The cardiac cycle Flashcards
The heart beats around…
70 times a minute.
The cardiac cycle the sequence of…
events which make up one heartbeat.
Atrial systole is a stage when…
the heart is filled with blood and the atrial walls contracts.
As the atrial walls contract…
blood flows from the atrium into ventricles.
The backflow in the atrium is prevented by…
closure of the valves in the veins.
The pressure in the atrium during contraction is not…
very great, as the walls are thin. But big enough to force the blood through atrioventricular valves.
Systole is…
contraction.
Diastole is…
relaxation.
Ventricular systole starts…
0.1 second after atrial systole and both ventricles contract.
During ventricular systole, the atrioventricular valves are…
pushed and shut by the pressurised blood in ventricles. The semilunar valves in the aorta and pulmonary artery are open.
The blood during ventricular systole flows from…
the ventricles into the arteries.
Ventricular diastole starts when…
muscle relaxes and the pressure in ventricles drops.
As the pressure drops in ventricular diastole drops…
the semilunar valves shut.
As the whole heart relaxes, blood flows…
into the two atria.
Cardiac muscle is…
myogenic, so it naturally contracts and relaxes(does not need impulses from a nerve).
