Introduction for Part 1
The regulation of internal body temperature is important to the survival of organisms. Every animal does this differently, but the common goal at the end of it all is to have the internal temperature required to catalyze reactions and biochemical processes inside the body. There are two main types of internal temperature regulation strategies performed by animals, ectothermy and endothermy. Ectothermic animals keep their internal temperature stable using the external environment, and Endothermic animals use the heat produced from their metabolism to keep their internal temperatures stable. Along with these two main strategies, animals also use a mix of other physiological, anatomical, and behavioral adaptations to help make these processes as efficient as possible. These include surface area to volume ratios, the use of fat or fur to assist in insulation, hibernation, and basking practices. For example, in order to avoid lethal internal body temperatures endotherms need to be able to dissipate that heat quickly (Nilsson et al. 2016). One strategy that can be used for this problem is by having a high surface area to volume ratio. In our case as humans, we use this method along with our superior ability to cool off through perspiration. The goal of the experiment in part 1 will be to observe the effects of external temperature on the heating and cooling of an organisms internals.
Experimental Method for Part 1
In our first experiment, we took kitchen-grade aluminum foil and made a roughly ten-cubic-centimeter cube shape out of it to represent the body of an animal, most likely an ectotherm in this case. We then took the initial temperature of the inside of the cube, using a basic glass thermometer, prior to its heating. Once we recorded this initial temperature, we placed the aluminum cube about fifteen centimeters under a heat lamp to replicate sun exposure. While under the heat lamp, we took temperature readings of the inside of the cube every thirty seconds. We continued to record until a temperature plateau was reached, turned off the heat lamp, then recorded the temperature until it roughly reached the initial temperature prior to placing the cube under the heat lamp.
Results for Part 1
The initial internal temperature reading of the aluminum cube was 25°C. It took approximately 18 minutes total for the cubes interior to reach maximum temperature and return to baseline. For the first nine minutes, the interior heated at rate of roughly 0.5°C per 2-3 minutes. Peak temperature of 26.9°C was reached and sustained from 9 minutes to 11:30 minutes. At the 11 minutes mark, we turned the light off and recorded the cooling period. The rate of cooling was roughly 1°C per 2-3 minutes until it reached baseline around the 18 minute mark.
Conclusion of Part 1
We observed that the heat emitted by the heat lamp was able to slowly heat the interior of the aluminum foil cube to a constant temperature of 26.9°C. This aluminum cube in the experiment is most analogous with ectotherms, as it lacked a large size, insulation, or an internal source of heat. Variables that may have affected the accuracy of the data collected include sunlight exposure from nearby windows, the aluminum material having a specific heat capacity that influenced how the heat was absorbed, other openings in the cube allowing heat exchange with the external environment, and the position of the cube to the heat lamp used in the experiment.
References
-Nilsson, J., Molokwu, M. N., & Olsson, O. (2016). Body temperature regulation in hot environments. PLoS One, 11(8) doi:http://dx.doi.org.proxy.lib.utc.edu/10.1371/journal.pone.0161481
