The story
- Proto-Indo-European*bʰuH-
- Proto-Indo-European*bʰuHyéti
- Ancient Greekφῠ́ω (phŭ́ō)
- Ancient Greekφῠ́σῐς (phŭ́sĭs)
- Englishphysio-
- Proto-Indo-European*leǵ-
- Proto-Indo-European*lóǵos
- Proto-Hellenic*lógos
- Ancient Greekλόγος (lógos)
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Latinphysiologicus
- English todayphysiological
Either from physio- + -logical (equivalent to physiology + -ical) or Latin physiologicus + -al.
Etymology from Wiktionary, CC BY-SA 4.0.