Haemostasis

Question 1

What are 4 things a clot is made up of

Answer 1

Platelets, fibrin, white and red blood cells

Question 2

Which of the following best defines the term ‘Bleeding Time’?

. The time taken for primary haemostasis to occur
. The time taken for secondary haemostasis to occur
. The total time taken for both primary and secondary haemostasis to occur
. The time taken for coagulation to occur

Answer 2

The time taken for primary haemostasis to occur

Question 3

What is the normal Bleeding Time length?

Answer 3

2-7 minutes

Question 4

Which two mechanisms initially stop bleeding?

Answer 4

. Constriction of blood vessel
. Formation of platelet plug

Question 5

How is the extrinsic clotting pathway activated?

Answer 5

Triggered by Tissue factor (factor III) that is released by damaged endothelial cells

Question 6

How is the extrinsic clotting pathway activated?

Answer 6

Triggered by Tissue factor (factor III) that is released by damaged endothelial cells

Question 7

How is the intrinsic clotting pathway activated?

Answer 7

Triggered by blood coming into contact with collagen fibres in the broken wall of a blood vessel

Question 8

Provide three situations in which blood clotting may be impaired

Answer 8

. When taking anticoagulant medication
. Liver disease
. Inherited diseases such as haemophilia a,b,c
. Von Willebrand disease

Question 9

Which Factor activates the extrinsic clotting pathway?

Question 10

After clot retraction, it is eventually destroyed. What is this process called?

Question 11

Which test is used to measure the intrinsic clotting pathway?