Cardiac Cycle

Question 1

Ventricular filling

Answer 1

Av valves - during the ventricular valves both of these are open(because pressure is low and when pressure in ventricles are high those things will slap shut)

SL valves are both closed because of low pressure no blood is forcing them open

Oxygenated blood during filling is coming from the lungs down through the left atrium to the left ventricle

At the same time blood from the body is deoxygenated is coming in the vena cava through the right atrium and passing to the right ventricle both of these ventricles are filling at the same time and they reach the full volume which is called end diastolic volume

Question 2

Ventricular systole

Answer 2

All valves are temporary closed at the beginning of systole and even when the sl valves open the av valves remain closed (heart murmur indicates valve problems and that’s when a little blood leaks) as the av valves shut closed it makes the first lub sound

Sl valve opens as the pressure builds up in blood and overcomes afterload

Whatever blood is ejected out of the heart in one contraction iis called stroke volume

Pressure rapidly build in the left ventricle to the point that the blood is ejected out through the semilunar valve and the aorta

At the seem time ventriclar ejects out through the pulmonary lunar semi valve and to the lungs from the right ventricular whatever gets pumped out is called stroke volume

And whatever is left over is called end systolic volume

Stroke Volume (SV) = Blood pumped out per heartbeat
Cardiac Output (CO) = Blood pumped out per minute

Question 3

Isovolumetric relaxation

Answer 3

All valves are closed because the pressure is still too high for the av valves to open, but it’s to low to keep the sl valves open also after the blood ejects into the arteries the sl valves shut closed causing the second heart sound dup