Cardiac Cycle Flashcards
When do heart valves produce a sound?
When they shut They DO NOT make a sound when they open
Name the 5 ‘events’ during the cell cycle
Passive filling
Atrial contraction (completes ventricular filling)
Isovolumetric ventricular contraction
Ventricular ejection
Isovolumetric ventricular relaxation
How full do the ventricles become during passive filling?
~80%
How to the pressures in the right side of the heart/arteries differ from the left?
The pressures (in the right ventricular and pulmonary arteries) are much lower
During passive filling the ___ valves open so venous return flows into the _______
AV
ventricles
During passive filling pressure in the atria and ventricles is ______
close to zero
What does the P wave in an ECG signal
depolarisation
What happens to the heart in-between the P wave and the QRS
Atria contracts
When atrial contraction is complete the End Diastolic Volume is roughly ____ml in resting normal adult
130
When does ventricular contraction occur (use ECG points to clarify)
Ventricular contraction stars after the QRS (signals ventricular depolarisation) in the ECG
During isovolumetric ventricular contraction, the ventricular pressure ______
rises
When the ventricular pressure exceeds the atrial pressure the ____ valves ____
AV (atrioventricular) shut *this produces the first heart sound (LUB)
During isovolumetric ventricular contraction, what valves are shut?
The aortic valve is still shut so no blood can enter or leave the ventricle The AV valves (mitral/bicuspid)
When tension rises around a closed volume this is called _____. it causes the ventricular pressure to _______
Isovolumetric contraction Rise VERY steeply
When the ventricular pressure exceeds aorta/pulmonary artery pressure the ____ valves open
Aortic/pulmonary valve *SILENT EVENT
During ventricular ejection the stroke volume (SV) is ejected by each ventricle, leaving behind the _______
End diastolic volume
During ventricular ejection the aortic pressure _____
rises
What wave in the ECG signals ventricular repolarisation
T-wave
During ventricular ejection the ventricles relax and the ventricular pressure starts to _____
fall
When the ventricular pressure falls below aortic/pulmonary pressure what happens?
aortic/pulmonary valves shut This produces the SECOND HEART SOUND (DUB)
The aortic valve closure coincides with valve vibration which produces the _____ _____ in aortic pressure curve
dicrotic notch
Closed off aortic/pulmonary valves signals the start of the ________ ________ _______
Isovolumetric ventricular relaxation
When tension falls around a closed volume this is called?
Isovolumetric relaxation
When the ventricular pressure falls below atrial pressure, AV valves ______ and the heart starts a new cycle
Open
HEART SOUNDS The first heart sound (S1) is caused by _______ and ______. It sounds like a “lub”
Closure of mitral and tricuspid valves
HEART SOUNDS S1 heralds the beginning of ______
Systole
HEART SOUNDS The second heart sound (S2) is caused by ________ and ________. It sounds like a “dub”
Closure of aortic and pulmonary valves
How many heart sounds is normal?
2 Additional heart sounds (S3 or S4) may be heard - not normal
The RED area is where you would auscultate for what valve?
Aortic
The BLUE area is where you would auscultate for what valve?
Pulmonary
The GREEN area is where you would auscultate for what valve?
Tricuspid
The PINK area is where you would auscultate for what valve?
Mitral
How does arterial pressure not fall to zero during diastole?
The heart, arteries, and veins comprise a closed system under constant pressure. (If the pressure wasn’t constant, blood would not flow.) The systolic blood pressure represents the amount of pressure exerted by blood on arteries when the heart beats; the diastolic pressure is the pressure when the heart is at rest. Since there is constant pressure in the circulatory system, diastolic pressure cannot be zero, or there would be no blood flow
When does the JVP occur?
Afer right arterial pressure waves
Point ‘a’ is _____ ______
Atrial contraction
Point ‘c’ is _____
Bulging of the tricspid valve into atrium
Point ‘v’ is _____
rise of arterial pressure during atrial filling
*release as AV valves open
