Unit 1.5 - Thrombosis

Question 1

The three causes of thrombosis (Virchow’s triad) are:

Answer 1

1. endothelial injury
2. alterations in blood flow
3. hypercoagulability

Question 2

What are the consequences of increased vascular permeability?

Answer 2

edema

Question 3

Is it more likely that the right or the left auricle should be larger in a dead animal?

Answer 3

animals often die in systole and the right auricle is larger

Question 4

A lightish-tan coloration to a muscle is indication of:

Answer 4

ischemia or reduced blood flow (start of necrosis)

Question 5

Abnormal endothelial surface or lumen configuations such as aneurysms will cause:

Answer 5

turbulence in blood flow, eddies

Question 6

What issue is frequently associated with cardiac disease?

Answer 6

thrombosis

Question 7

Local stasis and viscosity of the blood are especially significant in causing thrombi in the:

Answer 7

veins

Question 8

DIC

Answer 8

disseminated intravascular coagulation

Question 9

Loss of protein in glomerular renal disease and protein losing GI disease results in:

Answer 9

decreased plasma osmotic pressure, edema

Question 10

Hypercoagulability may be associated with the following: (4)

Answer 10

1. enhanced platelet activity
2. Increased activation of clotting factors
3. Loss of anti-thrombin III
4. metabolic abnormalities

Question 11

results in considerable shrinking of the loose fibrinous zones of the thrombus and may even partially reopen occluded vessels along one side

Answer 11

retraction and fibrinolysis

Question 12

How does retraction and fibrinolysis work?

Answer 12

plasmin delivered by the flowing blood immediately begins to lyse the fibrin on the exterior of the thrombus

Question 13

How does central softening work?

Answer 13

platelets and entrapped leukocytes release lysosomal enzymes which break down the fibrin net, and macrophages and neutrophils phagocytose the debris

Question 14

Which type of thrombus takes less time to organize: bland or septic?

Answer 14

bland

Question 15

What’s the problem with organizing a thrombus?

Answer 15

once the scar is formed, it leaves the area susceptible to another thrombus in the future

Question 16

When will recanalization take place?

Answer 16

mostly in organizing thrombi that completely occlude a vessel lumen

Question 17

What suggests a central softening on histology?

Answer 17

a focus with blood and bright yellow pigment

Question 18

What causes the bright yellow pigment associated with central softening?

Answer 18

bilirubin

Question 19

If the right heart does not keep up with venous return, what is the consequence?

Answer 19

chronic passive congestion of the liver, potentially ascites

Question 20

What are the four steps in the resolution of a thrombus?

Answer 20

retraction and fibrinolysis, central softening, organization, recanalization

Question 21

What is one of the consequences of increased hydrostatic pressure exerted on the lungs?

Answer 21

pulmonary edema

Question 22

Emboli derived from a thrombus

Answer 22

thromboemboli