AUDITORY SYSTEM: Anatomy, physiology and function Chunfu Dai,m.d&PhD Otolaryngology Department Fudan University
Outer Middle Inner Bor Stapes Semicircular Malleus Oval Concha window The ear is divided into three parts Vestibular Outer, Midd Cochlear and nner ear nerve Cochlea Each serves different Vestibule aspects of the Round window auditory sensation The outer ear is collects sound waves Pinna and directs them towards the middle External ear auditory meatus Outer/ Middle Inner collection transformation \transduction
The ear is divided into three parts: Outer, Middle, and Inner ear. Each serves different aspects of the auditory sensation. The outer ear is collects sound waves and directs them towards the middle ear Outer Middle Inner collection transformation transduction Outer Middle Inner
Sound waves in the ear canal vibrate Ear oSsicles is of rotation the ear drum oscillating the middle ear bones. Thus, the oscillations of the ear drum are conveyed to the oval window at the base of the cochlea tympanic Malleus Incus Stapes small force LARGE FORCE LARGE AMPLITUDE small amplitude Middle ear bones act an impedance matcher, enabling sound pressure waves in air to be introduced into the fluid-filled inner ear at the oval window. at the base of the cochlea Tympanic Round Base of stapes membrane window In oval window
Sound waves in the ear canal vibrate the ear drum, oscillating the middle ear bones. Thus, the oscillations of the ear drum are conveyed to the oval window at the base of the cochlea Middle ear bones act an impedance matcher, enabling sound pressure waves in air to be introduced into the fluid-filled inner ear at the oval window, at the base of the cochlea
The Inner ear is a bony labyrinth, and contains the cochlea and the vestibular system Cochlear Receptors -Cochlear nerve Semicircular A Membranous Utricle canals labyrinth within bony labyrinth Sacco le path of sound waves Scala vestibuli Cochlear duct (scala media Scala tympani Round window Oval window and stapes Vibration of the stapes at the oval window results in pressure waves that travel through the cochlear fluids until they reach the round window
Vibration of the stapes at the oval window results in pressure waves that travel through the cochlear fluids until they reach the round window The Inner ear is a bony labyrinth, and contains the cochlea and the vestibular system
The membranous labyrinth partitions the bony labyrinth of the cochlea into three chambers-the perilymphatic scala vestibuli and scala tympani; and the endolymphatic scala media. These fluids also extend into the vestibular labyrinth Vestibular Apical turn membrane Tectorial membrane Middle turn Vestibular duct Modiolus (scala vestibuli- contaIns From perilymph) Cochlear duct scala media- contains Basal endolymph) turn Organ of Corti Tympanic F。e tympani membrane s contains To round perilymph) window Temporal bone Spiral ganglion (petrous portion) Cochlear nerve Vestibulocochlear nerve(N VIll)
The membranous labyrinth partitions the bony labyrinth of the cochlea into three chambers – the perilymphatic scala vestibuli and scala tympani; and the endolymphatic scala media. These fluids also extend into the vestibular labyrinth