Basic Science/Embryology/Histology Flashcards
When does vasculogenesis start
Yolk sac day 17
Which embryologic structure and arch becomes ligamentum arteriosum?
Ductus arteriosus (6th arch)
Which aortic arch do the subclavians come from?
Seventh
Which aortic arch do the common and internal carotids come from?
Third
What is a bovine arch? How frequent?
Left CCA originates from the brachiocephalic trunk - 22%
What normally inhibits platelets from aggregating and adhering to the vessel wall?
Endothelium secretes NO, prostacyclin and ADPase
What is a platelets life span
8-10 days
When vessel wall is injured and subendothelium exposed, which molecules interact with platelet surface?
tissue factor, von willebrand, collagen, fibronectin
When vessel wall is injured and subendothelium exposed, which platelet surface molecules interact with vessel wall?
a2b1, glycoprotein 1b/9, a5b1
When vessel wall is injured and subendothelium exposed to platelet surface molecule, a conformational change happens to platelets and what do they release?
ADP and thromboxane A2
What does thromboxane A2 do?
Vasoconstricts and recruits platelets to site of injury
What do GP 2b3a do?
Bridges platelets together - fibrinogen cleaved by thrombin makes fibrin and then platelet plug made by mesh of fibrin
How does aspirin work?
Irreversible COX 1 inhibitor, interrupts thromboxane A2 production. At higher doses ASA also COX 2 inhibitor and antiinflammatory
How quickly does EC ASA work? What about if you chew it?
3-4 hours, 20 min if chewed
Clopidogrel is a prodrug - what cytochrome acitivates it?
CYP 450
How does clopidogrel inhibit platelet aggregation?
Irreversibly blocks P2Y12 a key ADP receptor on platelet surface
What dose of clopidogrel do you bolus to activate it within 2 hours
300-600 mg
Which medications may interact with clopidogrel?
PPI
What does ticlopodine do?
Like clopidogrel, irreversibly binds P2Y12 ADP receptor on platelet surface. No longer available because associated with TTP, neutropenia and aplastic anemia.