Download Measurement of Blood Pressure

Cardiovascular Lab
• In this exercise, students will be introduced to
the common methods of
▫ Measuring blood pressure
▫ Listening to the major heart sounds
▫ Using a photoelectric pulse transducer to monitor
pulse rate and pulse pressure while performing
the Valsalva maneuver.
Introductory Notes
• Systolic Pressure: pressure exerted by the blood against the
arterial walls during ventricular systole (normal ≈ 120 mmHg)
• Dicrotic Notch: due to the brief backflow of blood through the
elastic arteries which closes the semilunar valves during ventricular
diastole
• Diastolic Pressure: pressure exerted by the blood against the
arterial walls during ventricular diastole (normal ≈ 80 mmHg)
Introductory Notes
• Pulse Pressure: difference between Systolic Pressure and Diastolic Pressure
(SP - DP) (normal ≈ 40 mmHg: 120 mmHg - 80 mmHg)
• Mean arterial pressure (MAP) = “average” pressure within the arteries
MAP = Diastolic Pressure + 1/3 (Pulse Pressure)
• The equation reflects the fact that the heart spends more time in diastole during
the cardiac cycle; therefore, not merely an average between SP and DP.
• Ex: If BP is recorded as 120mmHg/80mmHg
MAP
MAP
MAP
MAP
MAP
=
=
=
=
=
DP + 1/3 (SP – DP)
80 + 1/3 (120 – 80)
80 + 1/3 (40)
80 + 13.33
93.33 mmHg
Experimental Procedures
Pulse Rate: Use your second and third fingers to palpate
the radial artery of your laboratory partner. Repeat the
same procedure while palpating the carotid artery.
• Determine the radial pulse rate of your laboratory
partner under the following conditions:
1) After your partner has rested 5 minutes in a
supine position.
2) Immediately after your partner assumes a sitting
position.
3) Immediately after your partner assumes a
standing position.
Introductory Notes
• Heart Sounds
▫ 1st heart sound: closure of AV valves
▫ 2nd heart sound: closure of SL valves
• Murmur: an abnormal heart sound associated
with valvular insufficiency, and/or narrowing of
the valvular opening
Auscultation of Heart Sounds
Experimental Procedures
Auscultation of Heart Sounds: Clean the
earpieces of the stethoscope with an alcohol swab
before and after use.
1) Distinguish between the two major heart sounds
(“lubb-dupp”).
2) Listen for sounds created by all four valves and
compare each.
3) Measure the radial pulse and apical pulse
simultaneously, to determine if a “pulse deficit”
exists.
Measurement of Blood Pressure
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Experimental Procedures
Measurement of Blood Pressure: Obtain a sphygmomanometer
and test to make sure the bulb, valve, and gauge are all functioning
properly.
• Determine the blood pressure of your subject under the following
conditions:
1) After your partner has rested 2 minutes in a sitting position.
2) After your partner has rested 2 minutes in a supine position.
3) After your partner has rested 2 minutes in a standing position.
4) Immediately after your partner has exercised 5 minutes and
assumes a sitting position.
• From the “sitting position” data above, calculate the mean arterial
pressure (MAP) and record your finding.
Experimental Procedures
Plethysmography: study of blood volume change within an
organ/tissue by using volume displacement techniques
• Connect the pulse transducer to Channel 1 on the BioPac acquisition
box and click on the “Pulse” folder on your desktop.
• Record their pulse for 10 seconds and calculate the resting pulse rate.
• With your partner standing, record their pulse for 10 seconds and
calculate the pulse rate. Compare the pulse rates and pulse recording
amplitudes of the “sitting” subject with the “standing” subject.
• While your partner is seated with their hand resting on the lab table,
record their pulse while they perform the Valsalva maneuver.