Challenge Your Exam Readiness With Our Free Phlebotomy Practice Questions

Hemostasis proceeds through coordinated steps. Immediately after vessel injury, local vasoconstriction reduces blood flow. Platelets adhere to exposed subendothelium, become activated, and aggregate to form a primary platelet plug. Concurrently, the coagulation cascade generates thrombin, converting fibrinogen to fibrin, which stabilizes the plug—secondary hemostasis. After tissue repair, fibrinolysis (plasmin-mediated) gradually dissolves fibrin, restoring normal flow. Option B correctly sequences these events. Starting with fibrinolysis (Option A) is physiologically impossible; fibrin must form before it can be lysed. Option C scrambles the order. Option D ignores the essential role of coagulation factors in stabilizing the platelet plug. Understanding hemostasis underpins practical decisions in phlebotomy (e.g., prolonged pressure for anticoagulated patients, tube additive effects like citrate and EDTA) and clarifies why certain tests (PT/INR, aPTT, platelet function) evaluate different points in this process—knowledge commonly tested on certification exams.