An example of this arc is the knee jerk reflex where the thigh muscle contracts following the tapping of the knee tendon with a hammer. The key point is that the brain is not involved. This sensory system detects many different types of sensation that include pain, touch, and temperature. This information is relayed to the spinal cord by the afferent neuron. The reflex response, however, does return after a few months.
Nobody really knows why the symptom of spinal shock occurs.
Image of the components that make up the Brain Stem. Frequency of spinal cord injury by sex. Males are 5 times as likely to suffer injury. Frequency of injuries caused by sports.