Chapter 6 - Section 6.4 - Platelets and Blood Clotting - Check Your Progress - Page 123: 1

Platelets, prothrombin activator, prothrombin, thrombin, fibrinogen, and fibrin. When a blood vessel is ruptured platelets flock to the site of the damage and release prothrombin activator. This converts prothrombin into thrombin. Thrombin breaks two amino acid chains from a fibrinogen molecule. These fragments of amino acids join together to form fibrin which prevents massive blood loss.

Platelets, prothrombin activator, prothrombin, thrombin, fibrinogen, and fibrin. When a blood vessel is ruptured platelets flock to the site of the damage and release prothrombin activator. This converts prothrombin into thrombin. Thrombin breaks two amino acid chains from a fibrinogen molecule. These fragments of amino acids join together to form fibrin which prevents massive blood loss.