Final answer:
Heparin is used in hemodialysis primarily for its potent anticoagulant ability to prevent clot formation by inactivating factor X and opposing the conversion of prothrombin to thrombin, as well as its short-acting nature which allows for easy reversal of its effects.
Step-by-step explanation:
The special characteristics of heparin that make it particularly useful as an anticoagulant in hemodialysis are its ability to quickly and effectively inhibit the coagulation process. Heparin acts by binding to antithrombin, an anticoagulant that inactivates factor X and opposes the conversion of prothrombin (factor II) into thrombin in the common pathway of the coagulation cascade. Given that hemodialysis requires the movement of blood outside the body, where it is at increased risk for unwanted coagulation, heparin's rapid action helps maintain blood fluidity by preventing clot formation during the procedure.
In addition, heparin is short-acting, which means its effects are quickly reversible once the infusion is stopped. This is important in a clinical setting where control over the anticoagulant effect is necessary. Also, heparin is naturally present on the surfaces of cells lining the blood vessels, making it a substance that is compatible with the body's physiological systems.