Platelets - formation, action and inhibition

Question 1

Alpha granule

Answer 1

Secreted proteins, clotting factors and PDGF

Question 2

Dense granule

Answer 2

Phospholipids, triglycerides, cholesterol, ATP/ADO and serotonin

Question 3

Normal number of platelets per mm3

Answer 3

150,000-400,000

Question 4

Life span of a platelet

Answer 4

8-12 days

Question 5

Where are platelets destroyed?

Answer 5

Spleen

Question 6

Why is aspirin a good anti-platelet?

Answer 6

Acts on arachidonic acid pathway

Question 7

How does clopidogrel stop platelets clotting?

Answer 7

Acts on binding site of platelets - they can’t adhere to endothelium

Question 8

Which clotting factor activates platelets?

Answer 8

vWF

Question 9

Which cytosolic component of platelets release ADP?

Answer 9

Dense granules?

Question 10

How are platelets destroyed by body?

Answer 10

Phagocytosis by macrophages in spleen

Question 11

Factors propagating platelet clot formation

Answer 11

ADP and thromboxane a2

Question 12

Precursor to thromboxane a2

Answer 12

Arachidonic acid

Question 13

MOA of clopidogrel bisulphate?

Answer 13

ADP receptor antagonist