Homeostasis Lab Activity

Questions to be investigated

  • How does the body respond to exercise?
  • What factors of homeostasis might be affected by exercise?
  • What measurable clues are there that the body is changing to maintain homeostasis?

Materials

For each pair of students:

  • Blood pressure cuffs (Sphygmomanometers and stethescope)
  • Thermometer and cover (to measure body temperature; can be traditional or skin adhesive)
  • Cotton swabs and alcohol (for cleaning earpieces)
  • Stopwatches (or cell phonetimer)

Procedure/Description of Lesson

  1. You and your table partner will work together, one student will be the recorder and one student will be the exerciser. The exerciser should be seated and quiet for 1 minute. Record the initial state of the body. Record in table.
  2. At the signal, the exerciser should begin running in place, doing jumping jacks or other aerobic activity. Whatever you choose to do you should do for exactly 2 minutes. The timekeeper/recorder will tell the exerciser when to stop.
  3. At the end of the 2 minutes, immediately make observations and measurements of the exerciser. Record data in the data table.
  4. As soon as possible, the exerciser should begin another 2 minutes of exercise.
  5. This process will continue until the exerciser has completed 8 minutes of exercise in 2 minute chunks (with data recorded every two minutes) and all data is recorded.
  6. When the 8 minutes is up, the student exercising will rest for 2 minutes. After 2 minutes, observations and measurements will be taken for the final time. This data will be recorded on the data table.
  7. Thermometers and other supplies should be cleaned before returning to the common supply area. Clean the stethescopes with alcohol and return it and all other lab materials to the designated area.

Heart Rate
(Beats/min) / Breathing Rate
(breaths/
min) / Body Temperature
(°F) / Perspiration Level
(Sweating or not, mild, medium, high) *qualitative / Blood Pressure
Systolic/Diastolic
(mmHg) / Skin Pigmentation
(Normal, Patchy, Flushed) *qualitative
RESTING/ Basal Parameters
After 2 Minutes of Exercise
After 4 Minutes of Exercise
After6 Minutes of Exercise
After 8 Minutes of Exercise
After 2 minutes of rest

Graphing

You and your partner should each graph two of the following graphs so there is no overlap among you but so that there is a graph for each of the conditions.

  1. External Body Temperature vs. Various Intervals of Exercise
  2. Breathing Rate vs. Various Intervals of Exercise
  3. Heart Rate vs. Various Intervals of Exercise
  4. Blood Pressure vs. Various Intervals of Exercise (optional) 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).

Alternately, each student in the group can be assigned a different one of the graphs for their group. Results and graphs can be used to answer questions below and stimulate discussion.

Discussion/Post-Lab Questions

  1. What aspects of the “normal” body conditions were changed by this activity? What were the issues that made a homeostatic response necessary?
  2. What responses did the body use to maintain homeostasis?
  3. What body systems were involved in the criteria we measured today, and how?
  4. Why does an increased breathing rate accompany exercise?
  5. Why does an increased heart rate accompany exercise?
  6. Explain how this experiment demonstrated homeostasis and negative feedback.
  7. What are some ways that your body regulates the increase in body temperature that occurs by exercising?