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Term 3: Immunology/Pathology > Hemodynamics > Flashcards

Flashcards in Hemodynamics Deck (53):
1

What are the 5 factors that can lead to Edema?

1. Increased hydrostatic pressure
2. Decreased oncotic pressure
3. Lymphatic obstruction
4. Sodium (water) retention
5. Inflammation

2

How does heart failure lead to edema?

-Increased capillary hydrostatic pressure

-Decreased renal blood flow triggers RAAAs
=retention of Na+ and water, increasing blood volume

3

What is lymphedema?

-obstruction of the lymphatics, leading to edema

4

What is hyperemia?

-increased arterial blood flow to an area

-seen with edema

5

What is congestion?

-decreased venous flow from an area

-seen with edema

6

What is a hematoma?

a mass-like collection of blood

7

What chemicals produced by normal vascular endothelium have antiplatelet effects?

-PGI2

-NO

8

What chemicals produced by normal vascular endothelium have anticoagulant effects?

Heparin-like molecules

9

What chemicals produced by normal vascular endothelium have fibrinolytic effects?

Tissue-type plasminogen activator (t-PA)

10

What secretes tissue factor (III)?

Damaged vascular endothelium

11

What does Von Willebrand factor do?

aids in platelet adhesion to a wound

12

What does Tissue factor do?

Triggers the coagulation cascade

13

What do inhibitors of plasminogen activator do?

inhibit fibrinolysis

14

What factors prevent clotting/platelet aggregation?

-Prostacyclin (PGI2)

-NO

-ADPase

-Heparin-like molecules

-thrombomodulin

-Proteins C & S

**-t-PA (increases fibrinolysis)

15

What is contained within the alpha granules of platelets?

-P-selectin

-Fibrinogen

-fibronectin

-V & VIII

16

What is contained within delta granules of platelets?

-ADP & ATP

-Ca2+

-5-HT

-Epinephrine

-Histamine

17

What happens to platelets after a vascular injury?

-Contact collagen and adhesive vWF

-Adhesion and shape change

-secretion from granules

-Aggregation

18

What mediates platelet adhesion?

von Willebrand Factor (vWF)

19

What happens and what is the purpose of platelet shape change?

-platelets rapidly change from smooth discs to spikey things

-Alterations in glycoprotein increase affinity for fibrinogen

-Platelet surface increases negatively charged phospholipids which bind calcium and enhances coagulation

20

What does thromboxane A2 do in clotting?

-along with ADP, amplifies platelet aggregation = primary hemostatic plug

-vasoconstriction

21

What factor initiates the extrinsic hemostatic pathway?

Intrinsic factor (III)

22

What factor initiates the intrinsic hemostatic pathway?

XII

23

What happens when thrombin encounters normal endothelium?

-has anticoagulant effects

-changes from procoagulant to anticoagulant to prevent clotting from extending beyond site of vascular injury

24

What does plasmin do?

-breaks down fibrin

-interferes with fibrin's polymerization

25

Why does a Factor XII deficiency lead to problems with overclotting?

-Factor XII pathway catabolyzes plasminogen into plasmin

-plasmin is needed to break down clots

26

What activates plasmin?

-Factor XII

-tissue plasminogen activator (t-PA)

27

What is thrombosis?

pathologic clotting of blood

28

What are factors that lead to thrombosis (Virchow's Triad)?

-endothelial injury

-abnormal flow (turbulence or stasis)

-Hypercoagulability

29

How does stasis and turbulence lead to thrombosis?

-Promote endothelial activation and enhance procoagulant activity and leukocyte adhesion

-Disrupt laminar flow and bring platelets into contact with the endothelium

-Prevent washout and dilution of activated clotting factors

30

What is hypercoagulability?

-Loosely defined as any alteration of the coagulation pathways that predisposes to thrombosis

-Can be divided into:
Primary (genetic)
Secondary (acquired)

31

What is the most common cause of primary hypercoagulability?

point mutations in factor V gene (Leiden mutation)

-leads to inactivation of protein C and loss of an important antithrombotic pathway

32

What is Heparin-induced Thrombocytopenia Syndrome?

-HIT occurs following the administration of unfractionated heparin

-Can induce the appearance of antibodies that recognize the complexes of heparin and platelet activating factor 4 on the surface of platelets

-Binding of these antibodies to platelets results in their activation, aggregation, and consumption (hence the term thrombocytopenia)

-These changes can lead to a prothrombotic state

33

How do we prevent heparin-induced thrombocytopenia?

use low molecular weight heparin

34

What is Antiphospholipid Antibody syndrome?

-mechanism is unclear, but think about necessity of negative phospholipid membrane in platelets

-Clinically includes recurrent thromboses, repeated miscarriages, cardiac valve vegetations, and thrombocytopenia

**Antibodies in this disease can give a false positive serologic test for syphilis

35

What is embolization?

-when a thrombus breaks off and goes elsewhere

36

How does liver failure lead to edema?

-lower amount of albumin produced

-decreased venous oncotic pressure

-less fluid reabsorbed into veins from interstitium

37

What is Anasarca?

Generalized whole body edema

38

What results in Nutmeg liver?

-Chronic congestion of the liver

39

What are the three types of blood in the skin, from smallest to largest?

-Petechiae

-Purpura

-Ecchymosis

40

At what point does platelet aggregation become irreversible?

When fibrinogen is laid down and converted to fibrin

41

What is a Leiden mutation?

-Mutation in factor V

-Inactivation of protein C, thus loss of an important antithrombotic pathway

42

What is thrombocytopenia?

Decreased platelet count

43

What is a saddle embolus?

-an embolus that straddles the bifurcation of the main pulmonary artery

-cause of sudden death

44

What is a paradoxical embolus?

-a clot from venous circulation ends up in arterial circulation through a shunt in the heart

45

What is a Fat embolus?

-A fat globule travels to the lungs

-usually from a bone fracture

46

What is an infarction?

An area of coagulative necrosis as a result of ischemia from decreased blood flow

47

What is a red infarct?

-hemorrhagic

-caused by venous obstruction and occur in organs with double blood flow

*look at notes to understand this

48

What is a white/pale infarct?

-an infarct caused by arterial occlusion

49

What causes septic shock?

-vasodilation due to endotoxins

50

What are the clinical stages of shock?

1. Primary = compensated

2. Progressive = lactic acidosis, renal failure

3. Irreversible = severe organ damage

51

What is contraction band necrosis?

-occurs in heart coagulative necrosis

-flat, spindle shaped nuclei

-cells have contracted down

52

What is acute tubular necrosis of the kidneys?

-coagulative necrosis of proximal tubules

-PT cells have lost nuclei

53

What is diffuse alveolar damage?

-fibrin seals off alveoli after bleeding into lung

-occurs in settings of shock or breathing smoke in a fire