Ear Flashcards
6 Structures of Auricle
Helix (outer curvature) Antihelix (second curvature) Tragus (anterior thing that sticks back) Antitragus (lower thing that sticks up) Concha (curly part in middle) External auditory meatus (space b/w tragus/antitragus)
3 Nerves that Do Sensory Innervation Around Ear
Auriculotemporal branch of trigeminal (V3)
Great auricular
Lesser occipital
Blood Supply of External Ears (2)
Superficial temporal and posterior auricular a.s
Structural Support of Ear Canal (2)
Lateral third - cartilaginous
Medial 2/3 - canal in temporal bone
Ceruminous glands
Produce earwax
Sensory Innervation of Ear Canal (2)
Primarily auriculotemporal branch of trigeminal (V3)
Small portion by vagus (X) right by tympanic membrane - upset stomach from inner ear infection
2 Parts of Tympanic Membrane
Pars flaccida (loose, smaller part) and pars tensa (tense, main part)
4 Projections onto Surface of Tympanic Membrane
Anterior and posterior malleolar folds
Manubrium of malleus
Umbo (very end of malleus)
External Sensory Nerve Supply of Tympanic Membrane (2)
Auriculotemporal (V3) and Vagus (X)
Internal Sensory Nerve Supply of Tympanic Membrane
Glossopharyngeal n. (IX)
Middle Ear Ext. to Int. (4)
External acoustic meatus
Tympanic membrane
Tympanic cavity
Auditory tube
Function of auditory tube
Bring air from nasopharynx to equalize pressure on each side of tympanic membrane
Tensor tympani m. (2)
Innervated by V3 and runs to posterior side of tympanic membrane to tense it
3 Structures on Lateral Tympanic Cavity Wall
Tympanic membrane - malleus - incus
Epitympanic recess
Where malleus and incus reside
Internal Carotid A. Relation to Middle Ear
Runs right past tympanic cavity, can hear heartbeat in very quiet room
Chordatympani n.
Off of facial n. (VII) and runs b/w middle ear bones, so middle ear damage can damage that nerve
Stapedius m.
Tenses stapes
6 Contents of Medial Tympanic Cavity Wall
Oval window where fluid comes in Stapes Stapedius m. Round window where fluid exits Promontory - bulge from cochlea, with tympanic n. (IX) branches on it
One Reason Why Kids get more Ear Infections
Auditory tube much shorter
Auditory Tube Structural Support (2)
Cartilaginous in nasopharynx
Bony in middle ear
Reason for Auditory Muscles (Tensor tympani and stapedius m.s)
Protect ears from loud noises by tensing and preventing too much vibration - but need to hear loud sounds first (so gunshot can still deafen)
2 Nerves in Middle Ear Region
Chorda tympani branch of facial n. (VII)
Glossopharyngeal n. (IX)
2 Structures of Inner Ear (and functions + one other point)
Cochlea for hearing
Vestibular appartus for balance
Filled w/ endolymph