Final answer:
A crossed-extensor reflex is a type of reflex that involves the activation of muscles on one side of the body in response to a painful stimulus on the other side of the body. It is an example of double reciprocal innervation.
Step-by-step explanation:
A crossed-extensor reflex is a type of reflex that involves the activation of muscles on one side of the body in response to a painful stimulus on the other side of the body. It is an example of double reciprocal innervation, where the muscles on one side are inhibited while the muscles on the other side are activated.