The invention relates to a longitudinally-steerable structure, comprising essentially longitudinal actuators made from shape memory alloy, Peltier effect elements with N and P doping and electrical control device. The above is characterized in that the actuators are arranged in pairs in an antagonistic manner, each actuator being connected at the ends thereof with a Peltier effect element with N doping and a Peltier effect element with P doping respectively. The invention further relates to an endoscope comprising at least one such structure.