Source : Webster's Revised Unabridged Dictionary (1913)

Bronchial \Bron"chi*al\, a. [Cf. F. bronchial. See {Bronchia}.]
   (Anat.)
   Belonging to the bronchi and their ramifications in the
   lungs.

   {Bronchial arteries}, branches of the descending aorta,
      accompanying the bronchia in all their ramifications.

   {Bronchial cells}, the air cells terminating the bronchia.

   {Bronchial glands}, glands whose functions are unknown,
      seated along the bronchia.

   {Bronchial membrane}, the mucous membrane lining the
      bronchia.

   {Bronchial tube}, the bronchi, or the bronchia.

Source : WordNet®

bronchial tube
     n : either of the two main branches of the trachea [syn: {bronchus}]