Reflex Lab Analysis

For this lab we got to test and observe some of the reflexes our bodies have developed to protect ourselves. Involuntary reflexes happen when the information received doesn't pass through the brain, it hits the spinal cord, is very quickly processed and it sent strait back to the muscle that it needs to activate. We first tested one of my favorite reflexes, the photo-pupillary reflex, because it was one I messed around with and watched my pupil grow and shrink in a mirror. To test this and show exactly how it worked, I covered one eye for about a minute to really get it to adjust to no light, then I uncovered it and stared right into the flashlight of Amelia's phone while she recorded the pupil shrinking at the light. Now I am going to go further into detail about each of these reflexes. The first one of the photo-pupillary reflex happens because the eye needs to adjust to the amount of light provided so that it can see clearly and function in different amounts of light. Amelia took a short video of my pupil shrinking but you couldn't see it very well as my hair came down and obscured it.

This is the pupil when there is lots of light entering it. 

Next we did the experiment every kid knows about, the "hitting your knee with an hammer and kicking someone" or more scientifically, the patellar reflex. For this we took a rubber hammer as to not injure our knees, and tested the reflex and observed how vigorous the reflex was and then re-tested it after doing 30 squats. After the squats the reaction wasn't reduced too much but it definitely wasn't as fast or violent because all thing in the body require ATP, so when the ATP had been used up by the squats (contracting the muscles that would cause the patellar reflex) the reflex would not occur.

After testing that we went back to the eyes and tested our blinking reflex by throwing a cotton ball at our friends eyes, which were protected by cling film to see how we blink even with protection in front of us. Our corneas are very delicate and because they have no blood supply, they cannot heal themselves so it would be very bad if we hurt our corneas. That is why we instinctively blink, so that we protect our eyes from being damaged.

Next we tested a reflex not too many people know about which is used to test for brain damage, but if present is called Babinski's sign, where when a pen is drawn up the bottom of our foot, it will either curl up or spread out depending on our brain. If the person extends their toes, unless they are an infant, it is a sign of serious brain damage, but if they curl their toes, which I did in our experiment, they are healthy.

The final test was probably the most relevant to our lives today as teenagers who are glued to phones. We tested our reaction times, something that does require thought bc it is something that we need to think to do. We had our partner drop a ruler and we had to catch it as quickly as we could, and suing that measurement, estimate our reaction time. The first table below s the data from that control test and the one below shows the results of the same test, but we were texting while trying to catch it. As you can see, our reaction time was slowed significantly by the "multi-tasking" which does not technically exist as the brain can only do one thing at a time. Everyone in our class had a slower reaction time while their minds were preoccupied as you can see in our data tables as well as the graph that pooled together all of our classes data on response time as well as the difference between girls and boys.

Control Reaction Times

Reaction Times While Texting