duct, epithelial duct, canal, channel - a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance; "the tear duct was obstructed"; "the alimentary canal"; "poison is released through a channel in the snake's fangs"

spinal column, spine, vertebral column, rachis, backbone, back - the series of vertebrae forming the axis of the skeleton and protecting the spinal cord; "the fall broke his back"