Physiology of Hearing and Balance Flashcards
what is the tympanic membrane to oval window ratio?
18:1
what is the resting state of the eustachian tube closed by?
by tensor veli palatini and levator palatine musles
what does dysfunction in the eustachian tube lead to?
middle ear negative pressure, can lead to fluid in the ear
what are the 2 openings of the cochlear to the middle ear?
oval window and round window
what is suspended between the scala tympani and the scala vestibuli (perilymph)?
scala media (endolymph)
what is inside the scala media (endolymph)?
organ of corgi
what does the organ of corgi contain?
hair cells
what do the hair cells in the organ of corgi sit on?
the basilar membrane
how are the hair cells in the basilar membrane arranged?
arranged in height order with tip links connecting them
in which direction must the hair cells be moving if depolarisation is occuring?
deflecting towards the longest side of the arrangement of hair cells
if there is hyperpolarisation of the hair cells, what way will they be moving?
deflecting away from the longest side
what does the pneumonic ‘E.coli’ stand for in terms of the primary auditory cortex?
E- eight cranial nerve C- cochlear nerve O- superior Olivary complex L- lateral lemniscus I- inferior colliculus
what are the 5 key vestibular end-organs?
- maculae of the utricle
- maculae of the saccule
- ampullae of lateral, posterior and superior semicircular canals
what are the utricle and saccule called collectively?
otolith organs
the maculae of the otolith organs have stereocilia that project towards into what?
project upwards into a gelantinous matrix with otoconia