ATI Pathophysiology Practice Exam

Platelets play a crucial role in hemostasis, which is the process that prevents and stops bleeding, or hemorrhage. Their primary function is to aggregate at the site of vascular injury, forming a temporary plug that helps to seal the damaged blood vessel and prevent further blood loss. This aggregation process is facilitated by various adhesion molecules and signaling pathways that activate platelets when they encounter exposed collagen and other substances due to a breach in the endothelium.

In addition to forming a plug, platelets also release substances that promote further aggregation and recruitment of additional platelets, reinforcing the plug. They contain granules filled with signaling molecules such as adenosine diphosphate (ADP) and thromboxane A2, which are vital for the promotion of further platelet activation.

While clotting factors are essential for the coagulation cascade, they are primarily produced in the liver, making a different contribution to hemostasis. The role of dissolving blood clots, known as fibrinolysis, is performed mainly by plasmin, not platelets. Finally, the transport of oxygen in the bloodstream is a function of red blood cells, not platelets. Thus, the primary role of platelets is indeed to aggregate and form a plug at the