Lecture 14 Haemostasis and Thrombostasis Flashcards Preview

CDL301 Cardiovascular Pharmacology > Lecture 14 Haemostasis and Thrombostasis > Flashcards

Flashcards in Lecture 14 Haemostasis and Thrombostasis Deck (85)
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1

What are the sub-classifications of bleeding

Primary and secondary haemostasis

2

What are the sub-classifications of clotting

Arterial and venous thrombosis

3

What three fractions are isolated from fresh whole blood following donation

Red blood cells platelets and plasma

4

How long can red blood cells be kept and used for after donation

35 days

5

How long can platelets be kept and used for after donation

5-7 days

6

How long can plasma be kept and used for after donation

Can be frozen and stored for quite some time before use

7

How can fresh frozen plasma be further divided

Plasma can be separated into the individual clotting factors

8

What is the first response to bleeding

Localised vasoconstriction

9

What are the two components to the clotting system

Primary haemostasis – platelet activation and adhesion. Secondary haemostasis – activation of the coagulation cascade

10

What is the role of the coagulation cascade

To produce fibrin that fixes the cells together

11

What are the two causes of platelet bleeding disorders

Reduced platelet numbers (thrombocytopenia) or impaired platelet function that is either inherited or acquired

12

How are patients with platelet bleeding disorders treated

Platelet transfusions

13

How to platelets bind to collagen in the endothelium during clotting

Via the binding of von Willebrand factor

14

What is the inheritance pattern of von Willebrand disease

Autosomal dominant

15

Von Willebrand disease is the most common inherited bleeding disorder with as many as 10% of the population having reduced vWF levels T or F

F – whilst it is the most common inherited bleeding disorder its 1% of the population who have reduced vWF levels

16

Von Willebrand disease is a milder bleeding disorder to haemophilia T or F

T

17

What are the main symptoms of von Willebrand disease

Bruising cuts mennohagia epistaxis (nose bleeds) and bleeding of the gums

18

What are the two approaches in the treatment of von Willebrand disease

Desmopressin to stimulate endothelial cell degranulation of the Weibel-Palade bodies that contain vWF. Alternatively intermediate purity/plasma-derived factor VIII is given which contains vWF

19

What is the name of the granules that contain vWF in the endothelial cells

Weibel-Palade bodies

20

What factor is activated first in the imitation of secondary haemostasis

Tissue factor or clotting factor VIIa

21

What is the main activator of the coagulation cascade in humans

Clotting factor VIIa

22

How is factor VIIa activated during vessel injury

Injury to the vessel exposes FVIIa which is underneath the vessel

23

What are the two effects of activating factor VIIa

FVIIa both directly and indirectly leads to the conversion of factor X to factor Xa. It directly stimulates this conversion but also acts via triggering the conversion of factor IX to IXa which then stimulates factor X conversion

24

Which pathway of factor Xa production is more efficient

The indirect pathway

25

What is the role of factor Xa in the coagulation cascade

Factor Xa activates the conversion of factor II to factor IIa. Factor IIa is also known as thrombin and is the enzyme responsible for catalysing the conversion of fibrinogen to fibrin

26

Below is an outline of the coagulation cascade fill in the missing clotting factors

See completed diagram below

27

What is the inheritance pattern of haemophilia A and B

X-linked

28

Haemophilia A and B have distinct clinical features T or F

F – they have identical clinical features

29

Which clotting factor is deficient in haemophilia A

FVIII

30

Which clotting factor is deficient in haemophilia V

FIX