CV system Flashcards
t/f: the main drop in pressure occurs in the arteries
false. it occurs in the arterioles
t/f: contributing factors to BP are ANS, cardiac output, and peripheral vascular resistance
true
cardiac output
volume of blood pumped by the heart in 1 minute (5 L/min)
t/f: altering heart rate will alter chronotropy
true
t/f: altering stroke volume will alter inotropy
true
altering chronotropy and inotropy will alter cardiac output
true
preload
initial stretching of myocardium before contraction
afterload
force of heart during contraction
frank-starling mechanism
increasing the stretch increases the contractility
laplace’s law
increase stretch will increase the tension
normal ejection fraction is
55-75%
formula for ejection fraction
sv/edvv
t/f: nitric oxide and prostacyclin cause vasoconstriction
false. they cause vasodilaton
t/f: thrombozane and endothelins cause vasodilation
false. they cause vasoconstriction
t/f: nitric oxide is formed by an enzyme (NOS) that is activated by Ca ions
true
nitric oxide mechanism
- nitric oxide diffuse between endothelial cells
- activate guanylyl cyclase
- increase cGMP
- activate protein kinase G (by phosphorylation)
- vasodilation
t/f: the RAAS system modulates vasoconstriction, causing increase BP and hypertension
true
t/f: treatments for hypertension can target the RAAS system
true
t/f: resting membrane potential of ventricles is around -85 to -90 mV
true
t/f: the main ions involved in action potentials are sodium, potassium, and calcium
true
t/f: during contraction, L-type sodium channels open
false. L-type calcium
t/f: digitalis is a cardiac glycoside that reversibly inhibits the na-k atpase pump
true
t/f: digitalis will cause decreased contractility
false. it will increase contractions (by increasing ca ions in the myocyte)
t/f: the SA node has a higher resting membrane potential
true (so easier to stimulate)
