The purpose of this project is to find out compare reflexes between different people. The knee jerk reflex is one that you may have had tested at a check up at the doctor's office. In this test, the doctor hits your knee at a spot just below your knee cap and your leg kicks out. The leg will kick out immediately (if you hit the right place). The knee jerk reflex (seen in the figure to the right) is called a monosynaptic reflex because there is only one synapse in the circuit needed to complete the reflex. It only takes about 50 milliseconds between the tap and the start of the leg kick. That is fast! The tap below the knee causes the thigh muscle to stretch. Information is then sent to the spinal cord. After one synapse in the ventral horn of the spinal cord, the information is sent back out to the muscle...and there you have the reflex.