Hemodynamic Disorders (4) - Virchow's Triad

Question 1

Blood clot that forms in a vessel

Answer 1

Thrombus

Question 2

Blood clot that dislodges and travels in the blood stream until it reaches a vessel that it is too large to pass through

Answer 2

Embolus

Question 3

What does Virchow’s Triad represent?

Answer 3

3 things that can lead to Thrombosis (clot formation)

Question 4

What 3 things in Virchow’s Triad can lead to Thrombosis?

Answer 4

1. Endothelial Injury
2. Abnormal blood flow
3. Hyper-coagulability

Question 5

Hypercoagulability

Answer 5

Increased tendency for blood to clot

Question 6

What are some stimuli for Endothelial activation (injury)?

Answer 6

Smoking
Hypercholesterolemia
Toxins/inflammation
Abnormal blood flow **
Injury

Question 7

When the Endothelium becomes activated, it turns into a ______ state

Answer 7

PROthrombotic

Question 8

In what 2 ways does Endothelial activation become PROthrombotic?

Answer 8

1. DECREASED Thrombomodulin expression

2. INCREASED secretion of Plasminogen Activator INHIBITORS

Question 9

Describe the normal pathway and job of the endothelium expressing Thrombomodulin

Answer 9

Thrombomodulin binds to Thrombin

• That complex then activates Protein C (and S)
• Proteins C and S cleave Factors Va and VIIIa to INACTIVATE them and stop clot formation

Question 10

Describe what happens when the Endothelium is activated and it DOWNREGULATES Thrombomodulin

Answer 10

If Thrombomodulin is downregulated, it will bind less Thrombin
- That complex will then NOT activate Protein C and S
- Protein C and S then can NOT INactivate the coagulation factors Va and VIIIa
= Clot formation CONTINUES

Question 11

Describe what happens when the Endothelium is activated and it SECRETES Plasminogen Activator Inhibitors

Answer 11

Plasminogen Activator Inhibitors INHIBIT t-PA (tissue plasminogen activator)
- If t-PA is inhibited, it cannot activate plasmin
- If plasmin is not activated it will NOT degrade fibrin and the clot
= Clot formation CONTINUES

Question 12

2 types of blood flow?

Answer 12

Laminar (good)

Turbulent (bad)

Question 13

Stasis

Answer 13

Slow blood flow

Question 14

In what ways does Abnormal Blood Flow contribute to Thrombosis?

Answer 14

** Activates Endothelium

Disrupts laminar flow and prevents washout of clotting factors

Question 15

Abnormal blood flow can occur in many forms. In what type of vessels is it more likely?

Answer 15

Dilated vessels

Where vessels bifurcate (split)

Question 16

Examples of dilated vessels that lead to abnormal blood flow?

Answer 16

Aneurysm

Hemorrhoid

Question 17

Abnormal blood flow can also occur due to obstruction or inadequate heart function. List a few specific examples.

Answer 17

Obstruction due to plaque

Atrial fibrillation - inadequate blood pumping

Question 18

What type of disorders are involved with Hypercoagulability?

Answer 18

Primary and Secondary

Question 19

Primary disorders that cause Hypercoagulability are caused by?

Answer 19

Genetics

Question 20

Secondary disorders that cause Hypercoagulability are caused by?

Answer 20

Acquired

Question 21

What is the main Primary disorder of Hypercoagulability?

Answer 21

Factor V Leiden Mutation

Question 22

How is Factor V Leiden Mutation inherited?

Answer 22

Autosomal Dominant

Question 23

Describe what happens with Factor V Leiden Mutation

Answer 23

Factor V is RESISTANT to cleavage and inactivation by Protein C
= Always more likely to clot

Question 24

Primary disorders of Hypercoagulability should be considered if the patient is under what age?

Answer 24

40/50

Question 25

What are 3 Secondary disorders that cause Hypercoagulability?

Answer 25

Oral Contraceptive use
Heparin-induced Thrombocytopenia
Antiphospholipid Syndrome

Question 26

Oral contraceptive use increases synthesis of?

Answer 26

Coagulation factors

Question 27

With Heparin-induced Thrombocytopenia, what must a patient come into contact with?

Answer 27

Unfractionated Heparin

Question 28

Platelets contain alpha granules. Upon activation they release them. What is a main product that is released that is important in Heparin-induced Thrombocytopenia?

Answer 28

Platelet Factor 4 (PF4)

Question 29

What does Unfractionated Heparin bind?

Answer 29

PF4

Question 30

Once Unfractionated Heparin binds PF4 then what occurs?

Answer 30

Formation of antibodies to the complex (IgG)

Question 31

Once the IgG antibodies bind to the unfractionated heparin and PF4 complex, then what occurs?

Answer 31

The IgG antibodies bind to Fc receptors on more platelet surfaces

Question 32

Once the IgG antibodies - heparin/PF4 complex binds to Fc receptors on platelets, what are the 2 options?

Answer 32

1. Platelet activation and aggregation (clot)

2. Macrophage removal of the platelet (thrombocytopenia)

Question 33

Antibodies against plasma proteins that bind to phospholipids. The patients present with miscarriages, DVT, ect.

Answer 33

Antiphospholipid Antibody Syndrome

Question 34

White Thrombus

Answer 34

ARTERIAL blood

Contains platelets, RBCs, leukocytes

Question 35

Red Thrombus

Answer 35

VENOUS blood

Many RBCs

Question 36

4 fates of a Thrombus?

Answer 36

Propagation and continued growth
Recanalization of the vessel
Embolization
Dissolution

Question 37

For Dissolution of a Thrombus, what can be administered to speed the process if given within 6 hours of the onset?

Answer 37

t-PA - activates plasmin to degrade clot

Question 38

Disseminated Intravascular Coagulation

Answer 38

Systemic activation of thrombin and widespread thrombosis

Question 39

What can Disseminated Intravascular Coagulation lead to?

Answer 39

Severe bleeding due to depletion of the platelets being used up in all the clots forming

Question 40

Endothelium dysfunction leads to decreased?

Answer 40

NO activity

Question 41

Endothelium dysfunction causes decreased NO activity. What does this cause?

Answer 41

Endothelial activation

Question 42

Endothelial activation increases?

Answer 42

Adhesion molecules