Haemostasis, Thrombosis And Embolism (6) Flashcards
0
Q
How do platelets help reduce blood loss?
A
- Adhere to damaged vessel wall
- Adhere to each other
- Forms a platelet plug
1
Q
What does homeostasis depend on?
A
- Vessel wall
- Platelets
- Coagulation system
- Fibrinolytic system
2
Q
What is the platelet release reaction?
A
- ATP -> ADP
- ADP thromboxane A2 cause platelet aggregation
- 5HT platelet factor 3 also released
- PF3 important in coagulation
- Platelets coalesce after aggregation
3
Q
How does coagulation occur?
A
- Series of inactive components -> active components (cascade)
- Prothrombin -> thrombin
- Thrombin stimulates fibrinogen -> fibrin
4
Q
How is coagulation tightly regulated?
A
- Balance of pro coagulant and anticoagulant factors
5
Q
What is Fibrinolysis?
A
- Breakdown of fibrin
- Plasminogen -> plasmin (catalysed by plasminogen activation)
6
Q
Give 2 examples of fibrinolytic factors
A
- Streptokinase
- TPA
7
Q
Give 4 examples of endothelium anti-thrombotic factors.
A
- Plasminogen activators
- Prostacyclin
- Nitrous oxide (NO)
- Thrombomodulin
8
Q
What is a thrombosis?
A
- Formation of a solid mass of blood within circulation system
9
Q
Why may a thrombosis form?
A
- Abnormalities of vessel wall
- Abnormalities of blood flow
- Abnormalities of blood components
10
Q
How may abnormalities of the vessel wall occur?
A
- Atheroma
- Direct injury
- Inflammation
11
Q
Why may abnormalities of blood flow occur?
A
- Stagnation
- Turbulence
12
Q
How may abnormalities of blood components occur?
A
- Smoking
- Post-op
- Post-partum (post-natal)
13
Q
What is the appearance of an arterial thrombus?
A
- Pale
- Granular
- Lines of Zahn
- Lower cells content
14
Q
What is the appearance of a venous thrombi?
A
- Soft
- Gelatinous
- Deep red (higher cell content)