Physiology of Hemostasis and Thrombosis
Start with the big picture
The lesson follows hemostasis from the short-lived vascular response through primary hemostasis, where platelet adhesion, activation, and aggregation form an unstable plug, and secondary hemostasis, where thrombin and fibrin stabilize it. It outlines the extrinsic, intrinsic, and common coagulation pathways, including the roles of vitamin K and natural anticoagulant mechanisms. Fibrinolysis and the endothelium’s antithrombotic properties provide further checks on clot formation. The topic then considers thrombosis through Virchow’s triad, contrasts platelet-rich arterial thrombi with fibrin- and red-cell-rich venous thrombi, and introduces laboratory measures such as PT/INR, aPTT, bleeding time, and D-dimer.
What you'll learn
- Describe the vascular response and stages of primary and secondary hemostasis.
- Distinguish the extrinsic, intrinsic, and common coagulation pathways and their laboratory assessments.
- Explain how vitamin K, natural anticoagulants, endothelium, and fibrinolysis regulate clot formation.
- Relate Virchow’s triad and thrombus composition to thrombosis.
- Identify the roles of bleeding time and D-dimer in hemostasis assessment.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
