How is thromboplastin released?

Thromboplastin, also known as tissue factor, is released from damaged tissues and activated endothelial cells in response to injury. When blood vessels are damaged, the exposure of collagen and other underlying structures triggers the release of thromboplastin into the bloodstream. This protein then interacts with factor VII to initiate the extrinsic pathway of coagulation, ultimately leading to the formation of a blood clot.