Daphnia Heart Rate Lab Report

Effect of Chemicals on Daphnia Heart Rate
Background:
In the world today, there are many chemicals that people use to fix or help with issues within their own bodies. Some of these chemicals may include things like caffeine, nicotine, and alcohol. These supplements can have substantial effects on other things within the body like the brain, liver, and especially the heart. For example, many chemicals like caffeine, nicotine, aspirin, and sleep aid all have effects on the body which can cause your heart rate to increase outside of normal range. Other supplements like alcohol have showed a decreased heart rate due to reactions taking place in the body. While many people are constantly filling their bodies with these chemicals to fix problems
In my research, I found that many over the counter sleep aids have a side effect which can make your heart race, but upon thinking about the purpose of sleep aid more, it is more likely that sleep aid will slow down your heart rate allowing you to relax your body and fall asleep. This also corresponds with the melatonin that is released in your body before sleep after a sleep aid is taken because melatonin is seen to reduce your blood pressure, allowing you to relax. Therefore, the sleep aid would most likely follow the pattern from the lab by decreasing heart rate. However, there also may be some sources of errors during this lab. For example, only one person in my group was in charge of counting the heart rate and one doing the time, but the heart rate was extremely fast on the Daphnia. This made it hard to count and led to some mistakes in the ten second interval times. Also, the Daphnia used in this lab were not all the same size which may have effects on the heart rate. The larger Daphnia may not be affected as much by the chemicals due to the larger body mass which may lead to discrepancies in the data. However, despite some errors, there is sufficient data from multiple groups to say that nicotine, caffeine, and aspirin increase heart rate, while alcohol and sleep aid decrease heart rate. If I were to do this lab again, allow the chemicals to set in for longer amounts of time to make sure the chemical has taken full effect. Also, I would use a machine to count the heart beats on the Daphnia to ensure a more accurate count. It would also be interesting to see if the heart rates in humans are similar in percent differences based on the percent differences from the Daphnia. Through research before the lab, and obtaining an abundance of data from other class groups, caffeine, nicotine, and aspirin will consistently increase heart rate in Daphnia and carry