Ch 4 Pathoma - Thrombosis/Embolism Flashcards Preview

Pathology > Ch 4 Pathoma - Thrombosis/Embolism > Flashcards

Flashcards in Ch 4 Pathoma - Thrombosis/Embolism Deck (32):
1

Thrombosis

pathologic formation of an intravascular blood clot

2

Lines of Zahn

alternating layers of platelets/fibrin and RBCs characteristic of thrombosis (thrombi are also attached to vessel walls)

3

How can you tell a thrombus from a postmortem clot on autopsy

lines of zahn

4

Virchow's Triad

disruption in blood flow (turbulent or static), endothelial cell damage, hypercoaguable state

5

3 examples of disruption in normal blood flow

Immobilization, cardiac wall dysfunction (arrhythmia or MI), aneurysm

6

5 ways endothelial cells prevent thrombosis normally

Block exposure to sub endothelial collagen, produce prostacyclin (PGI2) and NO, secrete heparin-like molecules, secrete tPA, secrete thrombomodulin

7

Prostacyclin (PGI2) and NO (ways endothelial cells prevent thrombosis)

vasodilation and inhibition of platelet aggregation

8

Heparin-like molecules (ways endothelial cells prevent thrombosis)

augment antithrombin III (ATIII), which inactivates thrombin and coag factors

9

Tissue plasminogen activator (tPA) (ways endothelial cells prevent thrombosis)

converts plasminogen to plasmin which (1) cleaves fibrin and serum fibrinogen, (2) destroys coagulation factors, (3) blocks platelet aggregation

10

Thrombomodulin (ways endothelial cells prevent thrombosis)

redirects thrombin to activate protein C, which inactivates factors V and VIII

11

3 causes of endothelial damage

atherosclerosis, vasculitis, high levels of homocysteine

12

Two ways to have elevated homocysteine

vitamin B12/folate deficiency and cystathionine beta synthase (CBS) deficiency

13

How Vitamin B12/Folate deficiency --> Homocysteine buildup

folic acid (aka tetrahydrofolate, THF) circulates in serum as methyl-THF --> methyl transfered to cobalamin (B12) --> (THF can participate in synthesis of DNA precursors) --> cobalamin transfers methyl to homocysteine resulting in methionine

14

Cysthationine beta synthase deficiency

cbs converts homocysteine to cystathionine; characterized by vessel thrombosis, mental retardation, lens dislocation, and long slender fingers (also results in homocystinuria)

15

4 genetic causes for hypercoagulability

Protein C or S deficiency, Factor V Leiden, Prothrombin 20210A, ATIII deficiency

16

Protein C or S deficiency

- autosomal dominant
- normally they inactivate factors V and VIII
- increased risk for warfarin skin necrosis

17

Factor V Leiden

mutated form of factor V that lacks the cleavage site for deactivation by proteins C and S
- most common inherited cause of hypercoagulable state

18

ATIII deficiency

- ATIII inactivates thrombin and coagulation factors

19

In ATIII deficiency does PTT rise/fall/stay the same with standard heparin dosing

stays the same (heparin works by binding and activating ATIII) --> give high dose heparin to activate the limited ATIII and coumadin to maintain anticoag state (can stop high dose heparin when you pass skin-necrosis warfarin window)

20

Estrogen induces ______ production of coagulation factors (increased/decreased)

increased (oral contraceptives = increased risk for thrombus)

21

Embolism

intravascular mass that travels and occludes downstream vessels

22

5 types of emboli

thromboembolus, atherosclerotic embolus, fat embolus, gas embolus, amniotic fluid embolus

23

Embolus characterized by presence of cholesterol clefts

atherosclerotic embolus (formed by atherosclerotic plaque that dislodges)

24

Embolus associated with bone fractures

Fat embolus

25

embolus associated with dyspnea and petechiae on skin overlying the chest

fat embolus

26

embolus classically seen in decompression sickness

gas embolus (presents with joint/muscle pain = "bends" and respiratory symptoms = "chokes"

27

Cassion disease

chronic form of gas embolism characterized by multifocal ischemic necrosis of bone

28

Amniotic fluid embolus presentation

Presents with SOB, neurologic symptoms, and DIC (due to the thrombogenic nature of amniotic fluid) - during labor or delivery

29

embolus characterized by squamous cells and keratin debris

amniotic fluid embolus (both are from fetal skin)

30

Pulmonary infarction due to PE presentation (4 symptoms)

SOB, hemoptysis, pleuritic chest pain, pleural effusion

31

Systemic embolism most commonly arise in the ____ _____

left heart

32

asldkjf

lkdjfs