Physiology I Final lab.csv Flashcards
What does S1 represent?
closure of the AV valve
What does S2 represent?
closure of the semi-lunar valves
When does S1 begin?
at onset of ventricular systole
What combined noises do you hear?
mitral (bicuspid) and tricuspid valves. Lub
When does S2 begin?
onset of ventricular diastole.
What combined noises do you hear?
aortic and pulmonary semilunar outflow valves. сdubо
What is S3?
sometimes heard during ventricular filling
What is S4?
sometimes heard during atrial ejection
Where will loudest sounds be heard? (anatomical placement)
between intercostal spaces
Where is the aortic valve best heard?
in 2nd intercostal space to the immediate right of sternum
Where is pulmonary valve best heard?
2nd intercostal space to the immediate left of sternum
Where is the tricuspid valve best heard?
5th intercostal space to immediate left of sternum. (sometimes heard best immediate right of sternum)
Where is the mitral valve best heard?
5th intercostal space on mid-clavicular line
What patient position might assist in hearing S1 and mitral valve better?
flex forward and to left while twisting a bit to the right
What is the logical sweep pattern for ausultating?
start with aortic ? pulmonary ? tricuspid ? mitral. APTM
Which side of the patient should you position yourself?
to the patients left (not between their legs!!!)
What does the cardiac cycle represent?
a display of all the mechanical, hemodynamic, acoustical and electrical events that occur in the heart during one beat.
What are the 5 composite-assembled tracings?
aortic pressure, ventricular pressure, ventricular volume, atrial pressure, phonocardiogram, ecg
What is the most critical aspect in understanding the cardiac cycle?
relative timing of events
What 4 sources did we gather information from during lab?
ECG, phonocardiogram, peripheral pulse, and stroke volume.
What must happen to the heart before the left and right ventricle can contract and eject blood?
heart must first be depolarized (or electrically excited)
What does the QRS complex represent?
ventricular depolarization
What 3 ways can you dtermine HR (w/out using biopac)?
1) measure the distance in time b/t any successive R waves, by counting boxes (each box =0.04 sec) then divide that number into 60. 2) find R wave that falls on a line on the grid.. count over 4 seconds (25 small boxes).. then count number of beats in that segment. Then multiply by 15. 3) Find R wave and count larger boxes (0.2 sec) until next R wave. With each line count down 300, 150, 100, 75, 60, 50 etc..
What is the first method dependent on?
finding a representitive beat
What makes #2 method reliable?
the longer the period of time considered the better the value.
Which heart sound is recorded on the phonocardiogram?
first heart sound (S1) and second heart sound (S2).
What makes S1 difficult to see/Hear?
S4 because it runs into S1.
What might a rapid heart rate cause to happen?
S1 run into S2.
Which sound is stronger? S1 or S2?
S1
What does the time between the onset of the QRS complex and S1 represent?
Lag between excitation and mechanical action
How long does it last?
About 0.04 seconds.
What is well underway when ventricular excitation is happening?
S1
How do you measure VCT?
S2-S1 = VCT
What is VCT better known as?
systole
What is VRT?
ventricular relaxation time – diastole
How can you measure VRT?
measuring distances between onset of S2 and the next S1.
In a resting heart, which is shorter, VRT or VCT?
VCT is shorter than VRT.
At what heart rate do VRT and Vct become equal?
90 bpm.
What does exercise shorten?
Diastole
What is the average delay between the opening of the AV and the peripheral pulse?
~0.13 seconds.
What does the peripheral pulse lack?
Dicrotic arch
Where does the AV fall along the graph when counting backwards from PP?
The deepest valley of S1
What does the onset of the aortic pulse correspond with?
Beginning of ejection phase of cycle.
When does ejection end?
Appearance of S2
What is LVET?
Deepest valley of S1- onset of S2
What does the dicrotic notch appear as?
Incisura/dip on downward slope of pressure curve.
How can you crudely estimate LVET?
Measuring from onset of pulse to notch.
What is the IVCT?
Short amount of time it takes for the ventricles to build up pressure prior to ejection.
What is the formula for IVCT?
VCT = IVCT+LVET
What is CO?
CO = HR X SV
What does voltage begin at for EKGs?
135 mV.
P-wave ?
Atrial depolarization. 0.06-0.12 sec
Q wave?
Ventricular septal activation.
R wave
Vent depolar to Apex.
S wave
Vent depolar back to base
T wave
Vent repolar. 0.12 - 0.20 sec.
PR segment
End of p wave to start of Q.
PR interval
Approx 0.10 - 0.16 sec
QRS complex.
Approx 0.6 - 0.10 sec.
ST segment
0.8 - 0.16 sec
ST interval
End of S wave to end of T wave
QT interval.
0.26 - 0.48 sec
Isoelectric line
Best seen before P wave or after T wave.
What does a long PR segment suggest?
AV electrical block.
What is einthovens triangle?
Leads 1,2,3. In frontal plane. Heart at center. 0 mV. Triaxial display.
Which are augmented limb leads?
aVL, aVR, aVF.
What is the electrical axis?
Net electrical direction of depolarization of ventricles.
What does the normal QRS vector point to?
Down and to left. 60 degrees. Normal range = -30 - +105.
What is QRS vector a product of?
Ventricular muscle mass, and anatomic position of heart.
Which way does the axis move on inhalation?
Right shift.
In regards to hypertrophy, which way does the axis move?
Towards hypertrophy. Away from damage.
Which axis deviation with aortic stenosis?
Left
Which axis deviation with left ventricular infarction?
Right.
What is pulse pressure?
SBP - DBP.
What is MAP?
(PP/3) + DBP. Normally Bout 93
What is the initial reaction of BP after standing with the PMBPI test?
Prompt reduction. By carotid and aortic baros.
What does the PMBPI arterial BP drop result in?
Rapid compensatory changes that increase cardiac output and increase peripheral resistance. To bring BP back to normal.
Phase 1 of valsalva?
Sudden transient increase in BP due to intrathoracic pressure
Phase 2 valsalva?
Abrupt decline BP. Positive intrathoracic pressure stops venous return and cardiac output. Drop in arterial baro leads to rise in peripheral resistance and tachy. Almost no pulse
Phase 3 valsalva?
Stop bearing down. Intrathoracic pressure drops suddenly restoring venous and CO. BP rises quickly.
Phase 4 valsalva
Large CO. BP overshoot. Huge SV. Reflex Brady.
What is VO2?
Oxygen consumption. HR x SV x A-V O2 difference.
How do you determine maximum hr?
220-age.
How do you determine ideal exercise hr?
Resting HR + [.6 (max hr - resting hr)
Example
220-28 = 192.
64 + [.6(192-64)] = 140
