CSB #8: Blood Pressure and Pulse Rate Experiment by Madhu and Angie

Authors: Angeline Pan and Madhu Nori

While exercising, the heart needs to pump blood faster and in larger amounts to all of your body because you are using up your oxygenated blood quickly. After exercising, have you ever felt a fast throbbing sensation throughout your body and a higher pulse? This is because your heart has been doing its job. However, when sleeping or resting, your body does not have to work as hard to get blood to the rest of your body.

In this experiment, Madhu and Angeline tested what would happen to our blood pressure and pulse if our physical position/state was altered. We tried 3 different positions and one state of exercise: lying down, sitting on a chair, standing, and after doing 40 jumping jacks.We wanted to see how blood pressure changes with each position/state and determine why this happens. We hypothesized that if a person were to lie down, sit, stand, and do 40 jumping jacks, then the blood pressure would be lowest while lying down and gradually increase to the highest blood pressure after exercising.

During this experiment, we used the logger pro application on our laptop to connect the blood pressure sensor to collect the data. First, the test subject, Angeline, lay down for five minutes and while Madhu wrapped the blood pressure sensor around her arm and recorded the blood pressure and pulse. We then proceeded to repeat this process three more times, but for sitting down, standing, and right after exercising.

Awkwardly lying down on the ground

Sitting

Standing up!

Working hard, AKA doing jumping jacks ;D

We found that our hypothesis was correct: run 1 (lying down) resulted in 109/63 & a pulse of 67, run 2 (sitting) resulted in 112/71 & a pulse of 70, run 3 (standing) resulted in 124/78 & a pulse of 83, and lastly, run 4 (after 40 jumping jacks) resulted in 136/85 & a pulse of 108. There is not that large of a difference in the blood pressure, however there is a slightly larger difference between the pulse rates.

Overall, our experimental hypothesis was supported by our data. We think this ordering is correct because lying down requires the least energy, sitting requires a little more, standing requires even more, and doing jumping jacks is the most tiring. Because the muscles of the body must function more as the body requires more energy, blood must flow faster. Thus, due to the lack of adequate amount of blood, the heart is signaled to pump more and support the muscles. Furthermore, as the heart pulse rate increased, pressure would increase likewise because more liquid is forced through the vessels at a higher speed.