There is no usage guidance for this tag … yet!
Usage guidance, also known as a tag wiki excerpt, is a short blurb that describes when and why a tag should be used on this site specifically.
Physiology is the study of how organisms, organs, cells, and biomolecules carry out the chemical or physical functions that exist in living systems. [Source: Wikipedia]
Questions should be on function, while the anatomy tag should be used for structural aspect questions.
Questions asking about mechanisms or the physiological processes behind a pathological condition should include the pathophysiology tag.
Questions asking about the electrical activities of the heart should include the cardiac-electrophysiology tag.