Gag reflex and Reflex action

Gag reflex noun - Normal reflex consisting of retching; may be produced by touching the soft palate in the back of the mouth.

Reflex action and gag reflex are semantically related. In some cases you can use "Reflex action" instead a noun phrase "Gag reflex".

Reflex action noun - An automatic instinctive unlearned reaction to a stimulus.

Gag reflex and reflex action are semantically related. Sometimes you can replace phrase "Gag reflex" with "Reflex action", this phrases are similar.