Vestibulo Cochlear App

Vestibulo-cochlear apparatus

Vestibulo-cochlear apparatus Ageng BrahmadhiVestibulo-cochlear apparatusDual sensory function stato-acoustic systemParts:the external ear, the middle ear and the internal ear

External earreception of sound wavesIt consists of the Auricle (pinna),External auditory meatus/ Meatus acusticus externus (canal)Membrana tympani

Pinnairregularly shaped plate of elastic cartilage covered by thin skin The cartilage of the pinna is continuous with the cartilage lining the cartilaginous portion of the external auditory meatus. external auditory meatus is the canal that extends from the pinna to the external surface of the tympanic membranewith skin containing hair follicles, sebaceous glands, and modified sweat glands known as ceruminous glands cerumentympanic membrane covers the deepest end of the external auditory meatusExternal surface : covered by a thin epidermis derived from ectodermInternal surface : simple squamous to cuboidal epithelium derived from endodermCollagen fibers, elastic fibers, and fibroblasts, is interposed between the two epithelial layers. Derived from mesodermMiddle Ear tympanic cavitylined by simple squamous epitheliumpseudostratified ciliated columnar epithelium as it approaches the auditory tube -- eustachian tubeOssicula auditiva (maleus, incus, stapes)the medial wall of the tympanic oval window (Fenestra vestibuli/tingkap oval ) and the round window (Fenestra cochleare/tingkap bulat)the tensor tympani and the stapedius, modulate movements of the tympanic membrane and the bony ossicles

Inner Earbony labyrinthmembranous labyrinth

Bony Labyrinthhas three components: the semicircular canals, the vestibule, and the cochlea.lined with endosteumfilled with perilymph

The central region Vestibulewall contains the oval window (fenestra vestibuli) and round window (fenestra cochleae)Three semicircular canals (superior, posterior, and lateral). Enlargement ampulaCochlea like a snail shell, two and one-half times around a central bony column, the modiolusThe modiolus projects into the spiraled cochlea with a shelf of bone called the osseous spiral lamina

Membranous Labyrinth Inside bony labyrinthfilled with endolymph possesses the following specialized areas: the saccule and utricle, the semicircular ducts, and the cochlear duct. Saccule and Utricle The saccule and utricle, sac-like structures lying in the vestibule, contain neuroepithelial cells that are specialized to sense position of the head and linear movement.Specialized regions of the saccule and utricle receptormacula of the saccule and the macula of the utricleThe maculae are thickened areas of the epithelium, composed of neuroepithelial cells, type I and type II hair cells Type I hair cells are plump cells with a rounded base that narrows toward the neck Type II hair cells are similar to type I hair cells with regard to the stereocilia and kinocilium, but their shape is more columnar The stereocilia of the neuroepithelial hair cells are covered by and embedded in a thick, gelatinous glycoprotein mass, the otolithic membraneThe surface region of this membrane contains otoliths or otoconia

Semicircular Ducts Bodycontains an expanded region, the ampulla, where specialized receptors (neuroepithelial hair cells) sense linear and angular movement.neuroepithelial cells, also known as type I and type II hair cells, exhibit the same morphology as the hair cells of the maculae The cupula, a gelatinous glycoprotein mass overlying the cristae ampulares, is similar to the otolithic membrane in structure and function, but it is cone-shaped and does not contain otoliths

Ampula kanalis semisirkularis

Krista ampullarisPergerakan cupula akibat perubahan posisi kepala menggerakkan sel rambut pada cupula menggetarkan silia pada sel rambut membuka kanal ion K depolarisasi akhiran saraf pada sel-sel rambut.

Percepatan gerak melingkar cairan duktus semisirkularis mengalir merangsang kupula pada krista ampularis stereosilia pada sel sensoris badan sel sarafDuktus semisirkularis : percepatan angular.Makula utrikuli & sakuli : percepatan linear.Alat vestibular:persepsi gerakanorientasi dalam ruanganmempertahankan keseimbangan badan.FUNGSI VESTIBULARVestibular sensory receptors

Hair cells transduction

Cochlear Duct and Organ of Corti 3 chamber of Cochlear Duct :skala vestibuli (superior) : perilimfe skala timpani (inferior) : perilimfeskala media (duktus koklearis) : endolimfeDuctus cochlearisroof: membrana Reissner/vestibularisEpitel squamous simpleks + membrana basalisBase : membrana basilaris

Gombang suara osikel perbedaan luas membrana timpani dan landasan kaki stapes penerusan gerak dinamis secara efisien udara ke cairan telinga dalam menggetarkan membrana tectoria menggetarkan sel rambut membuka kanal ion K depolarisasiFUNGSI AUDITORIUS

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