Kanika Anatomy and Physiology: Reflex Lab

In this reflex lab, we tested different reflexes and saw their results. A reflex, as defined by Merriam- Webster, is "an automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to a nerve center and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness." Basically, a reflex is a response to stimuli which we respond to unconsciously. We began with testing the photopupillary reflex. This reflex occurs when the pupil is exposed to different amounts of light. When the eye is dark, the pupil opens up. As it is exposed to more and more amounts of light, the pupil constricts. We tested this by exposing one eye to no light for 2 minutes, and the opening it to a flashlight shined directly in the eye. We were able to see the pupil grow drastically smaller because the pupil was reacting to such a contrasting change in lighting. We then moved on to the knee jerk reflex. This reflex occurs because a stimulus hits the patellar tendon. We did see movement of the lower leg when the patellar tendon was hit. After completing 10 squats each, my partner and I tested our knee jerk reflex again. We were expecting to see a reduced movement in the leg, but we saw the extreme opposite; the leg jumped outwards. We believe this occurred because of increased circulation to the patellar tendon. Our third experiment was the blink reflex. This reflex protects us because whenever we feel like our eyes are in danger from something coming towards us fast, we blink to protect our eyes. In this experiment, we held seran wrap a few inches in front of our faces and our partners threw cotton balls at our eyes. These cotton balls wouldn't actually hit our eyes, but we did still see a blink reflex. This shows how overcautious our body is programmed to be. After this we tested our plantar reflexes. This reflex is an important neurological test. My partner had to take the cap of a pen and drag it from my heel all the way to the base of my big toe. My feet curled in. This shows that I did not show Babinski's sign, which means that there is no nerve damage in my foot. Someone with multiple sclerosis would show Babinski's sign because there is nerve damage in multiple sclerosis. Our final experiment tested how fast our hand-eye coordination was. My average time was .203 seconds while my partner's average time was .175 seconds. We expected our average response time to increase while we were multitasking while texting. The opposite happened. My average dropped to .160 seconds and my partner's dropped to .143 seconds. This was probably because we had practice catching the yardstick.