L18: Peturbations of Flow 2 (Thrombosis) Flashcards Preview

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Flashcards in L18: Peturbations of Flow 2 (Thrombosis) Deck (12):

What are the three major mechanisms predisposing animals to thrombosis?

Endothelial cell injury
Abnormal haemodynamics (stasis, turbulence)


How does blood turbulence predispose to thrombosis?

damage to EC and local stasis, accelerates intravascular procoagulant factors


How does blood stasis predispose to thrombosis

hypercoaulability due to increase pooling/ contact, hypoxic injury to EC


Which circumstances lead to blood hypercoagulability

preg, DIC, snakebite, pancreatic necrosis, severe tissue trauma


Describe basic events of thrombus formation

EC trauma so adopt procuagulant phenotype/ "activated" > release EDP, thromboxane etc. for recruitment > cascade results in conversion of insoluble fibrinogen into fibrin


Whats a mural thrombus?

partially protruding into lumen, not totally occlusive


lines of Zahn are what

microscopic lamination


Gross appearance of thrombus in artery or heart?

firm, pale yellow, dry, rough
chiefly platelets, fibrin
High velocity so pressure sweeps RBC away
prominent laminations
slow propagation
firm anchorage


Gross appearance of thrombus in vein?

moist, dark red, generally occlusive, larger, attachment points fragile, longer tail


What gross features would allow you to distinguish between an ante mortem venous thrombus and a post mortem red currant blood clot?

Not attached to vessel wall, gelatinous, red and white separated
Ante mortem are attached (fine tangled strands fibrin) and congestion and oedema upstream


Are venous or arterial thrombi more likely to embolise?

venous mate


How do thrombi undergo organisation? What is meant by the term recanalisation of a thrombus?

Phagocytosis by leukocytes, ingrowth EC, SMC, fibroplasts
Capillaries anastomose to allow longitudinal recanalisation