BMS19-1023 Thrombosis Flashcards
Haemostasis
Arrest of blood loss from damaged vessels
What’s the basic mechanism?
Non adhesive platelets aggregate with vessel wall injury and fibrin stabilises it
Thrombosis
Formation of occlusive thrombi leading to myocardial infarction
What do endothelial cells release?
Things that dilate or constrict smooth muscle
What makes platelets adhere?
Collagen and thrombin in the ECM
Mediators
What do platelets release?
Mediators which cause constriction and further aggregation
How are platelets made able to bind thrombin?
Platelet bind to protein in collagen
Thrombin can then bind
What happens at initiation?
TF expressing cells in tissues after blood leaks out of vessels
What happens at amplification?
TF activates many factors on platelets which can convert prothrombin to thrombin
What do activated platelets do?
Turn fibrinogen to fibrin
What may be required in the pathway?
Calcium ions and phospholipids
What else does thrombin make?
Cross links for fibrin joins
How can thromobosis occur?
Fatty deposits break into the artery lumen and thromobosis occurs blocking it
What causes, treats and is a result of arteriole thrombosis?
Fatty deposits
Anti platelet drug
MI and strokes
What causes and treats venous thrombosis?
Turbulent flow
Anti-coagulants
What must you balance between?
Clot formation and haemorrhage
Haemorrhage
Blood escapes from vessels
What is the 3rd drug commonly used?
Fibrinolytic
What do antiplatelet drugs treat and how do they do this?
Arterial thrombosis and they inhibit platelet aggregation
How do fibrinogens join?
The now attached thrombin has fibrinogen receptors
What are the fibrinogen receptors called?
GP11b 111a
What do thrombins release?
Dense and alpha granules
What does thrombin do?
Activate the platelet so fibrinogen forms fibrin
What are the short names for prothrombin and thrombin?
FII and FIIa
