The Babinski reflex is a somatic reflex seen in infants. When the side of the foot is stroked, the toes spread apart. Another example of a somatic reflex is the ankle-jerk reflex, which causes the ankle to bend the foot towards the ground when the Achilles tendon is tapped.
Somatic reflexes are movements of body parts that result nearly instantly when a certain stimulus is delivered. Reflexes are able to occur so quickly because the stimuli that cause them are not processed in the brain. Rather, the nerve impulse generated by the stimulus is relayed only to the spinal cord. A motor nerve impulse, which signals for the muscles to react in a certain way, is then sent back from the spinal cord to the muscle.
Humans display many different reflexes. The biceps reflex causes the forearm to jerk when the biceps brachii is tapped with a hammer. The corneal reflex causes a person to blink when the cornea of the eye is touched, and the knee-jerk reflex causes the lower leg to kick outward when the patellar tendon just beneath the knee cap is struck. Blushing is another reflex; the face turns red when a person experiences embarrassment or shame.