Abnormalities of haemostasis

Question 1

front

Answer 1

back

Question 2

What are the 4 testsused to investigate the haemostatic system?

Answer 2

Platelet countProthrombin timeActivated partial thromboplastin timeFIbrinogen level

Question 3

A prolonged PT indicates a deficiency in what factor?

Answer 3

Factor 7

Question 4

A change in APTT indicates an issue with factors?

Answer 4

12, 11 and 9

Question 5

What activates von Willibrand factor?

Answer 5

Shear forces

Question 6

What function does vWF have?

Answer 6

Acts as an adhesion point for platelets and collagen

Question 7

Where can shear forces be large enough to activate vWB?

Answer 7

Within the arterioles and over atherosclerotic plaques within arteries

Question 8

What receptor on platelets binds to vWF?

Answer 8

GP 1b

Question 9

What does vWB factor bind to to begin with following injury?What receptors attaches other platelets to platelets attached to VWB factor?

Answer 9

Exposed collagenGPIIb/IIIa

Question 10

How many subtypes of von Willebrand disease are there?

Answer 10

3.Type 1 is a partial quantitative deficiency of VWFType 3 is virtually complete quantitative deficiency of VWFType 2 is qualitative, there are 4 subtypes of type 2

Question 11

What is the function of ADAMTS13 enzyme?

Answer 11

To cleave overly long VWF molecules

Question 12

What is the cause of thrombotic thrombocytopoenic purpura?
What is its pathophysiology?
What is the treatment?

Answer 12

Deficiency of ADAMTS13 enzyme either through congenital or auto-immune means.
Formation of extensive microthrombi throughout the circulation.
Plasma exchange, DO NOT TRANSFUSE PLATELETS!

Question 13

What converts plasminogen to plasmin?

Answer 13

tPA

Question 14

Cleavage of plasminogen leads to release of a molecule that is used to diagnose thrombotic events. What is it?

Answer 14

D-dimer