Malleolar folds – separating folds between pars tensa and pars flaccida.
Notch of rivinus – Superiorly tympanic bone deficient area where pars flaccida completes its margins.
Middle fibrous layer of tympanic membrane (in pars tensa only) – fibres arranged in radial, circular and parabolic pattern.
Nerve supply of TM – auriculotemporal (outer anterior half), arnold’s (outer posterior half), jacobson’s (inner mucosa).
Myringitis bullosa – viral infection of TM, multiple vesicles on TM, self-limiting.
Arnold nerve = auricular branch of vagus (X cranial nerve).
Jacobson nerve = tympanic branch of glossopharyngeal (X cranial nerve) – supplies middle ear mucosa. Referred otalgia from tonsillitis / pharyngitis / Cancers of base of tongue is due to this nerve common innervation (ear & pharynx).
Nerve of wrisberg = nervus intermedius = sensory branch of facial nerve supplying posterior meatal wall.
Hitselberger sign – compression of nervus intermedius in internal auditory canal by acoustic neuroma causing hypoesthesia of its supplying posterior meatal wall in EAC.