury and releasing substances like ADP and serotonin to strengthen the plug and promote vasoconstriction. They also release PF3 that neutralizes anticoagulants, aiding in the clotting process.

Step-by-step explanation:

The question revolves around the functions of platelets during the hemostatic process, particularly in the formation of a platelet plug and the intrinsic pathway of the clotting reaction. Platelet plug formation is a significant step in stopping blood loss following vascular injury. When blood vessels are damaged, platelets adhere to exposed collagen fibers and undergo activation and degranulation. Key substances such as adenosine diphosphate (ADP) and serotonin are released. ADP reinforces the aggregation of more platelets, while serotonin contributes to vasoconstriction, maintaining the plug's integrity. Platelet factor 3 (PF3), also known as platelet thromboplastin, is released and plays a crucial role in neutralizing anticoagulants, promoting the progression of the clotting cascade.