Bio102

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• Bio102
• Laboratory 6
• Blood PressureECG (EKG)

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Objectives for Todays Lab

• Blood Pressure
• Become familiar with determining pulse rate
• Become familiar with taking a blood pressure
  reading and with using a sphygmomanometer (lt- can
  you spell this? ?)
• Correlate the effects of various experimental
  conditions on pulse and blood pressure
• ECG
• Acquire a better understanding of the theory
  behind the ECG
• Record and analyze an ECG
• Computers set up in lab
• You will conduct a one-lead ECG on a lab partner
• Identify the components (waves, intevals) of a
  normal ECG
• Describe the phases of the cardiac cycle
  represented by each wave form on the ECG
• Calculate heart rate from an ECG
• Identify the beginning and end of the PR, QRS,
  and QT intervals

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Location of Pressure Points
Temporal artery
Facial artery
External Carotid artery
Brachial artery
Radial artery
Femoral artery
Pulse beats/30 sec X 2
Popliteal artery
Posterior tibial artery
Dorsalis pedis artery
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Pulse in Lab Today

• Use the radial artery of your partner, and use
  your index finger
• Note the characteristics of the pulse
• Regular, irregular
• Strong, weak
• Count number of pulses in 30 sec. and multiply by
  2 to get the pulse rate
• Do this sitting down, standing up, and after
  exercise

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Heart Sounds

• Lubb (S1)
• first heart sound
• occurs during ventricular contraction
• A-V valves closing

• Dupp (S2)
• second heart sound
• occurs during ventricular relaxation
• semilunar valves closing

?
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Heart Sounds
Listening to the heart (auscultation) is done
using a stethoscope (can you spell this?) Because
sounds must pass through several layers of
tissue, sounds are not heard directly above their
point of origin S1 Lubb (1 looks like L) S2
Dupp (2 curved like D)
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Heart Sounds
Auscultate over the left sternal border about the
level of the 3rd or 4th rib Find the point where
you can hear the sounds the best, and use that
Remember lubb-dupp ltpausegt lubb-dupp ltpausegt
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Auscultatory Method of Determining Blood Pressure
Use an average bp from two different readings
from both arms. Do this standing up, sitting
down, and after exercise Korotkoff sounds
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For the BP portion of todays today

• If you need a bit of background and havent read
  it already, take a look at the first few pages of
  todays handout
• Also see Mariebs Lab Manual, pp. 501-508

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Great Book on Cardiovascular Physiology
Excellent reference for cardiovascular
physiology Author R. E. Klabunde
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A GREAT Book on ECGs
This is you after reading the bookconfident and
no longer intimidated by ECGs!!
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Electrocardiogram
Millivolts
Time
PR Interval 0.12 0.20 sec QT Interval 0.20
0.40 sec QRS Interval lt 0.10 sec
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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The Bipolar Limb Leads
We will be using only Lead II today, so the right
arm will be negative, and the foot will be
considered positive
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The Electrocardiogram
A wave of the ECG will be positive (up) when the
positive wave is moving toward the positive
electrode
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Electrocardiogram and Heart Events
Right Arm(-)
Left Foot ()
Recall that the left foot electrode is POSITIVE,
so when the wave of depolarization is moving
toward the left foot, we get a positive (up)
deflection on the ECG
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Electrocardiogram and Heart Events
Right Arm (-)
Remember that the T-wave represents
repolarization of the ventricles.
Left Foot()
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ECG Animation
NYU ECG tutorial site
This is available on Links to Explore for Lab 6
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The Paper Chart ECG
Small boxes are usually 1 mm on each side
Ten mm high represents 1 mV
0.04 sec
0.2 sec
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The Paper ECG Chart
How long is the PR interval on this strip? The
QT interval? (See Mariebs Lab Manual pg. 461-462
for further explanation of these)
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Calculating the Heart Rate
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Calculation of Heart Rate
As shown in the sample ECG below, you will
calculate your heart rate by measuring the time
between 5-8 beats of your heart (4 beats shown
below). Then, to determine your heart rate from
that, use the following proportion Beats
measured (beats) 60 seconds / Total time
measured (sec) Heart rate (bpm)
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For the ECG portion of todays lab

• If you havent read it already and need a bit of
  background, see Mariebs Laboratory Manual pp.
  461-464
• Run the ECGs for each member of your group by
  following the Procedure in your handout
• Follow the instructions for the PowerLab ECG
  module in your handout
• Be sure electrode placement is correct
• Input the correct bioamp settings to reduce
  interference
• Be sure to record values you measure on the EGG
  on the computer while you have them on the
  screen, and then transfer them to the ECG strip
  after you print it
• Print each persons ECG and directly on the
  printed ECG
• Show calculations for the heart rate
• Mark the PR, QRS, and QT intervals on hard copy
  with their times (that you recorded when they
  were on the screen)
• Indicate the P, QRS, and T waves and what they
  mean

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What you should do in lab today

• After EACH member of your group has an ECG
  recorded, be sure to SAVE the ECG into a file
  until the lab is over (just in case)
• Select File Save As (to prevent overwriting
  someone elses file with your data)
• Enter a file name using your first and last name
  with no spaces as the file name, e.g., SueCidal).
  
• File is saved to the Desktop, so when you
  retrieve it later to analyze the data , LOOK ON
  THE DESKTOP!

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Next Lab

• Lab 7 - Microcirculation
• We will be examining the circulation in
  arterioles, capillaries, and venules
• In a goldfish tail (a real one not the cracker)
• Examining the effect of various
  substances/factors on circulation
• See the handout online