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Special Senses 1632736664492 - Coggle Diagram

- - - - 1.Outer ear
        
        auditory canal
        
        Has numerous ceruminous glands that produce cerumin, and together with hair follicles they catch dust, bacteria and particles . It continues from the auricle to the ear drum. Sound moves in this canal to the eardrum
        
        Tympanic membrane(eadrum)
        
        Transparent membrane, super sensitive to the vibrations of the ear.It separates the outer ear to the middle ear. This is the first structure impacted by sound, it then vibrates thereby amplifying the sound to the middle ear
        
        auricle(pina)
        
        visible part of the ear that projects from the side of the head.This is the part where sound is first collected , When Michael heard the loud noise , most of the sound was collected through the pinna and channelled to the auditory canal
      - 2.Middle ear( Tympanic cavity) Irregular shaped air filled cavity within the temporal bone,lined with cuboidal epethelium
        
        Auditory tube(Eustachian tube) hollow passage way connecting middle ear to the nasopharynx.
        
        Malleus : hammer-shaped bone.sound moves from the ear drum to the malleus then goes to the incus
        
        Incus-This is the anvil shaped bone .Receives sound from the malleus and transfers it the the stapes.
        
        Stapes.- mideal shaped stirup bone, when it vibrates it hits the oval window in the inner ear.
        
        The Ossicles : These increase or amplify sound received from the eardrumand transfer it to the inner ear.They increase the pressure of sound about 20 times
      - 3.Inner ear.It consists of a bony structure.Sound waves from the middle ear are changed to electrical signals(nerve impulses)This allows the brain to hear and understand sounds.
        
        vestibule
        
        autricle and saccule
        
        important for balance
        
        Cochlea(snail shaped)
        
        Scala vestibuli (contains perilymph)
        
        originates from the oval window, where the footplate of the stapes rocks to and fro setting up fluid waves.
        
        Scala media(cochlear duct) most pressure of the waves is transmitted here., causing a corresponding wave motion in the endolymph resulting in the vibration of the basilar membrane and stimulation of the auditory receptors
        
        This is an extension of the membranous labyrinth.it has hair cells which contain auditory receptors, they form the spiral organ of the the Corti , which is a sensory organ that responds to vibration by initiating nerve impulses that are then percieved as hearing within the brain
        
        Auditory receptors
        
        vestibulocochlear nerve(8th cranial nerve)- passes through the foramen in the temporal bone to reach the hearing area in the temporal lobe.
        
        Scala typanic
        
        ends at the round window, some of the waves are also transmitted here.
        
        semi circular canals
        
        important for balance