Reflex lab

In this lab we experimented with different reflexes. In our lecture we learned that with reflexes, nerve impulses do not go to the brain.

For the photopupillary reflex we expected the dilated pupil to shrink in size when exposed to slight. We did not see a change in size and that is probably because I did not cover my eye long enough for it to dilate. I think humans developed this reflex of a dilating and shrinking pupil so they can see when it´s dark or light outside.

The Knee-jerk reflex is when the leg kicks as it is tapped below the knee. When I tapped below my lab partner´s knee, his leg kicked outwards. This proves the knee-jerk reflex because when tapping below the knee causes the thigh muscle to stretch. After he exercised, the reflex was less vigorous. This is probably because his muscles were fatigued.

In the blink reflex my lab partner held a transparent piece of saran rap in front of his face while I threw a cotton ball at him. He blinking, therefore confirming the blink reflex. I think humans have this reflex to protect their eyes from harm.

The Babinski´s sign test was a little confusing but the reflex was testing nerve damage. According to Babinski´s sign, I do not have nerve damage. When a pen was dragged along the sole of my foot up towards my big toe, my foot flexed. Since I did not show Babinski´s sign, I do not have nerve damage.

Finally, we tested reaction time. We did two experiments; in the first one we made sure the person was paying attention and in the second experiment the person was texting. Our reaction rates were faster when we were not texting. When I was not texting, my reaction time was 0.35 sec. When I was texting, my reaction time was 0.5 sec. This shows that it is very dangerous to text and drive because our reaction times are slower when we are texting.