An apparatus for insertion into a body cavity, comprising: an elongated body comprising a plurality of articulatable segments, a proximal end, and a steerable distal portion; a plurality of tendons attached to at least a majority of the segments and extending from the segments to the proximal end of the elongated body, actuation of the tendons causing actuation of the segments; an external control unit including a plurality of actuators; a connector interface holding proximal connector ends of the tendons in an organized array; a receiving interface (956, 974) complementary to the connector interface and provided on the external control unit, the receiving interface holding distal connector ends of the actuators, the distal connector ends being complementary to the proximal connector ends of the tendons to engage and transmit force to the proximal connector ends of the tendons; and a quick-release mechanism for respectively coupling the distal connector ends of each of the plurality of actuators to the proximal connector ends of each of the plurality of tendons, the quick-release mechanism comprising the connector interface and the receiving interface, each of the connector interface and the receiving interface comprising complementary structures and arranged to mate with one another to engage the distal connector ends of the actuators with the proximal connector ends of the tendons to enable each actuator to apply force directly to the proximal end of a specific respective tendon such that each of the plurality of tendons is individually actuatable by a respective actuator separately from the remaining tendons; wherein when the distal end assumes a selected curve, the selected curve is propagatable along the elongated body by the plurality of actuators, under control of the external control unit, each actuating a respective tendon of the plurality of tendons to selectively actuate the segments. an elongated body comprising a plurality of articulatable segments, a proximal end, and a steerable distal portion; a plurality of tendons attached to at least a majority of the segments and extending from the segments to the proximal end of the elongated body, actuation of the tendons causing actuation of the segments; an external control unit including a plurality of actuators; a connector interface holding proximal connector ends of the tendons in an organized array; a receiving interface (956, 974) complementary to the connector interface and provided on the external control unit, the receiving interface holding distal connector ends of the actuators, the distal connector ends being complementary to the proximal connector ends of the tendons to engage and transmit force to the proximal connector ends of the tendons; and a quick-release mechanism for respectively coupling the distal connector ends of each of the plurality of actuators to the proximal connector ends of each of the plurality of tendons, the quick-release mechanism comprising the connector interface and the receiving interface, each of the connector interface and the receiving interface comprising complementary structures and arranged to mate with one another to engage the distal connector ends of the actuators with the proximal connector ends of the tendons to enable each actuator to apply force directly to the proximal end of a specific respective tendon such that each of the plurality of tendons is individually actuatable by a respective actuator separately from the remaining tendons; wherein when the distal end assumes a selected curve, the selected curve is propagatable along the elongated body by the plurality of actuators, under control of the external control unit, each actuating a respective tendon of the plurality of tendons to selectively actuate the segments.