Reflexes Lab

Some motions are automatic, things we do without thinking about, and can't stop even if we want to- like blinking if something is town at our face. These are called reflexes, and they work by sending a signal to the spine, which sends a signal directly back to the muscle, bypassing the brain entirely. In this lab, we tested some of our different reflexes.
First, we tested our photo pupillary reflex- the reflex that controls the contraction of our pupils in response to light. We covered one eye, then shined a light in it and watched, and we saw the pupil constrict. Humans have probably evolved this reflex to prevent us from being blinded by bright lights.

After that, we tested our patellar reflex, which is the one doctors test when you go in for a physical. It causes the lower leg to suddenly kick out in response to a sharp tap to a spot under the knee. It is sometimes hard to find, but my lab partner and I were able to find it, tapping the knee in the right place and causing the lower leg to suddenly kick out. I don't know exactly why this happens, but I think it could be some sort of defense mechanism.

We also tested our blink reflex by throwing a cotton ball at each other's faces while stretching a piece of plastic in front of our eyes to protect them. Obviously, we both blinked. This reflex evolved in order to protect our eyes from harm.

After that, we tested the reflex in our foot, drawing an object across the bottom of our feet and making our toes curl. This probably also evolved in order to protect our feet.

Finally, we tested our reaction time by having our partner drop a yardstick and catching it, then figuring out our response time. We did this both normally and while texting, and my average response time was slower by 0.03 seconds when texting, increasing from 0.27 to 0.3 seconds.