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					                                 Homeostasis Lab
          The Effects of Exercise on Homeostasis
A: Purpose: To discover the effect that various levels of exercise have on specific body

B: Hypothesis: How do you predict the 6 observed and measured parameters will change as
the subject exercises?

C: Materials

Thermometer, Blood Pressure/Heart Rate Kit, Stop watch (or the second hand on the clock a the
front of the room), Ethanol, Cotton Balls

D: Introduction

Exercise causes many homeostatic factors to kick in, in an effort to maintain internal homeostasis.
How exercise affects some of these homeostatic factors can be determined by measuring and
observing certain parameters such as:

          o   Change in skin color on arms and face
          o   Perspiration Level
          o   External Body Temperature
          o   Heart Rate
          o   Blood Pressure
          o   Breathing Rate

In the following lab 1 member of your group of 4 will exercise for 8 minutes by doing jumping jacks.
The parameters listed above will be recorded at rest, 2 minutes, 4 minutes, 6 minutes, 8 minutes,
and 1 minute after exercise has stopped. The subject should stop just long enough for the needed

Each group will record their results in the table provided. Your final lab report should follow the
laboratory report outline provided. As well, your report is to include a graph for each of the 4
measured parameters (i.e. body temperature, heart rate, blood pressure, and breathing rate). The
questions at the end of the lab should be part of your result and discussion sections.

E: Procedure

   1. Each group should obtain: a thermometer, blood pressure/heart rate kit, and a stop-watch.

   2. Before proceeding with the lab each group should be sure that they are able to obtain
      readings using the blood pressure kit. The cuff should be attached directly to your skin just
      above the elbow joint. The black tube exiting the cuff needs to be resting on the inside of
      your arm at your elbow where a pulse can be measured. In order to avoid an "error" reading
      the subject needs to be perfectly still when you are taking blood pressure/heart rate
      measurements. Begin by inflating the cuff, using the black bulb, the monitor will beep when
     the cuff is sufficiently inflated. The monitor will take the blood pressure reading and heart rate
     as it slowly releases air from the cuff. At the end both a blood pressure and heart rate
     reading should appear on the monitor screen.
  3. Record the resting observations and values of your subject for each of the 6 parameters.

        i.   Record normal skin color of hands and face
       ii.   Record normal perspiration level (i.e. none, mild, medium, high)
      iii.   Record external body temperature by placing the thermometer under the subjects arm
             pit for 1 minute. Note: measurements should be taken directly from the skin! (roll up
             your sleeve before you begin)
      iv.    Record the resting blood pressure and heart rate using the blood pressure cuff/heart
             rate monitor.
       v.    Determine the breathing rate by counting the number of breaths taken in 1 minute.

  2. Have your subject begin jumping jacks. Please note your subject should be sure to exercise
     at a level that they can maintain for the entire 8 minutes.
  3. Take your subjects parameter readings, using the same techniques described above at the
     2, 4, 6, and 8 minute time markers. Be sure to take final readings 1 minute after your subject
     has stopped exercising.
  4. Record all of your parameter readings in the table provided.
  5. After cleaning your thermometer with ethanol, return it along with your other lab materials to
     the back of the room.

F: Analysis Questions

  1. Plot your measured data on 4 graphs (use graph paper, rulers, label, title). You should plot 1
     graph each for body temperature, heart rate, blood pressure and breathing rate versus the
     duration of exercise (i.e. rest, 2,4,6,8, 9 minutes). PLEASE NOTE: When plotting your blood
     pressure graph you should show one line for systolic pressure (the higher number) and
     another line for diastolic pressure (the lower number).
  2. Describe your results for each of the 6 parameters. (This means to actually put in words what
     the graph is depicting)

G: Discussion Questions

  1. What are the changes you observed in body color and perspiration level in response to?
     Explain how do these changes contribute to the maintenance of homeostasis?
  2. Was there a change in body temperature? If so describe this change. Did you find this
     change surprising? Why or why not? What mechanisms does your body use to maintain its
     homeostatic temperature?
  3. Explain to the best of your knowledge, why does and increase in heart rate and breathing
     rate accompany exercise?
  4. Explain the results you obtained for diastolic (lower number) and systolic (higher number)
     blood pressure. Note the previous question.
  5. By studying your parameter measurements after exercise has stopped, what conclusions can
     you draw about your body’s ability to maintain homeostasis?
  6. Why is this lab an example of homeostasis?
H: Observations

           Body Color   Perspiration      Body       Heart Rate     Blood     Breathing
                           Level       Temperature                 Pressure     Rate
                                        (Celcius)                  (mmHg)     (breaths/







1 minute

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