Cardiac Cycle Flashcards
name the 4 heart valves
Right AV tricuspid valve
Left AV mitral valve
Aortic Valve
Pulmonary valve
there is sound made when the heart valves are open - True or False
False
what triggers the cardiac cycle
orderly depolarisation
what is the cardiac cycle
ALL events that occur from beginning of 1 heart beat to the beginning of the next
what is longer diastole or systole
diastole
define diastole
heart ventricles are relaxed and fill with blood
define systole
heart ventricles contract and pump blood inot the aorta (LV) and pulmonary artery (RV)
5 order of events in the cardiac cycle
- passive filling
- atrial contraction
- Isovolumetric ventricular contraction
- Ventricular ejection
- Isovolumetric ventricular relaxation
what is the pressure in the atria and ventricles during passive filling
0
what happens during passive filling
AV valve opens allowing venous return flow into ventricles
what is the aortic pressure and state of the aorta during passive filling
pressure = 80 mmHg
aortic valve is closed
how full are the ventricles after passive filling
80%
during passive filling is pressure in the right ventricles and pulmonary artery high or low
LOW
lower than left
what happens during atrial contraction
20% of ventricular filling
atria contracts between P wave and QRS complex
what is competed after atria contraction
End diastolic volume (130 ml at rest)
what happens during the isovolumetric ventricular contraction
ventricular pressure rises
when pressure exceeds atrial pressure AV valve shuts
aortic valve is shut so pressure and tension rise
at what stage is the first heart sound heard - LUBB
isovolumetric ventricular contraction when AV valve (tricuspid and mitral) closes
beginning of systole
when does ventricular ejection occur
when ventricular pressure exceeds aortic/pulmonary artery pressure
SV leaves end systolic volume
aortic pressure rises
when is the second heart sound heart - DUBB
when pressure in ventricles s less than aortic/pulmoanry artery pressure and the aortic/pulmonary valves close
where can valve vibration be seen
diortic notch in aortic pressure curve
what is isovolumetric ventricular relaxation
closure of aortic/pulmonary artery valves = begins relaxation
ventricles = closed box
tension falls around closed volume
when does the AV valves open
when ventricular pressure falls below atrial pressure
where can the mitral valve be auscultated
mid clavicular line
5th intercostal space
apex of lung
where can the tricuspid valve be auscultated
left border of sternum
4th intercostal space
