Auditory and balance apparatus Morphology and embryology Auris, is = Us, oton

Auditory and vestibular apparatus External ear (Auris externa) Middle ear (Auris media) Inner ear (Auris interna) = Organum vestibulo- cochleare

External ear (Auris externa) Earbolt (Auricula, Pinna) elastic cartilage External meatus (Meatus acusticus externus) Eardrum (Membrana tympanica, Myrinx)

Boltec Helix Antihelix Scapha Concha auriculae Tragus Antitragus crus, spina, cauda (tuberculum auriculare Darwini, apex auriculae) Antihelix crura, fossa triangularis Scapha Concha auriculae cymba, cavitas Tragus Antitragus Incisura intertragica Lobulus auriculae Posterior facet = negative ventral image Boltec

Ligaments: lig. auriculare ant., sup., post. Earbolt muscles - innervation: n. facialis External muscles = mimic mm. auriculares (ant., sup., inf.) m. temporoparietalis Proper muscles: rudimentary m. tragicus + antitragicus m. helicis major+minor m. obliquus + transversus auriculae, m. pyramidalis auriculae Cartilage: Cartilago auriculae - elastic Skin: back side free, ventrally firmly attached to perichondrium - othematom

Earbolt – supply Arteries: rr. auriculares ant.  a. temporalis superficialis a. auricularis post.  a. carotis externa Veins: v. jugularis ext. Lymph: n.l. parotidei, mastoidei Nerves: sensitive nn. auriculares ant. z n. auriculotemporalis (upper ventral 2/3) r. auricularis n. X. (concha) n. occipitalis minor (posterior up) n. auricularis magnus (down) motoric: n. VII.

Auditory canal (Meatus acusticus externus) porus acusticus externus  diagonally ventromed.  med.  again diagonally ventromed. (totally it converges forth 160º and it declines convex, length approx. 22 mm) external 2/3 – hyaloid cartilage open forth and down (incisurae Santorini), lamina tragi (forth) transition – narrowest place – foreign bodies !!! inner 1/3 – bony – incisura tympanica Rivini glandulae ceruminosae + sebaceae  ear wax (cerumen) – protection tragi (after 30. years of age) Skin attached to perichondrium – even small inflamation very painful !!! Anterior wall: relation to gl. parotis and art. temporomandibularis

Auditory canal (Meatus acusticus externus) supply Arteries: same as earboltc + a. auricularis prof.  a. maxillaris veins: v. temporalis superf., v. auricularis post. lymph: n.l. parotidei, mastoidei nerves: r. auricularis n.X. (posterior caudal part), n. auriculotemporalis  r. meatus ac. externi

Eardrum (Membrana tympanica, Myrinx)

Eardrum - composition Sulcus tympanicus, incisura tympanica Rivini 9x10 mm, thickness 0,1 mm, area 55 mm2 Anulus fribrocartilagineus External surface - weakened epidermis (ectoderm) Layer of thick collagenous tissue (mesenchyme) Inner surface – single layer cuboid epithelium (endoderm)

Eardrum Otoskopy umbo m.t. stria mallearis prominetia mallearis plica mallearis ant. + post. light reflex – trigonum Wilde (= cone of light, light reflex, Politzer's luminous cone) Bezold trias: prominentia + stria + reflex pars flaccida Shrapnelli (5 mm2) x pars tensa - Declination of eardrum (50º sagitally) - Inclinationof eardrum (45 º transverzally) Paracentesis: lower posterior quadrant

Eardrum - supply Arteries: a. auricularis prof.  a. maxillaris (external surface) aa. tympanicae (inner surface) Lymph: n.l. mastoidei, parotidei Nerves: a. auricularis n.X. n. auriculotemporalis  r. membranae tympani

Middle ear (Auris media) Middle ear cavity (Cavitas tympani) Middle ear ossicles (Ossicula aditus) Middle ear joints (Articulationes ossiculorum auditus) Middle ear muscles (Musculi ossiculorum auditus) Auditory tube (Tuba auditiva Eustachii)

Middle ear cavity (Cavitas tympani) paries tegmentalis paries jugularis: prominetia styloidea paries mastoideus: aditus ad antrum mastoideum, prominetia canalis semicircularis lat. + n. VII., eminetia pyramidalis, fossa incudis, apertura tympanica canaliculi chordae tympani, antrum mastoideum (cellulae m.) paries caroticus paries membranaceus paries labyrinthicus

Middle ear cavity paries labyrinthicus promontorium – first coil of cochlea sulcus promontorii – plexus tympanicus fenestra vestibuli (= ovalis) – basis of stapes + membrana stapedia fenestra cochlae (= rotunda) – membrana tympani secundaria

Middle ear cavity - supply Arteries: 4 aa. tympanicae, rr. caroticotympanici Veins: do plexus pterygoideus + sinus petrosus sup. Lymph: n.l. parotidei, mastoidei, cervicales profundi, retropharyngei Nerves: n. tympanicus (n.IX) – sensitive + parasympatic (ganglion tympanicum) r. pharyngeus (n.V2) for cartilagenous part of auditory tube nn. caroticotympanici (sympatic)

Middle ear ossicles (Ossicula aditus) Malleus (Malleus, Hammer) caput collum manubrium processus lateralis processus anterior

Middle ear ossicles (Ossicula aditus) Incus (Incus, Anvil) corpus crus longum processus lenticularis crus breve Stapes (Stapes, Stirrup) caput (collum) crus ant. + post. basis

Middle ear joints and ligaments (Articulationes ossiculorum auditus) art. incudomallearis (seddle bag) art. incudostapedia (ball shape like) syndesmosis tympanostapedialis otosclerosis – ossification Sometimes both joints are replaced by syndesmosis

Middle ear ligaments (Ligg. ossiculorum auditus) lig. mallei ant. (spina o.s.)+ sup.+ lat. lig. incudis sup. (fossa i.) + post. membrana stapedialis (fenestra vestibuli) lig. anulare stapediale (fenestra vestibuli) membrana tympani secundaria = secondary eardrum (fenestra cochleae)

Middle ear muscles m. tensor tympani m. stapedius semicanalis m.t.t. processus cochleariformis manubrium mallei innervation: n.V3 m. stapedius eminetia pyramidalis collum stapedis innervation: n.VII n. stapedius from pars mastoidea canalis nervi facialis

Middle ear Shape of sand clock – 2 mm narrow by eardrum (= mesotympanon) recessus epitympanicus (= atticus, epitympanon, epitympanum) – 6 mm recessus hypotympanicus (hypotympanon)– 4 mm plicae malleares ant., post. recessus ant., sup., post. (= Prussak space) plica chordae tympani, incudialis, stapedialis mucosa – single layer cuboid epithelium (different height) Cup cells only by opening of auditory tube !!! No glands !!!

Mastoid cavity (Antrum mastoideum) aditus ad antrum mastoideum cellulae mastoideae (development postnatally – 6th year) Type pneumatic Type diploic Type sclerotic cellulae tympanicae Flat 1 layer epithelium Close to sinus sigmoideus mastoidectomy

Auditory tube (Tuba auditiva) Tuba auditoria, tuba pharyngotympanica, salpinx, tuba Eustachii ostium tympanicum pars ossea (= semicanalis t.a.) – cellulae pneumaticae pars cartilaginea – cartilago (lamina med.+ lat., lamina membranacea) – under mucosa of tonsilla tubaria Gerlachi When enlarged tonsilla – lesion of ventilation (especially in kids)  inflammation of midlle ear cavity ostium pharyngeum (v úrovni meatus nasi inf.)

Auditory tube (Tuba auditiva)

Auditory tube (Tuba auditiva) Tuba auditoria, tuba pharyngotympanica, salpinx, tuba Eustachii Equilibrates pressure in pharynx and middle ear cavity thickness 2 mm, length 40 mm Transition of multilayer cylindrical epithelium in single layer cylindrical glandulae tubariae, cup cells – in cartilagenous part In kids more horizontal, shorter and wider Catetrization via nasal cavity

Auditory tube (Tuba auditiva) opening: m. tensor tympani m. salpingopharyngeus ? role of m. levator veli palatini not clear ? Ostmann adipose body

Inner ear (Auris interna) organum vestibulocochleare Bony labyrint (labyrinhtus osseus) forechamber (vestibulum) Semicircular canals (canales semicirculares) snail (cochlea) Inner acustic meatus (meatus acusticus internus) spatium perilymphaticum Membranous labyrinth (labyrinthus membranaceus) labyrinthus vestibularis labyrinthus cochlearis spatium endolymphaticum

Bony labyrinth (labyrinthus osseus) forechamber (vestibulum) recessus ellipticus (utricularis) apertura int. canaliculi vestibuli macula cribrosa superior crista vestibuli (pyramis vestibuli) recessus sphericus (saccularis) recessus cochlearis macula cribrosa media macula cribrosa inferior

Membranous labyrint (Labyrinthus membranaceus) Vestibular labyrinth (Labyrinhtus vestibularis) Utriculus (Elipsoid sac) Sacculus (Spherical sac) Ductus semicirculares (ampullae, crura) Ductus utriculosaccularis, reuniens Macula utriculi, sacculi – membrana statoconiorum (statoconium, striola) Crista ampullaris (sulcus, cupula)

Otolitic organs saculus et utriculus macula Hairy cells Supportive cells Gelatinous layer otoconia - crystals CaCO3 (otoliths – term for crystals in reptiles)

Bony labyrint (Labyrinhtus osseus) Semicircular canals (Canales semicirculares) Canalis semicircularis anterior (parallel to the pyramid axis) – eminentia arcuata Canalis semicircularis posterior (vertical) Canalis semicircularis lateralis (horizontal) – prominentia c.s.l. ampulla ossea (3) crus commune (ant. + post.), simplex (lat.)

Semicircular canals Membranous inside bony Receptors in ampulas cristae ampullares Crest 90° to canal axis cupula – gelatinous substance Hairy cells Support cells

Hairy cells Two types On apical surface: 1 kinocilia Several stereocilias bazally - synapse with nerve fibers

Bony labyrint (Labyrinhtus osseus) Snail (Cochlea) cupula, basis (2 a ¾ coil) scala vestibuli  helicotrema  scala tympani canalis spiralis cochleae lamina spiralis ossea lamella vestibularis + spiralis hamulus l.s. (end in helicotrema) lamina spiralis secundaria (only in first coil) apertura interna canaliculi cochleae

Bony labyrint (Labyrinhtus osseus) Snail (Cochlea) Spindle (Modiolus) basis lamina canalis spiralis – ganglion cochleare canales longitudinales – n. cochlearis

Bony labyrint (Labyrinhtus osseus) Inner acustic meatus (Meatus acusticus internus) porus acusticus internus fundus m.a.i. crista transversa + verticalis area n. VII. area cochlearis – tractus spiralis foraminosus area vestibularis sup. + inf. foramen singulare

Membranous labyrint (labyrinthus membranaceus) Labyrinhtus cochlearis scala media = ductus cochlearis paries vestibularis: membrana vestibularis Reissneri paries externus: stria vascularis, prominentia spiralis, vas prominens, lig. spirale paries tympanicus (= membrana spiralis): crista basilaris, lamina basilaris, vas spirale limbus spiralis: labium limbi tympanici, labium limbi vestibularis, (dentes acustici) membrana tectoria Organum spirale Corti membrana reticularis, sulcus spiralis internus + externus

Snail (Cochlea)

Scala media Contain endolymph on lamina basilaris is Corti organ Covered by membrana tectoria Bony lamina spiralis ligamentum spirale

Corti organ (Organum spirale) Hairy cells outer (3-4 rows) and inner (1 row) On surface stereocilia Apices sank inside membrana tectoria Between them Nuele space Supportive cells pillars (Cortiho) – border inner tunnel phalangeal (Deiters) – cover hairy cells Outer supportive – cylindrical Hensen and cuboid Claudius

Endolymph and perilymph Endolymph: similar to intracellular fluid stria vascularis  scala media  ductus endolymphaticus  saccus endolymphaticus (blind)  veins Perilymph: similar to CSF canalicus cochleae connected with subarachnoid space

Inner ear – blood supply Arteries: a. basilaris  a. inf. ant. cerebelli  a. labyrinthi Veins: vv. labyrinthi  sinus petrosus inf. v. aqueductus vestibuli, v. aqueductus cochleae Lymph: replaced by endolymph and perilymph

Inner ear - nerves Nervus vestibularis – ggl. vestibulare Scarpae pars superior n. utriculoampullaris pars inferior n. saccularis n. ampullaris posterior Nervus cochlearis – ggl. cochleare Corti !!! Bipolar neurons !!!

VIII. - Nervus vestibulocochlearis examination Tuning fork exams (Rinné, Weber, Schwabach) Examination of nystagmus (9 directions acc to Hering) Romberg – standing and close eyes Hautant – sitting and arms rising forward Unterberger – close eyes and walking on spot 30s

VIII. - Nervus vestibulocochlearis irritation / palsy Lesion of hearing (= hypacusis  anacusis ) deafness (= surditas) Ear lisps (= tinnitus) – humming, whistling, ringing… giddiness (= vertigo) By will not affectable eyeball movements (= nystagmus) Slow component – stronger side pushes weaker side Fast component – compensatory movement back – according to it is described direction of nystagmua Defects of gait and walking (= ataxie)

Auditory path I. Projection → Ascending → Sensory 4 – neuronal Crossed as well as not crossed 1. neuron: Bipolar cell in ganglion cochleare Corti in shape of spiral  n. cochlearis  n. VIII  tract divides into 2 parts into nuclei cochleares ant. + post.

Auditory path II. 2. neuron: pons Cells in nucleus cochlearis posterior (depth of tones) et anterior (intenzity of tones) – separated by pedunculus cerebellaris inferior  crossing  lemniscus lateralis  colliculus inferior Side tract: nucleus olivaris superior ( contralaterally is inhibited from ncl. v corpus trapezoideum)  estimation of space orientation of hearing

Auditory path

Auditory path III. 3. neuron: mesencephalon cells in colliculus inferior  brachium coll.inf. tonotopic organization commissura colliculi inferioris 4. neuron: diencephalon - metathalamus cells in corpus geniculatum mediale  lobus temporalis - gyrus temporalis transversus Heschli, area 41, 42

Auditory path – 3D

Vestibular path I. Projection → Ascending → Sensory 3-neuronal, crossed 1. neuron: bipolar cell ganglion vestibulare Scarpae  n. vestibularis  n. VIII Part of fibers runs as tractus vestibulocerebellaris directus w/o interconnection into cerebellum 2. neuron: cells nuclei vestibulares pontis  axons into different structures

Vestibular path II. – where to? Cerebral cortex cerebellum RF → facilitatory descending system spine Nuclei of eyeball moving muscles Via paramedial pontine RF reflex head-eyeball

Vestibular path III. – into cortex 3. neuron: cells nuclei ventrales thalami  cerebral cortex lobus parietalis - gyrus postcentralis (area 2) – primary cortex parieto-inzular cortex (gyrus insularis longus) + lobus temporalis - gyrus temporalis transversus Heschli (area 41,42)

Vestibular path III. – into cerebellum Tractus vestibulocerebellaris directus vestibulum  corpus juxtarestiforme (v PCI)  nodulus + uvula (ipsilat.) Tractus vestibulocerebellaris indirectus vestibulum  ncl. vestibulares  corpus juxtarestiforme (v PCI)  lobulus flocclulonodularis + vermis (bilat.)

Vestibular path III. – into spine Ncl. fastigii cerebelli  ncl. vestibularis lat. Deitersi (bilat.)  tr. vestibulospinalis lateralis  alfa + gama-motoneurons of extensors Ncl. vestibularis medialis + inferior  fasciculus longitudinalis medialis  interneurons (+ and -) in cervica spine reflex head-eye

Examination otoscopy, otomicroscopy – tympanice membrane paracentesis, gromets Tuning fork examinations Vestibuloocular reflex – nystagmus vestibulospinal reflex (Romberg, Unterberger test) X-ray (projection Stenvers – meatus acusticus intenrus, Schüller – proc. mastoideus), CT, angiography audiometry BER/BERA (ERA, AEP, ABR) otoacustic emision (from external hairy cells) nystagmus – ENG (PENG), calory test

Symptoms and ilnesses Eye pain = otalgia giddiness = vertigo humming / whistling = tinnitus nystagmus = fast synkinetic movements Cloth ears - hypacusis deafness = surditas morbus Menière – ionic dysbalance Aterosclerosis of a. lybyrinthi meningitis – most common reason for acquired deafness Treatment: vazodilatation

Development of auditory and vestibular system 3 sources + nerve fibers 1. branchial arch, cleft and membrane Mezenchyme of 1st and 2nd branchial arch Surface ectoderrm of the head Fibers from mezencephalon

Development of external eae meatus acusticus externus 1st branchial cleft After delivery short (danger of lesion) pinna 6 auricular tubercles (mezenchyme) Mostly 2nd branchial arch (but also 1st) appendices preauriculares

Development of external ear

Development of middle ear 1st branchial exagination tuba auditiva et cavum tympani 1. branchial arch malleus, incus lig. mallei anterius m. tensor tympani 2. branchial arch stapes m. stapedius

Development of middle ear antrum mastoideum Are not present cellulae mastoideae after delivery Appears in 2nd year Finished pneumatization cca in 6th year

Development of membrana tympani Outer epithelium from 1st branchial cleft Inner epithelium from 1st branchial exagination mezenchyme of 1st and 2nd branchial arch

Development of inner ear Start at 4th week - otic placode (ektoderm) Auditory pit Auditory sac (otocyst) Extension for ductus + saccus endolymphaticus Dorzal part utricular Ventral part saccular

Development of inner ear From utricular part Discoid extensions - ductus semicirculares Widening into ampula and origin of crests From saccular part divertikulum ductus cochlearis (convoluted) Origin of ductus reuniens Corti organ (from the wall of d. cochlearis) Origin of ganglion spirale

Development of inner ear Surrounding mezenchyme changes into cartillagenous capsula otica There appears cavities and thus originate perilymphatic spaces in 20. - 22. week cartillagenous model ossifies

Casuistic 1 male, 28 years Returned from vacation in Egypt otalgia 3 days Pain during palpation objective examination: palpatory sensitive tragus otoscopy: oedematic and reddish auditory canal with white cellular detrite

Casuistic 1 - diagnosis otitis externa Ilness of summer monthes and swimming complications: especially in DM  perichondritis or destruction of temporal bone

Casuistic 2 female, 3 years In the night burning pain of right ear, crying, cannot ease, 2 days runny nose In the waiting room vomiting temperature 38,3°C otoscopy: tympanic membrane reddish, smeared, protruding backside

Casuistic 2 - diagnosis otitis media acuta l. dx. treatment: paracentesis complications: perforation of tympanic membrane mastoiditis  trombosis of sinus sigmoideus labyrinthitis (chronic otitis media) grometa

Casuistic 3 female, 34 let Pressure in left ear, sudden cloth ear, humming tinnitus, rotatory vertigo, vomitus Vertigo disappeared, the rest is still there Objective examination: harmonic vestibular events (= dominance of on labyrinthus) audiometry: perceptive cloth ear apicocochlearly treatment: vazodilatation

Cazuistic 3 - diagnosis Menièr ilness hydrops of the labyrinth Mont after patient returns with the same problems dif.dg.: circulatory problems, aterosclerosis, sclerosis multiplex, neurinom of the n. VIII