Reflexes Lab

5/6/15

Reflexes Lab

1. Photopupillary Reflex
1. Recap: Have partner shield one eye from the light for a few minutes. Position a flashlight close to that eye. Have partner remove hand quickly. Watch for change in pupil size.
2. Claim: Pupils adjust in size based on the amount of light. 
3. Evidence: In our group, my partner's pupil got a lot smaller (in comparison to her other eye) after she removed her hand.  You can see the video below of how one's pupil changes based on the amount of light (video courtesy of Jennifer Poo).
4. Reasoning: Pupils constrict or dilate depending on the amount of light because it allows more/ less light into your eye in order to help you see in bright/ dark situations. This also might help in a fight/ flight situation as your eyes focus on the danger.
2. Knee Jerk Reflex
1. Recap: Tap partner's knee with hammer. Observe how fast and how great the reaction is. Then have partner do 30+ air squats and retest. Observe how the reflex changed.
2. Claim: Knee reflex happens faster before squats.
3. Evidence: The reflex before the air squats was a lot greater as my leg kicked higher than after I had performed the squats. Also my leg moved a lot slower after the squats and barely moved in comparison to before.
4. Reasoning: The squats fatigue your leg muscles and therefore the reaction is not as great due to the tired muscles. 
3. Blink Reflex
1. Recap: Have your partner hold up a sheet of plastic wrap in front of their face. Throw a cotton ball at them. Observe how they react.
2. Claim: People blink when objects are thrown at their face.
3. Evidence: My partner blinked when the cotton ball was thrown at her face. Here is a video of how one reacts to objects being thrown at them (video courtesy of Jennifer Poo).
4. Reasoning: She blinked because the reflex of blinking is to protect one's eyes from harm. Therefore, when the cotton ball was thrown at her, her body believed that something was coming at her, causing her to blink.
4. Babe, what's your sign?
1. Recap: Run a pen firmly down one partner's foot. Observe what your partner's response was.
2. Claim: Toes should clench together, if not, one might have nerve damage.
3. Evidence: When the pen was run down the my foot, my toes curl instead of spreading out. 
4. Reasoning: If there is something you're about to step on, you're foot will try to curl away from the item instead of spreading your toes out and possibly stepping on the potentially dangerous item.
5. How fast are you?
1. Hold a yard stick above your partner's hand. Warn them within 5 seconds of dropping the stick. Drop it, and take down the measurement where they catch it. Convert the measurement to time and average the times. Repeat process 3 times, then do it again except while texting.
2. Claim: One will catch the yard stick faster while not texting.
3. Evidence: My reflex time increased when I was texting compared to when I was solely focused on catching the yard stick. My average reaction time went from .17 seconds to .40 seconds, which is a huge increase.  
4. Reasoning: I believe that my reaction time increased because I was not as focused on catching the yard stick when I was texting. Personally, I have terrible reflexes so this lab also confirmed that for me. But the obviously, texting slow down reaction times since the brain is not focused solely on catching the yard stick. This means that if one is texting while driving then one's reaction rate will increasing marginally, which could be the few milliseconds needed to react in a crash.