The knee jerk reflex is an example of a?

The knee jerk reflex is an example of a monosynaptic reflex. This means that the reflex arc involves only one synapse between the sensory neuron and the motor neuron. The sensory neuron detects the stretch in the quadriceps muscle and sends a signal to the spinal cord. The motor neuron then sends a signal back to the quadriceps muscle, causing it to contract and produce the knee jerk reflex.