reflex action vs physiological reaction

reflex action and physiological reaction both are nouns.

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

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

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

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