Week 5 - Haemostasis, Thrombosis and Embolism

Question 1

Outline features of the platelet release reaction.

Answer 1

1. ATP –> ADP
2. ADP, thromboxane A2 cause platelet aggregation
3. 5HT and platelet factor 3 also released
4. PF3 important in coagulation
5. Platelets coalesce after aggregation

Question 2

State four thrombin inhibitors.

Answer 2

1. Anti-thrombin III
2. Alpha-1 antitrypsin
3. Alpha 2 macroglobulin
4. Protein C and S

Question 3

State 2 types of fibrinolytic therapy that can be used.

Answer 3

1. Streptokinase

2. tPa

Question 4

State some anti-thrombotic substances produced by the endothelium.

Answer 4

1. Prostacyclin
2. Nitric oxide
3. Thrombomodulin
4. Plasminogen activators

Question 5

State the predisposing factors for thrombosis.

Answer 5

1. Abnormalities of the vessel wall: direct injury, inflammation, atheroma
2. Abnormalities of blood flow: stagnation, turbulence
3. Abnormalities of blood components: smokers, post-partum, post-op

Question 6

State the features of arterial thrombi.

Answer 6

1. Pale
2. Granular
3. Lines of Zahn
4. Lower cell content

Question 7

State the features of venous thrombi.

Answer 7

1. Soft
2. Gelatinous
3. Deep red
4. Higher cell content

Question 8

Outline the features of organisation of the thrombus.

Answer 8

1. Reparative process
2. In growth of fibroblasts and capillaries (similar to granulation tissue)
3. Lumen remains blocked: no restoration of flow

Question 9

Define embolism.

Answer 9

Blockage of a blood vessel by a solid, liquid or gas at a site distant from its origin