instinctive reflex vs physiological reaction

instinctive reflex and physiological reaction both are nouns.

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

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

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

Other synonyms of instinctive reflex include inborn reflex, innate reflex, reflex, reflex action, reflex response, unconditioned reflex.

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