Reflexes Lab

In this lab we tested our reflexes by doing a series of tests. For the first test to test our photopupillalry reflex, we covered one of our eyes and shined a flashlight over the hand, so when we removed the hand we watched the pupil to see it change in size.  The autonomic reflex is responsible for regulating the changes in pupil size.  We learned that when the intensity of light entering the eye increases, the photopupillary reflex is triggered and it stimulates the cilliary body to contract. Next, we hit our knee to see if it would kick out to test our monosynaptic reflex. When you hit below the knee, it causes the thigh muscle to stretch.  The knee jerk reflex has two neuron reflex arcs, it goes from sensory neuron to spinal cord to motor neuron to the knee.  For the next reflex, we tested the blink reflex by having someone stand with a piece of saran wrap in front of their face and have another person throw a cotton ball at it and observe if the person blinks.  The blink reflex is important because it protects the eye from things that could damage it.  To test our plantar reflex, we dragged a pen up the sole of the foot from heel to the base of the big toe, and observed if the toes moved closer together or further apart, and for us they moved closer together which is normal.  The toes might move further away if there is nerve damage, this could be a sign that the nervous system isn't completely myelinated. By dropping a ruler, having someone catch it and recording the number of inches the ruler dropped we could calculate the amount of time it took for us to activate our visual and motor reflexes.  We did the trial 3 times and took an average, then tried it again but while the ruler was being dropped you had to write a text with one hand and catch the ruler with the other hand.  By adding in that we had to type out a text, it slowed down our reaction time and made it harder for us to respond and catch the ruler.

Eye when first exposed to the light

eye after exposed to light
 pupil got smaller