Pathology - Thrombi And Emboli Flashcards
What is thrombosis?
Mass of blood constituents (mostly platelets) forming in vessels
What is an emboli?
Fragments of a thrombus which lodge in smaller BV = occlusion of vessel
How is a thrombus formed?
1.Endothelial damage causing vasospasm (BV smaller in middle)
2. Primary platelet plug -VWF binds to exposed collagen and platelets bind to this
3. Coagulation cascade
What can DVT cause?
Pulmonary embolism
What influences thrombosis?
Virchows triad
What is virchows triad?
Change in vessel wall (endothelial damage - trauma, surgery, MI, smoking)
Change in blood constituents (hypercoagubility - sepsis, atherosclerosis, malignancy, contraceptives)
Change in blood flow (decreased BF - AF, immobility)
What are the 2 types of thrombosis?
Arterial
Venous
How is an arterial thrombosis formed?
What can it cause?
Treatment for it?
Symptoms?
Atherogenesis
MI (IHD), Ischemic stroke, peripheral vascular disease
Anti platelets (aspirin)
Cold + pale, loss of pulse
How is an venous thrombosis formed?
What can it cause?
Treatment for it?
Symptoms?
Venous stasis (DVT)
Pulmonary embolism
Anti coagulation (DOACs, warfarin)
Tender, swollen, red
What are the 3 results of a thrombus?
Resolution - degrades, normal
Organization - leaves behind scar tissue
Embolism- fragments of thrombi break off & lodge In distal circulation
Emboli can be arterial by lodging in …. Circulation
Eg?
Systemic circulation (left side)
AF thrombus embolises and lodges in carotid artery = ischemic stroke
Emboli can be venous by lodging in …. Circulation
Eg?
Pulmonary circulation (right side)
DVT thrombus embolises and lodges in pulmonary artery = pulmonary embolism
2 reasons why clots are rare?
- Laminar flow - cells travel in centre of vessels and don’t touch sides
- Endothelial cells living vessels are not ‘sticky’ when healthy
