structure vs tube

Other hyponyms of structure include layer, apodeme, caliculus, calycle, calyculus, tooth, pad, branchial cleft, gill cleft, gill slit, branchial arch, gill arch, gill bar, peristome, syrinx, bulb, carina, cauda, chiasm, chiasma, decussation, cingulum, concha, filament, filum, germ, infundibulum, interstice, landmark, limbus, rib, blade, radicle, plexus, rete, tube-shaped structure, passage, passageway, fundus, funiculus, head, bodily cavity, cavity, cavum, root, capsule, uvea, lens nucleus, nucleus, membranous labyrinth, bony labyrinth, osseous labyrinth, glans, alveolar bed, valve, vascular structure, lacrimal apparatus, cytoskeleton, nucleolar organiser, nucleolar organizer, nucleolus organiser, nucleolus organizer, centromere, kinetochore, aster, neural structure, fold, plica, convolution, gyrus, cartilaginous structure, ball, plate, horny structure, unguis, skeletal structure, costa, head, bridge, rotator cuff, cornu, corona, receptor, zona, zone.