An instrument having a flexible and elongated body includes at least a lumen and a flex member disposed within the lumen. The flex member may be capable of providing steering control to a first portion of the elongate body while providing load bearing support to a second portion of the elongate body. A pull wire may be disposed within the flex member, and at least a distal portion of the pull wire may be coupled to the elongate body and a proximal portion of the pull wire may be operatively coupled to a control unit. The control unit may be coupled to a proximal portion of the elongate body.