Practise sequencing thromboplastin, thrombin and fibrin formation, explaining anticoagulant action, and linking clots in named vessels to restricted flow using marked evidence.
Stents are used in the treatment of atherosclerosis.
Stents widen the diseased coronary artery so that blood can flow through to the heart muscle.
The diagram shows a stent.
Stents can damage the endothelial cells lining the artery and trigger the formation of a blood clot.
Patients who have a stent fitted are given anticoagulants.
Explain how damage to the endothelial cells results in the formation of thrombin.
The photograph shows a tropical bont tick.
This bont tick produces a peptide called variegin.
Variegin binds to the active site of thrombin and prevents blood clotting.
Explain how variegin prevents blood clotting.