When a blood vessel gets injured, the first event to occur in hemostasis is:
1. The endothelial lining is damaged, exposing collagen proteins to the blood.
2. The injured blood vessel is dilated by newly released chemicals to let in defense cells.
3. Platelets become "sticky" and a platelet plug is formed near the injury site.
4. A web of fibrin protein strands tightly interweave the platelet plug.

Assertion: In patients of liver failure the risk of bleeding is increased.
Reason: Liver synthesizes most of the clotting factors and activates Vitamin K.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

The fraction of an anticoagulated blood sample called the "buffy coat" contains
1. red blood cells
2. white blood cells
3. platelets
4. white blood cells and platelets

The cytoplasmic granules released by thrombocytes during platelet plug formation, which attract more platelets to the plug are:
1. prostacyclin and NO
2. erythropoietin and bilirubin
3. heparin and plasmin
4. ADP and thromboxanes