Module 8 ML-6 Flashcards
What are the two phases of the cardiac cycle
systole and diastole
What is diastole?
relaxation and ventricular filling
What is the length of diastole
longer 2/3 of time 600-800msec
What is systole
contraction, ventricular pressure (squeezing)
What is the length of systole
short 1/3 of time 200-400msec
What are the 4 period within the two phases
ventricular filling
isovolumetric contraction
ejection
Isovolumetric relaxation
What are the two parts of ventricualr filling?
passive and active
Passive filling
rapid and most filling occurs passively and rapidly
Active filling
this is shown by the P wabe and involved the atrial kick
Atrial kick
active contraction and adds 10-20% more blood to ventricle at rest
In order for filling to occur what has to happen
AV valves are open and SL valves are closed
How is EDV achieved
by both passive and active filling and the final voltume is 135 mL
What is isovolumetric contraction
ventricles contract (on 135 ml) and tension and pressure develop
What are the valved doing durin isovolumetric contraction
AV and SL valves are closed
What causes SL valves to be closed
Pressure in ventricles are less than pressure in aorta
What causes AV valves to close
Pressure in ventricles is greater than pressure in atria
What sound do we get in this contraction
the first heart sound which is “lub”
What valves are open for ejection
AV closed and SL are open due to pressure
What causes the SL valve to be open in ejection
pressure in vnetricles is greater than pressure in aorta and PA
In ejection what happens
we get stroke volume which is blood ejected from each ventricle at rest
ESV
the volume of blood remaining in the ventricle after ejection
True or False; SV is the same from both ventricles
True
Is isovolumetruc ventricular relaxation D or S
diastole
What sound do we here in isovolumetricl relaxation
“dub” which is the SL valve closing
What is the volume in isovolumetric relaxation
held constant at 65mL
What sound sound occurs in ISVR
the “dup” which is the SL valve closing
What is the differece bewteen the phases of the left and right side
timing of all events are the same but the pressure is lower on the right side
Systolic=25
Diastolic=10
Sinus Rhythm
normal cardiac excitation
- contraction sequence beginning at the SA node
Latent pacemaker
lying quiet or hidden, not active potential pacemakersW
What does the latent pacemaker include?
Av node and conducting cells
Ectopic Pacemaker
abnormal, anys site driving ventricular excitation- contraction sequence that is not the SA node
Tachycardia
HR is greater than 100 beats per minute
Bradycardia
HR is less than 60 beats per minute
Fibrillation
totally iorregular and chaotic AP propagation
-muslce like a bag of worms
-no pattern
-dangerous and fatal
Lead 1
avF
Lead 2
avL
Lead 3
avR