physiological reaction vs reflex

physiological reaction and reflex both are nouns.

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

As nouns, physiological reaction and reflex are synonyms defined as:

physiological reaction and reflex: an automatic instinctive unlearned reaction to a stimulus

physiological reaction (noun)	reflex (noun)
an automatic instinctive unlearned reaction to a stimulus	an automatic instinctive unlearned reaction to a stimulus

physiological reaction (adjective)	reflex (adjective)
	without volition or conscious control