Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CPR Test 1 > Blood Coagulation and Fibrinolysis > Flashcards

Blood Coagulation and Fibrinolysis Flashcards

1
Q

The arrest of bleeding or prevention of hemorrhage

A

Hemostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Steps in hemostasis:

A
  1. Vascular spasm / vasoconstriction
  2. Platelet plug formation / primary hemostasis
  3. Blood coagulation / secondary hemostasis
  4. Dissolution of the fibrin clot / tertiary hemostasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Smooth muscle contraction resulting from trauma to the vessel wall is….

A

Vascular Spasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Stages of platelet plug formation:

A
  • Platelet adhesion to the damaged surface and activation
  • Platelet recruitment
  • Platelet aggregation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Platelet adhesion and role of von Willebrand factor (vWf)

  1. Platelet …….. binds to …….. – Structural changes e.g. development of pseudopods to promote platelet-platelet interactions.
  2. ………. binds to platelet receptor, …….. resulting in changes in the platelet membrane
  3. Binding also exposes ………. for binding of fibrinogen
A
  1. GpIA, collagen
  2. Von Willebrand factor, Glycoprotein IB
  3. GpIIB/IIIA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

vWf deficiency is associated with a

A
  • Defect in the formation of the platelet plug (primary hemostasis)
  • Defect in coagulation (due to low levels of factor VIII) – defect in secondary hemostasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

vWF complexes with ……..; carries it, stabilizes it and prevents its degradation.

A

Factor VIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Role of von Willebrand factor (vWF) in platelet adhesion

A

vWf acts as a bridge between specific glycoproteins (GPIb) on the surface of platelets and collagen fibers – Facilitates platelet adhesion to the vessel wall and platelet aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Immediately following the initial platelet adhesion, the platelets are activated. What are the two actions of platelets that can occur next?

A
  1. Synthesis and release of thromboxane A2

2. Release of platelet granule contents (ADP), that activate other platelets, promoting aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Binding of ADP to its receptor results in the following intracellular events

A
  • Increases intracellular Ca2+
  • Decreases intracellular cAMP levels (both of which facilitate platelet aggregation) 
  • Aggregation of platelets cannot take place without ADP stimulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Increased …… stimulates platelet cells to synthesize TXA2

A

Intracellular Calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of Thromboxane A2?

A

TXA2 induces platelet aggregation by activating other platelets. It diffuses out of the cell to enhance vasoconstriction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Platelet aggregation is mainly mediated by ……….

A

Fibrinogen. Fibrinogen binds to GPIIB/IIIA on adjacent platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Disease: A defect in Glycoprotein IIB/IIIA causes….

A

Glanzmann Thrombasthenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Steps formation of platelet plug (Primary hemostasis)

A
  1. Exposure of subendothelial collagen (INJURY)
  2. Platelet adhesion via GPIA and GPIB (via vWF) to subendothelial collagen (PLATELET ADHESION)
  3. Platelet activation, shape change and degranulation (ADP release) (SHAPE CHANGE)
  4. ADP binds to neighboring platelets to increase intracellular calcium and decrease intracellular cAMP; Increased TXA2 (GRANULE RELEASE)
  5. Platelets recruited to the site of injury (RECRUITMENT)
  6. Platelet aggregation via fibrinogen linking adjacent platelets via GPIIB/IIIA (AGGREGATION/PLUG)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the aim of blood coagulation?

A

convert soluble fibrinogen to insoluble fibrin (threads that stabilize the platelet plug). The conversion of fibrinogen to fibrin requires thrombin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is thrombin produced?

A

The formation of Thrombin occurs via 2 pathways:

1) Intrinsic pathway
2) Extrinsic pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

…….. is required for the hepatic synthesis of Prothrombin (Factor II), VII, IX, X, Proteins C and S

A

Vitamin K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the co-enzyme for y-carboxylase

A

Vitamin K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What cofactor is required for the Vitamin K dependent clotting factors, II, VII, IX, and X?

A

Calcium ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What fibrinolysis?

A

Dissolution of the fibrin clot (tertiary hemostasis)

22
Q

Which Factor and pathway is most sensitive to Vitamin K?

A

Factor VII (Extrinsic Pathway)

23
Q

Which factors are released that cause vascular spasm?

A

Endothelin and Serotonin

24
Q

What activates Phospholipase A2?

A

Calcium

25
Q

What is the function of Phospholipase A2?

A

Cleaves phospholipids to release arachidonic acid

26
Q

What is aggregated to form a soft clot?

A

Fibrin monomers are linked together by hydrogen bonds

27
Q

What is aggregated to form a hard clot?

A

Factor XIIIa (activated by thrombin) cross links with fibrin monomers via covalent bonds. Thus, converting the soft clot into a hard clot

28
Q

Lab tests for the coagulation cascade:

A

– Clotting time: Tests for integrity of the extrinsic, intrinsic and common pathways
– Prothrombin time (INR or PT): Tests for integrity of the extrinsic pathway
– Activated Partial Thromboplastin time (aPTT): Tests for integrity of the intrinsic pathway

29
Q

……. is a very sensitive indicator of vitamin K deficiency and for follow-up of patients on warfarin therapy

A

Prothrombin Time (INR or PT)

30
Q

Patients with Deep Vein Thrombosis are likely to have increased levels of….

A

Fibrin degradation products and D-dimer levels

31
Q

Which chemical mediators are released by healthy endothelium and prevent platelet aggregation?

A

PGI2 (prostacyclin) and nitric oxide

32
Q

What is the function of Prostacyclin?

A

Increases intracellular cAMP levels in platelets and inhibits platelet activation. It is a thromboxane antagonist

33
Q

Name the 2 anti-coagulant factors and their functions.

A

• Antithrombin III –
Binds to and inhibits factor Xa, thrombin (IIa) and other activated clotting factors
– Heparin (glycosaminoglycan) acts by activating this factor and preventing coagulation

• Protein C and S (also require vit K for -carboxylation) – Protein C is activated by the binding of thrombomodulin to thrombin
– Protein S is a cofactor for protein C
– Proteins C and S act together to inactivate cofactors Va and VIIIa of the coagulation cascade

34
Q 
How do the following drugs affect the coagulation cascade?
Aspirin
Heparin
Warfarin
Streptokinase
A
  • Aspirin– prevents the formation of thromboxane in platelets. Irreversible inhibitor of cyclooxygenase (COX)
  • Heparin – activates antithrombin III and inactivates thrombin
  • Warfarin (oral anticoagulant) – blocks epoxide reductase in liver and prevents the regeneration of the active form of Vitamin K. Inhibits the synthesis of the mature vitamin-K dependent clotting factors
  • Streptokinase – thrombolytic agent; plasminogen activator; converts plasminogen to plasmin enabling the dissolution of clots
35
Q

Increased Bleeding time is an indicator of….

A
  • Low platelet count
  • vWf deficiency
  • Platelet receptor defects
36
Q

Define Bleeding Time and Clotting Time.

A

Bleeding Time: time taken from the initial injury to the formation of the platelet plug

Clotting Time: Time taken for the formation of the stable fibrin

37
Q

What are the two tests for Coagulation Disorders?

A 
Prothrombin Time (PT or INR) 
Activated Partial Thromboplastin Time (aPTT)
38
Q

Prothrombin Time measures for defects in:

A

Extrinsic Pathway: Factor 3, 7, 5, 10, Prothrombin (Factor 2), Fibrinogen

39
Q

Activated Partial thromboplastin time measures defects in:

A

Intrinsic Pathway: Factor 8, 9, 11, 12,10, 5, Prothrombin, Fibrinogen

40
Q

What test is used to identify the platelet glycoprotein defects?

A

Flow cytometry

41
Q

Inherited disorders of the Intrinsic Coagulation Pathway

A

Hemophilia A and B

  • X-linked recessive
  • Clinical Features: Easy Bruising, Massive hemorrhage after trauma or surgery, Spontaneous hemorrhage
  • Hemophilia A- Factor 8 (low levels)
  • Hemophilia B- Factor 11 (low levels)
42
Q

Hemathrosis…..

A

Bleeding into joint cavity

43
Q

Platelet Count, Bleeding Time, Clotting Time, Prothrombin Time, APTT for Hemophilia A & B

A 
Platelet Count: Normal
Bleeding Time- Normal
Clotting Time- Increased
Prothrombin Time- Normal
APTT- Increased
44
Q

Von Willebrand Disease: Cause and Defect

A

Defect in platelet plug formation and instability of Factor VIII

45
Q

Von Willebrand Disease: Clinical Features

A

– Increased mucosal bleeding
– Epistaxis (Bleeding from the nose)
– Increased post-operative bleeding

46
Q

Platelet Count, Bleeding Time, Clotting Time, Prothrombin Time, APTT for Von Willebrand Disease

A

Platelet Count: Normal
Bleeding Time- Increased
Prothrombin Time- Normal
APTT- Increased

47
Q

Disease: Presents with Low Platelet Count and Increased Bleeding Time

A

Thrombocytopenia

48
Q

Disease: GpIB defect

A

Bernard Soulier Syndrome

Identified by Flow Cytometry

49
Q

Disease: GpIIB/ IIIa defect

A

Glanzmann Thrombasthenia

Identified by Flow Cytometry

50
Q

Increased Clotting time, Prothrombin Time, and APTT indicate which type of disorder?

A

Coagulation Disorder

CPR Test 1 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions