circulation II

Question 1

causes of thrombosis

Answer 1

virchow’s triad:
1 - injury to vessel wall
2 - increased coagulability
3 - decreased flow

Question 2

hemostasis

Answer 2

• normal
• blood maintained clot free
• hemorrhage stopped by sealing vessels after rupture

Question 3

thrombosis

Answer 3

• pathological
• inappropriate clotting in living person
• clot formation on uninjured endothelium or occlusion of vessels after minor injury

Question 4

thrombus

Answer 4

coagula that forms inside blood vessels or heart chambers

Question 5

clot

Answer 5

coagula outside of blood vessels or in vessels after death

Question 6

pathogenesis of thrombosis - endothelial injury

Answer 6

1 - injury/loss to endothelial cells
2 - inflammation
3 - anatomic alterations - plaques
4 - trauma/surgery
5 - endothelial dysfunction

Question 7

pathogenesis of thrombosis - abnormal blood flow

Answer 7

• non-laminar - brings platelets closer to wall, does not dilute clotting factors or bring enough anti-clotting factor
• decreased blood flow - patients confined to bed, dilated atria or vessels, venous thrombosis
• turbulence - endothelial injury and dysfunction

Question 8

pathogenesis of thrombosis - hypercoagulability

Answer 8

1 - primary (genetic)
common: factor V (G1691A), prothrombin (G20210A), (C677T) mutations, or increased factors VIII, IX, XI, or fibrinogen
rare: protein C or S, or antithrombin III deficiency
2 - secondary (acquired) - cardiac failure, tissue damage, oral contraceptives, hyperestrogenic state, disseminated cancer, increased platelets, lifestyle

Question 9

heparin-induced thrombocytopenia (HIT)

Answer 9

unfractionated heparin induces formation of antibodies against heparin-platelet factor 4

Question 10

anti phospholipid antibody syndrome

Answer 10

• antibodies bind ot plasma proteins causing endothelial damage, hypercoagulant state

Question 11

ventricular mural thrombosis

Answer 11

• caused by injury to endocardium or decreased flow following MI

Question 12

vegetations

Answer 12

• thrombosis of heart valves

- endothelial injury from bacteria, antibodies, trauma

Question 13

venous thrombosis - phlebothrombosis

Answer 13

• stasis of blood in uninflamed veins
• deep veins in calf, popliteal fossa
• firmly anchored head, loosely anchored tail
• can lead to embolism, edema

Question 14

venous thrombosis - thrombophlebitis

Answer 14

• thrombosis in inflamed veins

- can be sterile due to trauma or septic due to bacteria

Question 15

thrombosis of microcirculation - DIC

Answer 15

• disseminated intravascular coagulation

- fibrin thrombi consume platelets and coagulation proteins which leads to bleeding disorder

Question 16

outcomes of thrombosis (4)

Answer 16

1 - lysis (dissolution)
2 - organization in connective tissue
3 - propagation towards heart
4 - embolization

Question 17

five most frequent types of embolisms

Answer 17

1 - pulmonary thromboembolism
2 - systemic embolism
3 - fat embolism
4 - air embolism
5 - amniotic fluid embolism

Question 18

embolus

Answer 18

• intravascular mass that is detached and carried

- can be part of thrombus, fat, cholesterol, gas, part of a tumor, bone marrow, foreign body, amniotic fluid

Question 19

pulmonary thromboembolism

Answer 19

• most common embolism (95%)

Question 20

systemic thromboembolism

Answer 20

• origin 80% in left side heart, large part mural thrombi
• rest from aortic aneurisms, plaques, vegetations
• lodge - 75% lower extremities, 10% brain

Question 21

fat embolism

Answer 21

• origin - fractures of long bones, trauma of fat tissue, burns
• usually silent
• fat embolism syndrome in severe cases with pulmonary insufficiency, neurologic symptoms, anemia, thrombocytopenia, petechiae

Question 22

air embolism

Answer 22

• obstetric procedures, chest trauma, decompression sickness
• bends - gas bubbles out of solution to form gas emboli
• treatment - high pressure with slow decompression

Question 23

caisson disease

Answer 23

• chronic decompression syndrome

- focal necrosis (femur, humerus, tibia)

Question 24

amniotic fluid embolism

Answer 24

• infusion of amniotic fluid into maternal circulation via tear in the placenta or rupture of uterine veins during labor or immediately postpartum

Question 25

shock

Answer 25

decreased systemic perfusion of tissues

Question 26

5 types of shock

Answer 26

1 - cardiogenic - low cardiac output
2 - hypovolemic - low circulating volume
3 - septic
4 - anaphylactic
5 - neurogenic

Question 27

three stages of shock

Answer 27

1 - nonprogressive or compensated
2 - progressive but reversible
3 - irreversible