Haemostasis (coagulation) Flashcards
What does haemostasis achieve?
- keep blood liquid
- Limit the bleeding by forming a blood clot, whilst also maintaining liquid blood flow through the damaged vessel
- Removal of the blood clot upon healing
summarise primary haemostasis
summarise secondary haemostasis
summarise Fibrinolysis
what are the 3 layers of large blood vessel walls?
Intima
Media
Adventitia
intima structure and function
thin layer of endothelial cells lining the walls of the lumen.
shields the basement membrane
media structure and function
thick layer of smooth muscle cells that allow for contraction and relaxation – important for arterial pulse
adventitia structure and function
thick outer layer of collagen and fibroblasts. Protect and anchor the blood vessel
in what position in the blood vessel wall is the external elastic lamina and what is it’s function?
between the media and adventitia – allows elasticity (stretch and recoil)
what does it mean that the Subendothelia of intima are antithrombotic until injury, when they become thrombogenic?
they only have a high tendency to clot after injury (release endothelin-1 to vasoconstrict and restrict blood loss)
why is tissue factor important in secondary haemostasis?
triggers the enzymatic reactions that increase thrombin (factor IIa) production – this
what is VWF?
what are the functions of VWF?
what are some specific functions of the amino acids in VWF?
on VWF, what does amino acid A1 do?
on VWF, what does amino acid A3 do?
on VWF, what does amino acid C1 do?
on VWF, what does amino acid D’D3 do?
what is the difference in blood type O in terms of VWF?
how do platelets interact with VWF and why?
to initiate
why is it important that platelets are negatively charged?
what part of the platelet structure makes it negatively charged?
the middle membrane is phospholipid rich
why is the platelet cytoskeleton important? what affect does it have on the platelet?
function dependant on shape
why is it important that the platelet maintains it discoid shape?
