fart vs physiological reaction

fart and physiological reaction both are nouns.

Word	Noun	Adjective	Verb	Adverb
fart	Yes	No	Yes	No
physiological reaction	Yes	No	No	No

As nouns, physiological reaction is a hypernym of fart; that is, physiological reaction is a word with a broader meaning than fart:

fart: a reflex that expels intestinal gas through the anus
physiological reaction: an automatic instinctive unlearned reaction to a stimulus

fart (noun)	physiological reaction (noun)
a reflex that expels intestinal gas through the anus	an automatic instinctive unlearned reaction to a stimulus

fart (verb)	physiological reaction (verb)
expel intestinal gases through the anus