bronchial tube vs bronchus

bronchial tube and bronchus both are nouns.

Word	Noun	Adjective	Verb	Adverb
bronchial tube	Yes	No	No	No
bronchus	Yes	No	No	No

As nouns, bronchial tube and bronchus are synonyms defined as:

bronchial tube and bronchus: either of the two main branches of the trachea

bronchial tube (noun)	bronchus (noun)
either of the two main branches of the trachea	either of the two main branches of the trachea