The cardiac cycle Flashcards
what is systole
when it is in a contractile state
what is diastole
when in a relaxed state
three stages of the cycle
atrial systole: contraction of the atria
ventricular systole: contraction of the ventricles.
diastole: relaxation of both the atria and the ventricles
during atrial systole
atrioventricular valves open so that blood can enter the ventricles
during ventricular systole
atrioventricular valves shut
semilunar valves open
the blood leaves the heart through the great arteries
which are the atrioventricular valves
they connect the atria to the ventricles
tricuspid valve on the right
mitral (or bicuspid) valve on the left
which are the semilunar valves
lie in the arterial outlets, connecting ventricles to their associated arteries
pulmonary valve lies in the pulmonary outlet on the right
the aortic valve lies in the aortic outlet on the left
two cardiac volumes
ventricular end-systolic volume
ventricular end-diastolic volume
ventricular end-systolic volume
the volume of blood in the ventricle at the end of the systolic phase
ventricular end-diastolic volume
the volume of blood in the ventricle eat the end of the diastolic phase
stroke volume
volume of blood that is ejected from the heart in one cardiac cycle
how to calculate stroke volume
stroke volume (mL) = left ventricular end-diastolic volume (mL) - left ventricualr end-systolic volume (mL)
cardiac output
total volume of blood that is pumped through the heart in a minute
how to calculate cardiac output
cardiac output (mL/min) = stroke volume (mL) x heart rate (beats per minute)
ejection fraction
this demonstrates the percentage of blood the heart receives that is ejected during systole
