gulp vs physiological reaction

gulp and physiological reaction both are nouns.

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

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

gulp: a spasmodic reflex of the throat made as if in swallowing
physiological reaction: an automatic instinctive unlearned reaction to a stimulus

gulp (noun)	physiological reaction (noun)
a large and hurried swallow	an automatic instinctive unlearned reaction to a stimulus
a spasmodic reflex of the throat made as if in swallowing

gulp (verb)	physiological reaction (verb)
utter or make a noise, as when swallowing too quickly
to swallow hurriedly or greedily or in one draught