Pathophysiology of Thrombosis and Embolism Flashcards
What is normal flow of blood?
Laminar
What is meant by stasis?
Stagnation of flow
What is meant by turbulence?
Forceful unpredictable flow
What are the causes of common defects in blood flow?
Thromboembolism
Atheroma
Hyperviscosity
Spasm
External compression
Vasculitis vascular steal
What is meant by Virchow’s triad?
- Changes in the blood vessel wall
- Changes in the blood constituents
- Changes in the pattern of blood flow
What does Virchow’s triad influence?
They are the factors causing thrombosis
Give an example of a change in the vessel wall
Atheromatous coronary artery
What is the basic pathogenesis of thrombosis?
Endothelial injury
Plaque formation
Stasis or turbulent blood flow
Hypercoagulability of the blood
What are lines of Zahn on a thrombus?
Represent bands of fibrin (lighter) with entrapped white blood cells and red blood cells (darker).
What causes the adherence of platelets?
Loss of intimal cells and the exposure of collagen
What traps red blood cells in a blood clot?
Fibrin meshwork
What is responsible for the propagation of thrombosis?
Further turbulence and platelet deposition
What is the relationship between atheroma and thrombosis?
Arterial thrombosis most commonly superimposed on atheroma; Virchow’s triad
What are the possible changes in the blood constituents (Virchow’s triad) that can result in thrombosis?
Hyperviscosity, post - operative traumatic hypercoagulability
Hypercholesterolaemia?
What are the possible alterations in blood flow (Virchow’s triad) that can result in thrombosis?
Stasis - post op “economy class syndrome”
Turbulence: atheromatous plaque, aortic aneurysm