clotting cascade
hemorrhage
homeostasis
Blood circulates through a series of tubes (arteries and veins). Damage to these vessels
must rapidly be repaired to minimize fluid loss. Several plasma proteins participates in a
_____ ______ that rapidly form a clot at a damage site to minimize blood loss
(________) and to maintain _______ (do not want to clot too much or too little).
homeostasis
_______ refers to the maintenance of the fluid states of the blood. This requires a
delicate balance between procoagulation (clot formation), anticoagulation and
fibrinolysis (clot dissolution). Dozens of plasma proteins are involved, as well as tissue
proteins, blood platelets and the surfaces of endothelial calls that line vessels. Defects
in any of these components may contribute to pathological bleeding or thrombosis
(clotting).
1. Vasoconstriction (damage to vessel walls results in narrowing of blood vessel
diameter)
2. Formation of a hemostatic plug (platelets bind to the site of damage (adhesion),
release signaling factors (activation), and stick together to form a scaffold for
clotting (aggregation)
3. Formation of a blood clot (cross-linked fibrin reinforces the platelet plug to
form a clot via a cascade of enzymatic reactions)