2-Minute Neuroscience: Knee-jerk Reflex

In this video, I discuss the knee-jerk reflex. The knee-jerk reflex, also known as the patellar reflex, is a simple reflex that causes the contraction of the quadriceps muscle when the patellar tendon is stretched. I describe the course of the reflex arc from muscle spindles in the quadriceps muscle to motor neurons that cause movement of the leg. I also discuss the role of inhibitory interneurons in inhibiting the movement of the hamstring muscle, which allows the quadriceps contraction to be unopposed.