4.3.7 - Blood clotting and Atherosclerosis

Question 1

What happens first during a blood clot?

Answer 1

Thromboplastin catalyses the conversion of prothrombin to thrombin.
This requires calcium ions.

Question 2

What does thrombin do in a blood clotting cascade?

Answer 2

Converts fibrinogen to fibrin.

Question 3

what happens after fibrin forms a mesh of fibres to cover wounds?

Answer 3

Platelets get trapped in the fibrin mesh causing a clot.

Question 4

What does fibrin do in blood clotting?

Answer 4

Forms a mesh of fibres that cover wounds.

Question 5

What happens after platelets get trapped in fibrin mesh?

Answer 5

Special proteins in the platelets contract making the clot tighter and tougher to form a scab. This helps to protect the skin and vessels underneath.

Question 6

What happens first during atherosclerosis?

Answer 6

Slight damage to endothelial cells can lead to the start of a plaque deposit.

Question 7

What happens after the start of a plaque deposit forms in an artery?

Answer 7

Blood platelets form a cap over the plaque which narrows the artery.

Question 8

What can happen if the artery blocks around the heart?

Answer 8

Can cause a stroke or heart attack.

Question 9

What factors can increase risk of atherosclerosis?

Answer 9

High blood pressure
Chemicals in cigarettes from smoking
High cholesterol

Question 10

Why is atherosclerosis more likely to occur in arteries?

Answer 10

The pressure of the blood is higher.

Question 11

What is the name of cells on the lining of the artery?

Answer 11

Endothelial cells

Question 12

To summarise, how can a blood clot form in an artery?

Answer 12

1) Damage to artery wall leads to plaque called an atheroma.
2) Blood, platelets form a cap over the plaque which narrows the artery.
3)Fibrin can cause red blood cells to become trapped
4) This can cause a blood clot (thrombosis)
5) f this happens in a coronary artery it can cause a heart attack