Why do we have two enlargements in Cervical cord Cervical the spinal cord? Thoracic cord The increased numbers of Thoracic motor and sensory neurons to provide the origins of the nerves of upper and lower extremities. ord Lumba Spinal nervesWhy do we have two enlargements in the spinal cord? The increased numbers of motor and sensory neurons to provide the origins of the nerves of upper and lower extremities