<prompt> Posterior wall and floor of external auditory canal is supplied by-Vidian nerveArnold nerveFacial nerveLesserpetrosal nerve  <response>: Ans. is b i.e., Arnold nerve Nerve supply of pinna auricle and external auditory canal1 Pinna auricle Lateral surface:- Great auricular nerve C2, C3, auricular branch of vagus Arnolds nerve, facialnerve, auriculotemporal nerve- Medial surface:- Great auricular nerve, auricular branch of vagus ArnokTs nerve, facialnerve, lesser occipital nerve.2 External auditory canal Anterior wall and roof:- auriculotemporal nerve. Posterior wall and floor:- auricular branch of vagus. Posterior wall not floor also receives sensory fibresfrom facial nerve through auricular branch of vagus, therefore hypoesthesia of posterior meatal wall is seen in facial nerve injury - Hitzelbergers sign. 