In this project, we explored the different ways your body maintains it's internal balance, also known as homeostasis. My group and I had to choose a way homeostasis is maintained, then conduct an experiment to prove it. Afterwards, we did the experiment and showed our results in a scientific poster. My group decided upon thermoregulation, the process that maintains your body's temperature.
Thermoregulation keeps internal body temperature stable. In humans, the average temperature is 98.6 degrees F. This temperature can be influenced by a number of factors; drug use, alcohol consumption, metabolic conditions, and weather cool the body, while fever, digestion, exercise, and weather warm the body. No matter the conditions, thermoregulation should always bring the internal body temperature back to 98.6 degrees F. The hypothalamus of the brain is the body’s thermostat. When nerves in the skin or blood detect abnormal temperatures, they send signals to the hypothalamus. The brain sends a message to the thyroid gland, which secretes hormones that trigger a cooling or heating process. Cooling happens through sweating, vasoconstriction, and panting. Warming happens through goosebumps, vasodilation, and shivering.
Experiment
The first step in our experiemnt was to have the test subject take their temperature. We then had them describe how warm/cold they felt (they should currently be wearing a short-sleeved tee shirt and jeans). Next they put on a sweatshirt and it’s hood, a down jacket (or ski jacket), a scarf, and a warm hat. They then had to stand still for 15 minutes, record their temperature every minute, and describe how they felt (sweating, flushed, etc.) Take off the excess clothing once the 15 minutes are over. Start a stopwatch and take their temperature every minute (record it). Set a timer for 5 minues and take their temperautre every minute. Their body should return to it’s original temperature (it should be around 98.6˚F). Keeping only their pants and shirt on, go outside and record their temperature every minute for 15 minutes straight. Have them describe how they feel. Go back inside once the 15 minutes are over and set a timer for 5 minutes, recording their temperature every minute. Record the data.
Abstract
Thermoregulation aids the maintenance of homeostasis in the body by keeping internal body temperature close to 98.6℉. The hypothalamus detects the irregular body temperature and sends messages throughout the body to take action. To test this phenomena, we wrapped 4 subjects in warm layers for 15 minutes, waited 5 minutes for their body temperature to return to normal, and took them outside in only a short sleeve shirt, jeans, and shoes in 60℉ weather for 15 minutes. In both warm and cold conditions, they had symptoms of homeostasis. While wrapped in layers, they had fairly thick veins and traces of sweat. Their bodies reacted to the cold environment through shivers, thin veins, and goosebumps. All of our participants’ temperatures stayed within 2-3 ℉ throughout our entire experiment. This proves that thermoregulation effectively regulates body temperature and maintains homeostasis.
Introduction
The human body is a complicated, delicate system. To function properly, an internal balance needs to be maintained. This is done through the process of homeostasis. Homeostasis regulates a number of levels in the body through positive and negative feedback. Positive feedback speeds up the direction of change, like lactation in mothers. Negative feedback reverses the direction of change, like the regulation of blood pressure, blood sugar, and water. This study is designed to focus on thermoregulation. Thermoregulation keeps internal body temperature stable. In humans, the average temperature is 98.6 degrees F. This temperature can be influenced by a number of factors; drug use, alcohol consumption, metabolic conditions, and weather cool the body, while fever, digestion, exercise, and weather warm the body. No matter the conditions, thermoregulation should always bring the internal body temperature back to 98.6 degrees F. The hypothalamus of the brain is the body’s thermostat. When nerves in the skin or blood detect abnormal temperatures, they send signals to the hypothalamus. The brain sends a message to the thyroid gland, which secretes hormones that trigger a cooling or heating process. Cooling happens through sweating, vasoconstriction, and panting. Warming happens through goosebumps, vasodilation, and shivering. The experiment above will show how the internal temperature relates to how the subject feels externally. When the subject puts on layers, they will feel warm. When they stand outside in the cold morning air, they will feel cold. Will their internal body temperature change? Or will homeostasis ensure that it stays at 98.6 degrees F? From our research, our hypothesis is that their internal body temperature will remain the same.
Hypothesis
We predict that our subject's temperatures will stay relatively the same inside and outside due to thermoregulation.
Materials and Methods
Our test subjects were four 14-15 year-old girls wearing jeans and short sleeve shirts. We tested them two at a time in order to use the same temporal thermometer every time. First, we took their baseline temperature. Then, they layered warm clothes in this order: sweatshirt with the hood on, warm jacket, thick knitted neck wrap, and warm hat. We recorded their internal body temperature and description of how they felt every minute for 15 minutes. We periodically asked to see their veins and whether they were sweating and looked to see if they were flushed. Afterwards, they took off the layers, and we recorded their body temperature every minute for 5 minutes. Following this we took the subjects outside, where it was around 60 degrees F, to record their body temperature and description of how they felt for 15 minutes. We periodically asked to see their veins and asked them to tell us when they felt goosebumps or shivers. Next, we went back inside and measured their temperature every minute for 5 minutes in the normal classroom conditions. To finish, we repeated this process for the other two subjects.
Results
Participant 1’s baseline body temperature was 98.5℉. With the layers on, her body temperature increased about 0.1℉ per minute. From four to six minutes her body temperature remained at 99℉, and at nine minutes it reached a high of 99.4℉. While wearing the layers, she said she felt toasty and flushed. After five minutes without the layers on, Participant 1 returned to her original body temperature, 98.5℉. Next she went outside where the temperature was about 60℉. Her temperature immediately dropped down to 96.4℉ after three minutes, but then rose slightly and fluctuated between 96.5℉ to 96.7℉. Her lowest temperature was 96.4℉, which she reached briefly at three minutes and finally at fifteen minutes. Participant 1 had mini, sporadic shivers and prominent goosebumps while she was outside. Her toes, hands, and nose were all numb. Her veins were thinner and less visible. After five minutes, Participant 1’s body temperature was at 98.2℉. Participant 2's baseline temperature was 98℉. With the clothing layered on her, her body temperature stayed between 98℉ and 98.7℉ with the exception of 97.9℉ at one minute. After 15 minutes in the clothes, her body temperature was at 98.3℉ and she felt pleasantly warm. She removed the clothes and sat for five minutes. She said she felt uncomfortably cool -- despite her increasing temperature-- until the fifth minute, where she felt good. Her temperature ended at 98.3℉ once again. We went outside and her temperature dropped to 97.6℉ after the first minute. Her temperature continued to decrease, until seven minutes where her temperature was 96.3℉. She said she had goosebumps and was “freezing” after the seven minutes. Her temperature increased to 96.7℉ at ten minutes. It then fluctuated and finally ended at 97.3℉, and she said she still felt chilly, but not as cold as she had been before. She went back inside and her temperature increased and then decreased to 97.7℉. She said she felt relatively comfortable but still a little bit chilly. Participant 3’s baseline body temperature was 98.7℉. She said that she felt normal except for slightly cold hands. Her temperature fluctuated. She was already at 99.3℉ by the first minute. It continued to decrease until 5 minutes, when her body temperature was 98.6℉. She described feeling warm in the core and head, but she had cool hands and thin wrist veins. From there, her temperature increased at a fairly constant rate of 0.1℉ per minute. She noted that her right hand, which she took out of her pocket periodically, felt cooler than her left. Her left palm was slightly moist from sweat, and her veins were thicker and more prominent. Her temperature was 99.4℉ at the end of the 15 minutes. Without the layers, her temperature decreased to 99, then increased to 99.4℉. When she went outside, her temperature dropped to 98.4℉ within the first minute. In the 15 minutes, her temperature stayed between 98.4℉ and 98.8℉, ending at 98.8℉. She described little shivers that increased in intensity as time progressed. Her arms and hands were cold, but her core was still warm. Her wrist veins were barely noticeable at 12 minutes. She had less goosebumps, but the shivers were bigger. After 5 minutes in the classroom, Participant 3 warmed to 98.9℉. Participant 4's baseline body temperature was 97.3℉. When she put the layers of clothing on, her body’s temperature increased by about 0.1℉ each minute. At 8 minutes in the heat, her temperature started to fluctuate until ending at 99.5℉ after 15 minutes. Participant 4 said that she felt increasingly warm up until 8 minutes, after which she felt cooler. After 5 minutes without the layers, Participant 4’s body temperature was at 98.7℉. When she went outside, her temperature fluctuated but stayed around 97.8℉ throughout the 15 minutes. At 8 minutes, with a temperature of 97.5℉, Participant 4 said she had goosebumps and was starting to have mini shivers. After 15 minutes outside, she was at 97.8℉. After returning inside to the classroom, her temperature increased each minute, until ending at 98.3℉ after 5 minutes. She said that at 98.3℉ she felt like she was at a pleasant temperature, but her hands were still a little cold.
Discussion and Conclusion
For this project we ran into many things we could have done differently, and other things that went really well. First, as we tested for warmth we ran into some difficulty with the room temperature greatly fluctuating. We started by setting the heater to 70℉, but it would go up to about 74℉ then the a/c would go and make it 67℉. This made it much more difficult to track because we would have our huge jackets on and all the sudden get cold. On the other hand, even with lots of change in temperature all four subject's body temperatures stayed between 100℉ and 96℉. This is a good data set for showing how our body maintains its temperature. The data from this experiment shows how homeostasis is helped maintained through thermoregulation. It is shown because when the test subject was wearing multiple layers, their veins appear bigger and more prominent. This shows the body's way of trying to cool the person off. When the veins widen, blood from the warm core is able to be dispersed throughout the body. The opposite applies to when the body is cold. For example, when the test subjects went outside, their veins were thinner and less prominent. Their body was trying to keep their core warm. Other signs of thermoregulation are sweating when hot and shivering when cold. All the participants in the experiment experienced these symptons while being tested. Thermoregulation was also shown because even though the participant's body temperatures fluctuated, they stayed relatively close to their baseline temperature. This shows how the body is working to keep it's temperature in balance. After the test subjects were brought back to normal temperatures and conditions, their body temperature quickly returned to it's baseline.
Concept
Homeostasis: your body's ability to keep everything stable
Reflection
This was a fun project. I enjoyed the freedom of getting to design your own experiment. My group and I worked wonderfully together. We were great at communicating. We each shared our input and ideas and analyzed things together. We also all stayed on task and put in the same amount of work. One problem my team came across was that we did not manage our time well. We spent too much time on some things that caused us to be rushed near the end of the project. Another problem was that the temperature in the room kept changing instead of staying constant. This caused our data to be less accurate. One thing I need to work on are my presenting skills. I still need to be more confident in what I am saying and less timid.