Physio - Sense of Hearing Flashcards
Which part of the ear has both functions of hearing & equilibrium?
Inner ear
What forms the boundary between the External ear and the middle ear?
Tympanic membrane
Fill in the blanks. “ The oval Oval window and oval membrane receive and amplify vibrations from the ___________.”
Ossicles
Which ear ossicle vibrates against the oval window?
Stapes
Which ear ossicle is attached to the Eardrum?
Malleus
Which twi striated muscle attaches to the Malleus and the Stapes?
Stapedius and tensor tympani
What is the name of the structure that links the Middle ear and the Pharynx?
Pharyngotympanic tube ( Eustachian tube)
What are the functions of Ossicular conduction?
- Impedance matching (Amplification of sound): lever system & change in diameter.
- Attenuation/Tympanic reflex.
- To generate pressure waves in fluid present in cochlea.
Where does the middle & inner ear lie?
The middle and inner ear Lies within the petrous portion of the temporal bone.
Fill in the blanks. “ The bony labyrinth is filled with ____________ and is continuous with ____________.”
Bony labyrinth – filled with PERILYMPH and continuous with cerebrospinal fluid
’ BP”
What are the Parts of the Bony Labyrinth ?
Semicircular canals
Vestibule
Cochlea
What are the parts of the Membranous labyrinth?
Semicircular ducts
Utricle and saccule
Cochlear duct
Fill in the blanks. “The membranous labrynth is filled with __________.”
Endolymph
” ME”
True or False? The semicircular ducts are associated with the Membranous labyrinth while the semicircular canal is associated with the Bony larbyrinth.
FALSE!!
Semicircular DUCTS = Membranous labyrinth
Semicircular Canal = Bony labyrinth
‘ after B comes C - b for bony c- for canal’
What is the name given to the child around a pillar of bone?
Modiolus
What is the Spiral lamina?
A spiral of bone in the modiolus.
True or False? The cochlear artery runs through the core of the modiolus.
FALSE !! The cochlear nerve runs through the core of the Modiolus
Where is the Organ of Corti located?
Cochlear duct (scala media)
Where does the Cochlear duct lie between ?
The scala vestibuli - vestibular membrane
The scala tympani - basilar membrane
What structure secretes Endolymph (high in potassium and low in sodium)?
Stria vascularis
True or False? The Basiallar membrane is gelatinous and DOES NOT vibrate with sound.
FALSE!! TECTORIAL membrane is gelatinous and does not vibrate with sound.
Fill in the blanks. “ In the Organ of Corti , hair cells are surrounded by __________.”
Supporting cells
Fill in the blanks. “__________ is embedded in modiolus and innervates hair cells.”
Spiral Ganglion
True or False? The Basilar membrane vibrates in response to sound.
TRUE!!
Fill in the blanks. “ ________________ displaces stereocilia AWAY from modiolus – potassium channels open – potassium enters from endolymph and hair cell depolarises.”
UPWARDS movements
away—–> K+ channel open —-> depolarise
Fill in the blanks. “ ______________ displaces stereocilia towards modiolus – potassium channels close and hair cells hyperpolarise.”
DOWNWARDS movement
- towards —–> K+ close —> hyperpolarise
Fill in the blanks. “ ____________ moves Tectorial membrane .”
Fluid Waves
What are the two components of sound?
Frequency and amplitude
True or False? The distance of the peak from the base of basilar membrane is directly proportional to frequency .
FALSE !! The distance of the peak from the base of basilar membrane is INVERSELY proportional to frequency
Fill in the blanks. “ The basilar membrane is THICKER and STIFFER at the _____________ and THINNER at the ________.”
THICKER at the BASE
THINNER at the APEX
’ base is thiccc’
Fill in the blanks. “ Signals go through the cochlear nerve and vestibulocochlear nerve (CN VIII) to the ___________.”
Cochlear nucleus in the medulla
What are the two structures that make yo the Vestibular Apparatus?
Semicircular canals
Otolith organs
True or False? The semicircular canals are associated with a rotational acceleration while the Otolith organs are associated with a linear acceleration.
TRUE !!
What is the function of the Utricle & Saccule ?
They provide information on the position of the head relative to gravity (Linear acceleration).
What is the central part of the Bony labyrinth called?
The Vestibule
Fill in the blanks .” The utricle and Saccule are suspended in ________.”
Perilymph
What is the function of the Macula?
They monitor the position of the head when the head is still.
What type of cells are found in the Macula?
Supporting cells & Receptor (hair ) cells synapsed with the vestibular nerve .
What is the name of the structure that is housed in the Ampulla of the semicircular ductl?
Crista ampullaris
Fill in the blanks. “ The stereocilia of the hair cells are embedded in a gelatinous projection called ________.”
The copula
True or False? Kinocilia and stereocilia are all orientated in the SAME direction on each side of the head.
TRUE !!
What are Angular movements?
Yes and No movements
Fill in the blanks. “ Hair cells have small cilia called__________, plus one large cilium, _________.”
Small cilia called STEROCILIA
One large cilium called the KINOCILIUM
True or False? Processes of the hair cells project into the Perilymph.
FALSE!! Processes of Hair cells project into the ENDOLYMPH
Low sodium bases of hair cells are bathed in ?
Perilymph
True or False? Bases of hair cells are in contact with the efferent fibres of the vestibular division of the cochlear nerve .
FALSE!! Bases of hair cells are in contact with the AFFERENT fibres of the vestibular division of the VESTIBULOCOCHLEAR nerve
Fill in the blanks. ‘ The bending( displacing of cilia TOWARDS the Kinocilium causes _________ while bending ( displacing) of cilia AWAY from Kinocilium causes __________.”
TOWARDS the Kinocilium - Excitation & Depolarisation
AWAY from Kinoclium - Inhibition & Hyperpolarisation
What are the 4 main targets of the Vestibular nuclei ?
- Spinal cord (vestibulospinal tract)
- Nuclei of the extraocular muscles through the medial longitundinal fasciculus using CNIII, IV, and VI .
- Cerebellum
- Thalamus: which projects to the cortex.
Fill in the blanks. “ __________________ influence motor neurons to neck and back muscles.”
Medial vestibulospinal tract
Fill in the blanks. “ __________________ influence motor neurons to limb (especially extensor antigravity) muscles.”
Lateral vestibulospinal tract
Fill in the blanks. “ Axons in the MLF excite the ___________ and the _________.”
Axons ascend in the MLF and excite the ipsilateral oculomotor (III) nucleus and the contralateral abducens (VI) nucleus
True or False? Superior and medial vestibular neurons project to motor nuclei supplying extraocular muscles.
TRUE!!
What is Conduction deafness ?
This occurs when something hampers sound conduction to the fluids of the inner ear (e.g., impacted earwax, perforated eardrum, osteosclerosis of the ossicles).
Which pathology results from damage to the neural structures at any point from the cochlear hair cells to the auditory cortical cells?
Sensorineural deafness
Fill in the blanks. “ ________________ is the ringing or clicking sound in the ears in the absence of auditory stimuli.”
Tinnitus
What happens in Meniere’s syndrome ?
This is a labyrinth disorder that affects the cochlea and the semicircular canals, causing vertigo, nausea, and vomiting
