Haemostasis Flashcards
what is haemostasis
Haemostasis: blood (haem) stop/stand still (stasis)
The haemostasis is strictly controlled
what are the 5 major components of the haemostatic system?
- Blood vessels
- Platelets
- Coagulation factors
- Coagulation inhibitors
- Fibrinolysis
what is primary haemostasis?
- Platelets respond to the vessel wall
injury - Platelets adhere to the vessel wall
- A primary platelet plug is formed
what is secondary haemostasis?
- Activation of the intrinsic and
extrinsic coagulation pathways - Activation of the common pathway
- Fibrin strand formation and
strengthening of the platelet plug
describe Blood Vessels in Haemostasis
describe Von Willebrand Factor (vWF)
discuss characteristics of Platelets
describe platelet storage granules
describe the primary haemostasis process
what are the results of primary haemostasis?
Primary haemostasis forms a temporary and weak platelet plug
Unstable and needs strengthening
secondary haemostasis
what is the need for secondary haemostasis?
A weak platelet plug needs strengthening by coagulation
factors (secondary haemostasis)
what is secondary haemostasis strengthened by
Coagulation factors are mostly proenzymes (zymogens)
where are most coagulation factors synthesised?
liver
what do proenzymes require to carry out their function
Proenzymes require activation to carry out their function
* Active form of a coagulation factor is denoted ‘a’
what are the four stages of haemostasis?
Explain the Coagulation Cascade