Cardiac cycle

Question 1

cardiac cycle

Answer 1

all events that occur form the begginign of one heart beat to the beginning of the next

Question 2

passive filling

Answer 2

Pressure in atria and ventricles close to zero

AV valves open so venous return flows into the ventricles

Aortic pressure ~ 80 mmHg, and aortic valve is closed

Similar events happen in the right side of the heart, but the pressures (right ventricular and pulmonary artery) are much lower

Ventricles become ~ 80% full by passive filling

Question 3

atrial contraction

Question 4

what signals atrial contraction in ECG

Answer 4

P wave

Question 5

when does the atria contract

Answer 5

between the p wave and qrs

Question 6

what completes the end diastolic volume

Answer 6

ATRIAL CONTRACTION

Question 7

isovolumetric ventricular contraction

Answer 7

av valve shut so no blood can enter or leave the ventricle and tension rises around a closed volume

Question 8

when does ventricular contraction strat

Answer 8

after the qrs

Question 9

what produces the first heart sound

Answer 9

closing of av valves

Question 10

ventricular ejection

Answer 10

When the ventricular pressure exceeds aorta/pulmonary artery pressure

Aortic/pulmonary valve open
ventricles relax and so the valves shut due to pressure falling

Question 11

what signals ventricular repolarisation

Answer 11

t wave

Question 12

what produces second heart sound

Answer 12

closure of aortic/ pulmonary valve

Question 13

Isovolumetric Ventricular relaxation

Answer 13

Closure of aortic/and pulmonary valves signals the start of the isovolumetric ventricular relaxation

Ventricle is again a closed box, as the AV valve is shut

The tension falls around a closed volume “Isovolumetric Relaxation”

When the ventricular pressure falls below atrial pressure, AV valves open

Question 14

what does the first heart sound herald

Answer 14

beginnign of systole

Question 15

what does s2 herald

Answer 15

beginning of diastole

Question 16

JVP

Answer 16

indirect measure of pressure in right atrium

Question 17

when is s3 heaed

Answer 17

early diastolic immediately after s2

Question 18

what might an s3 be assoc with in cardiac failure

Answer 18

Commonly left ventricular systolic dysfunction

Question 19

where are s3s best heard

Answer 19

apex

Question 20

When is an S4 heart sound heard

Answer 20

Late diastolic shortly before S1

Question 21

when are the av valves open

Answer 21

during atrial contraction and ventricular systole

Question 22

when do the av valves shut

Answer 22

when pressure in the ventricles exceeds pressure in the atria; ventricular contraction

Question 23

when do the semilumar valves open

Answer 23

ventricular contraction

Question 24

when do the semilunar valves shut

Answer 24

when pressure in atria exceeds pressure in ventricles; ventricular diastole

Question 25

preload

Answer 25

ventricular wall stress at the end of diastole

Question 26

what can affect preload

Answer 26

dilated cardiomyopathy as ventricles are dilated and stretchy

Question 27

what can decrease preload

Answer 27

ventricular cardiomyopathy as the ventricles are stiffened

Question 28

when might a fourth heart sound be heart

Answer 28

in ventricular hypertrophy due the stiffened wall making a vibration noise when bllod is flowed in