Lecture 1 Flashcards
What comprises the external ear?
Auricle, ear canal, tympanic membrane
Example sentence: The external ear is made up of the auricle, ear canal, and tympanic membrane.
What comprises the middle ear?
Eustacain tibe
Example sentence: The middle ear consists of the eustacian tube.
What comprises the inner ear?
Cochlea, semicircular canals, oval window
Example sentence: The inner ear includes the cochlea, semicircular canals, and oval window.
What is the structure that has a shape to capture and concentrate soundwaves?
Auricle
Example sentence: The auricle is the structure that captures and concentrates soundwaves.
What does the auricle good for?
Sound localization
Example sentence: The auricle is important for sound localization.
The ear canal is shaped like an
S
Example sentence: The ear canal is shaped like an ‘S’.
What is the external ear structure that is comprised of a thin, elastic membrane that separates the ear canal from the inner ear?
Tympanic membrane
Example sentence: The tympanic membrane is a thin, elastic membrane separating the ear canal from the inner ear.
The tympanic membrane will function how?
Sound waves strike the TM and cause it to vibrate and the virbation are transferred to the ossicles
Example sentence: The tympanic membrane vibrates when sound waves strike it and transfers the vibrations to the ossicles.
What are the sections of the external ear and their structures?
Ear canal - outer portion with hair to filter substances and glands that secrete cerumen
Tympanic membrane- thin, elastic membrane
Example sentence: The external ear consists of the ear canal with hair for filtering substances and glands that secrete cerumen, as well as the thin, elastic tympanic membrane.
The middle ear canal is good for what conducton
Bony and air
Example sentence: The middle ear canal is important for conducting both bony and air vibrations.
The middle ear canal will transmit energy of
Soundwaves from the air to the fluids in the inner ear that was amplified by the ossicles
Example sentence: The middle ear canal transmits energy from soundwaves in the air to the fluids in the inner ear, which are amplified by the ossicles.
The eustacian tube is the opening in the
Middle ear
Example sentence: The eustacian tube is the opening in the middle ear.
What lines the ustacian tibe
Mucosal lining that extends from the middle ear to the nasopharynx
Example sentence: The eustacian tube is lined with mucosa that extends from the middle ear to the nasopharynx.
What does eustacian tube do with the TM
Equalize pressure of the TM so the TM can transmit waves to the ossicles
Example sentence: The eustacian tube equalizes pressure of the tympanic membrane so it can transmit waves to the ossicles.
The inner ear cochlea houses what 3 parallel tubes
Scala vestibuli, scala tympani, scala media
Example sentence: The cochlea in the inner ear contains three parallel tubes: scala vestibuli, scala tympani, and scala media.
What is the process of sound transduction in the middle ear?
The perilymph in the scala vestibuli and tympani move with Transmitted waves
The movement of the scala vestibuli and tympani will eventially disspate by Movement of the round window
Displacement of the endolymph with sound transmission to vestibular membrane
Perilymph and endolymph will transmit the mechanical vibrations from the footplate to the stapes od the organ of croti
The hair cells on the organ of corti that are in contact with the tectorial membrane will move
Action transforms the mechanical energy of the sound waves to electrical impulses stimulating vestibular nerve
Example sentence: The process of sound transduction in the middle ear involves the movement of perilymph, displacement of endolymph, and transformation of mechanical energy to electrical impulses.
The impulses when the get to the vestibular nerve will reach the
Nuclei in the medulla, pons, midbrain, thalamus and then the auditory area of the temporal lobe
Example sentence: The impulses reaching the vestibular nerve travel to nuclei in the medulla, pons, midbrain, thalamus, and finally the auditory area of the temporal lobe.
Normally there is no ___________ between the endolymph and _______
Communication; perilymph
Example sentence: Normally, there is no communication between the endolymph and perilymph.
Movement of the head will cause what in the endolymph
Movement of the endolymph
Example sentence: Head movement causes movement of the endolymph.
What will happen with movement of the endoplymph
Receptor hair cells creat nerve impulse in vestibular portion of the CN VIII where stimuluar is Transmitted to the brain
Example sentence: Movement of the endolymph stimulates receptor hair cells, creating nerve impulses that are transmitted to the brain.
What is the difference between vertigo and dizziness?
Vertigo is the sensation of motion without actual motion.; NO association with syncompe or impending syncope
Dizziness: feeling of being off balanced, faint or woozy
Example sentence: Vertigo is the sensation of motion without actual motion, while dizziness refers to feeling off-balance, faint, or woozy.
What is often noted with Vertigo?
Nystagmus
Example sentence: Nystagmus is often noted in cases of vertigo.
What things can cause vertigo
Mineires Disease
Disorders of the brains stem or cerebellum
Certain drugs - anticonvulsants and sedatives
Alcohol
Example sentence: Vertigo can be caused by Meniere’s disease, disorders of the brain stem or cerebellum, certain drugs like anticonvulsants and sedatives, and alcohol.
What things cause hearing loss stemming from the outer ear
Impacted cerumen or foreign body
Example sentence: Hearing loss stemming from the outer ear can be caused by impacted cerumen or foreign bodies.
What things cause hearing loss stemming from the Middle ear
Fluid effusion
Infection (otitis media)
Tumors
Otosclerosis
Example sentence: Hearing loss stemming from the middle ear can be caused by fluid effusion, infection like otitis media, tumors, and otosclerosis.
What things cause hearing loss stemming from noise c
Loud nosies
Example sentence: Hearing loss stemming from noise exposure can be caused by loud noises.
What medications can cause hearing loss
Ototoxic meds like aminoglycosides, chemo agents, high dose loop diuretics
Example sentence: Hearing loss can be caused by ototoxic medications such as aminoglycosides, chemotherapy agents, and high-dose loop diuretics.
What are common infectiosn (especially in children) cause hearing loss
Meningitis and measles
Example sentence: Common infections like meningitis and measles, especially in children, can cause hearing loss.
_________ teratogens like radiation can cuase hearing loss
Environmental
Example sentence: Environmental teratogens like radiation can cause hearing loss.
What intrauterine infections would cause hearing loss
Cytomegalovirus
Herpes simplex virus
HIV
Toxoplasma
Example sentence: Intrauterine infections such as cytomegalovirus, herpes simplex virus, HIV, and toxoplasma can cause hearing loss.
Expsure to what chemicals can lead to hearing loss
Solvents and pesticides
Example sentence: Exposure to chemicals like solvents and pesticides can lead to hearing loss.
What are common infections that can cause hearing loss, especially in children?
Meningitis and measles
Example sentence: Children with measles may develop hearing loss.
What are teratogens that can cause hearing loss?
Environmental
Teratogens like radiation can cause hearing loss.
What intrauterine infections can cause hearing loss?
Cytomegalovirus, Herpes simplex virus, HIV, Toxoplasma
What chemicals can lead to hearing loss?
Solvents and pesticides
What are maternal metabolic disorders that can lead to hearing loss?
Diabetes and hypothyroidism
Maternal metabolic disorders leading to hearing loss.
What are the types of hearing loss and their differences?
Conductive - sound can’t reach cochlea
Sensorineural - inner ear hearing mechanism is disrupted
Central deafness - destruction of cochlear nuclei in auditory pathways
What are the 4 mechanisms of conductive hearing loss?
Obstruction - cerumen impaction
Mass loading - middle ear effusion
Stiffness effect - otosclerosis
Discontinuity - ossicular disruption
What is the progressive hearing loss caused by stapedial fixation?
Otosclerosis
Example sentence: Otosclerosis can be accelerated by pregnancy.
What is the most common group affected by otosclerosis?
Middle-aged Caucasian women
What is sensorineural hearing loss?
Loss of hearing not directly related to dysfunction of CN VIII
What is the most common cause of sensorineural hearing loss?
Long-term exposure to loud sounds, trauma, medications, aging
What do ototoxic medications impact the most?
The hair cells in the cochlea
When does hearing loss from ototoxic medications typically take effect?
Days to weeks post medication completion
Which medications are known to be ototoxic?
Aminoglycoside antibiotics, Salicylates (aspirin), Quinine and other antimalarials, Cytotoxic antineoplastic drugs (chemotherapy)
What is the most common cause of noise-induced sensorineural hearing loss in the US?
Trauma from noises on the job, firearms, music, power tools, certain occupations
What is the threshold for noise-induced sensorineural hearing loss?
85 dB
What are the 2 phases of noise-induced hearing loss?
Temporary threshold shift, Permanent threshold shift
What signs indicate head trauma to the ear?
Bleeding and temporal bone fracture
What is presbycusis?
Loss of hearing resulting from disorders in the inner ear not directly related to CN VIII dysfunction
What is the excessive accumulation of endolymph in the membranous labyrinth?
Meniere disease
Example sentence: Meniere disease can cause vertigo and hearing loss.
What is the inflammatory condition of the middle ear that results from Eustachian tube dysfunction? It can be chronic/acute?
Otitis media; both
Commonly found with OM: Effusion
What is the condition caused by purulent discharge collecting in the mastoid air cells?
Mastoiditis
Mastoiditis can lead to deep neck abscesses if the infection tracks under the periosteum of the temporal bone eroding through the mastoid tip.
What can increased pressure in the mastoid air cells lead to?
Erosion of surrounding bone and the formation of abscess-like cavities
Example sentence: The increased pressure in the mastoid air cells can lead to the erosion of surrounding bone.
What can mastoiditis lead to if the infection tracks under the periosteum of the temporal bone?
Deep neck abscesses
Example sentence: Mastoiditis can lead to deep neck abscesses if the infection tracks under the periosteum of the temporal bone eroding through the mastoid tip.
