Final answer:
D-dimers increase in DIC because they are byproducts of clot degradation that occurs when the body breaks down excessive clots. During clot formation, platelets, clotting factors, and fibrinogen interact to form a stable fibrin clot.
Step-by-step explanation:
D-dimers are increased in disseminated intravascular coagulation (DIC) because they are one of the byproducts of clot breakdown (fibrinolysis). When clots are formed in the blood vessels, the body naturally initiates a process to break them down to prevent excessive clotting. This process involves the conversion of plasminogen into plasmin, which then degrades the fibrin matrix of clots into fibrin degradation products, including D-dimers.
The constituents of the blood that interact to form a fibrin clot include platelets, which form a plug at the site of blood vessel injury; clotting factors, which lead to the generation of thrombin; and fibrinogen, which is converted by thrombin into fibrin to stabilize the clot. This complex process is known as the coagulation cascade.