All of the following statements regarding arterial versus venous thrombosis are correct EXCEPT:

Explanation

## Arterial vs. Venous Thrombosis: Key Distinctions ### Composition and Pathogenesis | Feature | Arterial Thrombus | Venous Thrombus | |---------|-------------------|------------------| | **Composition** | Platelet-rich, fibrin-rich; minimal RBCs ("white clot") | RBC-rich, fibrin-rich; minimal platelets ("red clot") | | **Primary cause** | Endothelial injury (atherosclerosis, trauma) | Blood stasis (immobility, atrial fibrillation, venous obstruction) | | **Flow conditions** | High-flow, high-shear environment | Low-flow, low-shear environment | | **Embolization risk** | High — easily dislodged | Lower — more adherent to vessel wall | | **Location** | Heart, aorta, coronary/cerebral arteries | Deep leg veins, right heart chambers, pelvic veins | ### Why Option 3 is Incorrect **Key Point:** Venous thrombi form *primarily due to blood stasis*, not endothelial injury. While endothelial injury can contribute, the dominant mechanism in venous thrombosis is the Virchow's triad component of abnormal blood flow. **High-Yield:** In low-flow venous systems, platelets have more time to aggregate and fibrin accumulates without being washed away. Endothelial injury is the *primary cause* of arterial thrombosis (where high shear forces require platelet activation), but stasis is the primary cause of venous thrombosis. **Clinical Pearl:** This distinction explains why: - Arterial thrombi are associated with atherosclerosis, hypertension, and smoking (endothelial injury) - Venous thrombi are associated with immobility, surgery, cancer, and hypercoagulable states (stasis + hypercoagulability) **Mnemonic:** **ARTERIAL = Atherosclerosis/Injury-driven; VENOUS = Stasis-driven** [cite:Robbins 10e Ch 4]