cardiac cycle Flashcards
whats the first step of the cardiac cycle?
late diastole
both sets of chambers are relaxed and ventricles fill passsivly
whats the second step of cardiac cycle?
atrial systole
atrial contraction forces a small amount of additional blood into ventricles
whats the third stage of cardiac cycle
isovolumic ventricular contraction
first phase of ventricular contraction pushes AV valves closed but does not create enough pressure to open semilunar valves
what is the fourth stage of cardiac cycle?
ventricular ejection
as ventricular pressure rises and exceeds pressure in the arteries, the semilunar valves open and blood is ejected
what is the final stage of cardiac cycle?
isovolumic ventricular relaxation
as ventricles relax, pressure in ventricles falls, blood flows back into cusps of semilunar valves and snaps them closed
what is a phonocardiogram
a chart or record of the sounds made by the heart
what are the first lines seen on a phonocardiogram
Mitral & tricuspid
valves closing
what are the second lines seen on a phonocardiogram
Stenosis of aortic/pulmonary or
Regurgitation through mitral/tricuspid
what is the third lines seen on a phonocardiogram
Aortic &
pulmonary
valves closing
whats the last continous line seen on the phonocardiogram?
Stenosis of mitral/tricuspid or
Regurgitation through aortic/pulmonary
systolic pressure
pressure your heart exerts while beating
diastolic pressure
amount of pressure in your arteries between beats
mean arterial pressure
calculates mean arterial pressure from measured systolic and diastolic blood pressure values.
end diastolic volume
volume of blood in the right and/or left ventricle at end load or filling in (diastole) or the amount of blood in the ventricles just before systole.
end systolic volume
is the volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole. ESV is the lowest volume of blood in the ventricle at any point in the cardiac cycle.
stroke volume
The amount of blood pumped by the left ventricle of the heart in one contraction
ejection fraction
measurement of the percentage of blood leaving your heart each time it contracts
what is the A wave caused by?
atrial contraction (atrial systole)
what is the C wave caused by ?
contraction of the ventricles pushes against the mitral valve which in turn increases the pressure of the atrium (ventricular systole)
whats the slow v wave caused by?
as ventricles contract, atrium starts to fill again and pressure rises (atrial diastole)
what pressure is the aorta throughout the cycle?
high
what pressure is the ventricle throughout the cycle
flops between high and low
what pressure is the atrium throughout the cycle
low
why is there a little blip in aortic pressure as blood is pushed through to the aorta?
elasticity causes a recoil
what is a healthy hearts ejection fraction?
2/3
what would a 3rd heart sound be?
the rapid fillling phase
when mitral valve opens a rush of blood comes through to the ventrice
what would a 4th heart sound be?
the acting filling phase
when atrium contracts and pushes all its blood through
