internal nostril vs choana

internal nostril and choana both are nouns.

Word	Noun	Adjective	Verb	Adverb
internal nostril	Yes	No	No	No
choana	Yes	No	No	No

As nouns, internal nostril and choana are synonyms defined as:

internal nostril and choana: either one of the two posterior openings at the back of the nasal cavity leading to the nasopharynx

Other synonyms of internal nostril include posterior nasal aperture.

internal nostril (noun)	choana (noun)
either one of the two posterior openings at the back of the nasal cavity leading to the nasopharynx	either one of the two posterior openings at the back of the nasal cavity leading to the nasopharynx