On the fourth cranial nerve.
D006801:Humans; D009801:Oculomotor Muscles / Q000294:innervation / Q000503:physiopathology; D009915:Orbit / Q000294:innervation; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology; D014321:Trochlear Nerve / Q000503:physiopathology*