STEM Homeostasis Water Level Lab

Evidence Of Work

In this project, we tested the hypothesis that the amount of water consumed by a person will impact how quickly they need to urinate to maintain homeostasis. Homeostasis is the tendency for the body to change to bring itself back to equilibrium. The belief was that a person who drank a large volume of water would need to urinate more quickly than a person who drank a smaller amount of water.

To test this hypothesis, we used a group of 4 individuals. Each was assigned to drink a certain amount of water at a starting time, and then measured the time to urination by using a timer. One person drank no water, while the other persons drank 1, 2, or 3 cups of water. The results supported the hypothesis because the person who drank 3 cups of water had to urinate in the shortest amount of time. The other group members had a similar pattern of needing to urinate more quickly based on how much water they drank. The pattern was linear when the amount of water drank was plotted against the time to urination. Larger amounts had shorter times to urination, and no water drank had a long time to urination.

Content

Homeostasis: The tendency for the body to change and bring itself back to equilibrium. Homeostasis in our case was the body maintaining its water level through sweat and urine.

Positive Feedback Loop: Occurs in nature when the product of a reaction leads to an increase in that reaction. If we look at a system in homeostasis, a positive feedback loop moves a system further away from the target of equilibrium.

Negative Feedback Loop: A reaction that causes a decrease in function. It occurs in response to some kind of stimulus. Often, it causes the output of a system to be lessened; so, the feedback tends to stabilize the system. This can be referred to as homeostasis, as in biology, or equilibrium, as in mechanics.

Stimulus: A thing or event that evokes a specific functional reaction in an organ or tissue or a thing that rouses activity or energy in someone or something; a spur or incentive.

Signal: A gesture, action, or sound that is used to convey information or instructions or a transmit information or instructions by means of a gesture.

Response: Any behavior of a living organism that results from an external or internal stimulus.

Reflection

This project worked well and allowed us to test the hypothesis about how biologic systems handle intake of water to maintain homeostasis by getting rid of water through urination. Two things we did well were 1) finding a way to coordinate how to measure time to urination when we all had different schedules and 2) bringing the group together to report our results. Things we could have done better or different would be to 1) see how body mass index affects the time to urination and 2) to see how different types of liquids affect time to urination by running the experiment with a different liquid like soda.

A few of the "C"s that were demonstrated during the project were communication and collaboration. Communication was required to make sure that we were all organized and knew who was assigned to which task and amount of water. Collaboration was shown by all team members working together and balancing the workload to get the project done on time and ready to present in front of the class.