trachealis
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tra·che·a·lis .trā-kē-'ā-ləs, -'al-əs n,
pl -a·les -'ā-(.)lēz, -'al-(.)ēz a muscle associated with the trachea that in humans consists of smooth muscle fibers extending transversely between the ends of the tracheal rings and the intervals between them at the back of the trachea
Medical dictionary.
2011.