Haemostasis Flashcards
1
Q
What are the elements of the haemostatic response? (5)
A
- Blood vessels - vasoconstriction
- Platelets - platelet plug formation
- Clotting factors - coagulation phase
- Coagulation inhibitors
- Fibrinolysis
2
Q
What does haemostasis balance?
A
Excessive bleeding Vs excessive clotting
3
Q
What is the most immediate protection against blood loss?
A
Vasoconstriction
4
Q
How long does vasoconstriction last?
A
A few seconds - minute
5
Q
What chemical is released from platelets?
A
Serotonin
6
Q
Where are platelets produced?
A
Bone marrow
7
Q
What are platelets made from?
A
Fragments of megakaryocyte cytoplasm (1 makes 4000)
8
Q
What is platelet production controlled by?
A
- Number of circulating platelets (negative feedback)
- Thrombopoietin (TPO) released (increases platelet numbers)
