This experiment is designed to answer this investigative question:
How does the body maintain homeostasis by regulating its internal temperature, and how does it respond to changes in temperature?
You will need a Data Table. You can Download the template spreadsheet (Neocities wouldn't let me upload it, so this goes to Box - the page should have a Download button in the upper-right corner) or create your own containing the following fields:
- Ambient temperature from room temp., warm, and cold environments
- Body temperature at rest from room temp., warm, and cold environments
- Body temperature immediately after activity in warm and cold environments
- Body temperature after cooldown (rest after activity) in warm and cold environments
- Change in body temperature from before exercise to after
- For body temperature at rest, take the differences between warm and cold, warm and room, and room and cold.
- How long you rested after each span of activity
You should also have some place to record your qualitative observations.
Before starting the experiment, you will want to create a hypothesis. You should try to create one yourself, but here is a sample:
If the body's internal temperature is changed from its setpoint, then the negative feedback loop in the body designed to regulate temperature will return it to its setpoint by either sweating or shivering, because the change will be detected by thermoreceptors and signaled to the hypothalamus, which will trigger the appropriate response, either sweating for high temperatures or shivering for low temperatures.
Procedure:
- Step 0: A good exercise for you before starting the lab would be to determine the independent, dependent, and controlled variables. There is space on the data table template for you to write these in. If you choose not to, they will be explained in the Data Analysis section.
- Step 1: Find somewhere to perform the experiment. To complete the data table, you will need one cold environment, one hot environment, and one environment at room temperature. If you cannot find one of the extremes, try to find two environments which have quite different temperatures, even if they are both somewhat extreme. If you cannot find all of these environments, you can still gather some useful data regarding heat generated internally by muscle activity.
- Step 2: Gather materials:
- Thermometer / temperature sensor to measure the temperature of the environment
- Thermometer to measure internal body temperature
- Step 3: Record your body temperature at rest in a room-temperature environment and record it into the data table. This gives us a baseline measurement to see how the temperatures of the other environments affect internal body temperature, even while at rest.
- Step 4: Move to a cold environment. Use a temperature sensor to measure the temperature of this environment and record this into the data table. Make sure you give the temperature sensor adequate time to fully update its measurement.
- Step 5: Spend time at rest in this environment until the temperature does not feel particularly cold anymore. This should allow time for any change in your body temperature to take place. Then, record your body temperature into the data table. (You have now collected the data for the stimulus of a cold environment.)
- Step 6: Do something that requires quite a bit of energy for three minutes. This could include running, lifting heavy things, doing jumping jacks, or a similar exercise. Do what you have room for in the environment to increase your muscle activity as much as you can. Once complete, immediately record your body temperature into the data table.
- Step 7: Rest until any soreness, heat, or other byproduct of the exercise disappears and you have returned to a normal state. Then, record your body temperature into the data table. (You have now collected some of the data for the stimulus of heat generated internally by muscle activity.)
- Step 8: Repeat steps 4-7 in a warm environment.
- Step 9: Complete the data table, performing the necessary calculations to fill in all fields. (If your data table is the spreadsheet template, some of these fields should populate automatically.)
Now that you have completed the lab, you may want to compare your data against my data.