L20: Embolism, Ischaemia, Infarction Flashcards Preview

Cardiovascular System > L20: Embolism, Ischaemia, Infarction > Flashcards

Flashcards in L20: Embolism, Ischaemia, Infarction Deck (14):

How would you distinguish grossly between a thrombus and a thromboembolus?

Search for thrombus upstream


Where do most venous thromboemboli become trapped?

GIT, splenic, pancreatic mesenteric veins/ portal vein --> vascular bed of liver

Venous thromboemboli elsewhere --> lungs


What is a consequence of septic thromboembolism?

New foci infection


What are the possible consequences of pulmonary thromboembolism?

Doesn’t usually cause infarction due to dual blood supply
but may occlude pulmonary artery --> cor pulmonate


List other types of emboli besides thromboemboli.

Bacterial colonies/ malignant neoplastic cells/ lipid
Foreign bodies, parasites, fibrocartilage, tissue cells, agglutinated erythrocytes , gas bubbles (Nitrogen)


What is meant by the terms ischaemia, infarction and infarct?

Ischaemia= hypoxic/ anoxic injury resulting from local reduction blood flow
Infarction= process where ischaemic necrosis of local area develops
Infart= area of infarcted tissue


What are some conditions other than thrombosis, thromboembolism or embolism that can cause ischaemia?

• Congestive heart failure
• Shock
• Dehydration
• Impaired venous return to right heart (e.g. bloat)
External compression of vessels


Why is infarction more commonly referable to arterial obstruction than to venous obstruction?

Many tissues lack a collateral arterial blood supply whereas collateral venous channels may be numerous


What are the major factors that determine the prognosis for an animal that has a local reduction in blood flow?

• Availability of alternative blood supply of oxygen
• Rate of development/ degree --> sudden and acute usually causes infarction
• Size of affected vessel
• Cell vulnerability to hypoxia
• Duration of hypoxia
Oxygen content of blood


Why are infarcts less likely to develop in the lungs or liver than in other organs?

Lungs are supplied with both pulmonary and bronchial arteries
Liver receives blood from hepatic artery and portal vein


what are the brain neuron, myocardial fibre, renal proximal tube and small intestinal cells vulnerability to hypoxia?

brain neurons - 3 - 4 min
myocardial - 20 - 30 min
renal proximal - 2 hr
small intestine epic - 5 - 10 min, crypt cells 2 - 4 hr


where is coagulative necrosis caused by infarct commonly seen?

in almost all tissue excluding spinal cord and brain


where is liquefaction necrosis caused by infarct commonly seen?

brain and spinal cord


what is a saddle thromboembolism?

when a thromboembolism lodges at the site of vessel bifurcation