4 valves: when closed, blood cannot flow back. Held together by ____ muscles and ___ ___ ? if ruptured (as in a huge ___ ___), the valve flails and blood ____ flows ? need ___ ___ surgical correction ? blood cannot move forward.
a) Skeletal, ligamentum arteriosum, heart attack, freely, emergent, non-invasive
b) Cardiac, chordae tendineae, myocardial infarction, backward, elective, mechanical
c) Smooth, sinoatrial node, cardiac tamponade, forward, selective, immediate
d) Striated, atrioventricular node, myocardial rupture, upward, primary, invasive