Osmosis video - Platelet plug formation (primary hemostasis)

Platelet plug formation, also known as primary hemostasis, is the first step of hemostasis and is the process where a platelet plug forms to prevent further loss of blood from a damaged vessel. It is divided into five stages: endothelial injury, exposure, adhesion, activation, and aggregation. After the platelet plug is formed, it is not a strong enough barrier to stop the bleeding completely, it is further reinforced by secondary hemostasis, which is the process by which a protein called fibrin is used to create a more stable clot, also called clot retraction.