Lecture 5: Ear Flashcards
What is the function of the outer ear?
Receives sound waves
What is the function of the middle ear?
Transmits sound waves from tympanic membrane to inner ear
The inner ear contains _______ organs.
sensorineural
What are the structures that make up the outer ear? (3)
- Auricle or pinna
- External auditory meatus
- Tympanic membrane = eardrum
What structures make up the middle ear? (4)
- Tympanic cavity
- Auditory or Eustachian tube
- Auditory ossicles = malleus, incus, stapes
- Oval and round windows
What structures make up the bony labyrinth of the inner ear? (3)
- Vestibule
- Semicircular canals (3)
- Cochlea
What structures make up the membranous labyrinth of the inner ear? (4)
- Utricle
- Saccule
- Semicircular ducts
- Cochlear ducts
The auricle is covered by skin that contains _____ cartilage.
elastic
The external auditory meatus contains what type of glands?
ceruminous glands
What type of epithelium lines the tympanic cavity?
(endoderm-derived) simple squamous epithelium
Which structures does the auditory/eustachian tube connect?
connects tympanic cavity to nasopharynx
What type of epithelium lines the auditory/eustachian tube?
ciliated pseudostratified columnar epithelium
What two small thin membranes separate the middle and inner ear?
oval and round windows
The middle ear contains what two small muscles?
stapedius and tensor
What structure do the stapes push?
oval window
What structure pushes the malleus?
tympanic membrane
Which structure of the inner ear contains perilymph fluid?
bony labyrinth
Which structure of the inner ear contains endolymph fluid?
membranous labyrinth
What are stereocilia called on the receptors of the inner ear?
hair cells
All 3 receptors of the inner ear have a ______ ______ system.
sensorineural transduction
What occurs when stereocilia hyperpolarize?
release more neurotransmitter
What occurs when stereocilia depolarize?
release less neurotransmitter
The Organ of Corti has what type of membrane?
basilar
What is scala media? What is its function?
- cochlear duct that contains the cochlea
- Converts vibrations in the perilymph (in scala vestibuli) to the cochlear duct’s endolypmh = sets a vibration in the basilar membrane = results in movement in hair cells and then nerve impulses
What is the result of displacement of stereocilia?
results in action potential to the cochlear duct
What is the result of high frequency sounds?
displacement near the base of the basilar membrane
What is the result of low frequency sounds?
displacement at the apex of the basilar membrane
What does the internal ear fluid movement from vibration of the oval window cause?
vibrational wave in the basilar membrane leading to stimulation of the hair cells = nerve impulse
What is the function of the crista ampullaris?
sensor of angular motion/rotation
Where is maculae located?
in saccule and utricle
What is the function of the maculae?
gravity and linear acceleration
The octoconia and thus otolithic membrane are displaced during _______.
acceleration
Movement ____ the kinocilum opens channels. Movement ____ closes channels.
toward, away
What structure does the membranous labyrinth develop from?
otic vesicle
What structure does the outer ear develop from?
first pharyngeal groove
What structure does the middle ear develop from?
first pharyngeal pouch
What structure do the malleus and incus develop from?
cartilage of first pharyngeal arch
What structure do the stapes develop from?
second arch cartilage
What is #1?
Macula
What is #2?
Utricle with endolymph
What is #3?
Otoconia
What is #4?
Otolithic membrane
What is #5?
Hair cells
What is #1?
Scala vestibuli
What is #2?
Vestibular membrane
What is #3?
Tectorial membrane
What is #4?
Inner tunnel
What is #5?
Cochlear duct
What is #6?
Outer tunnel
What is #7?
Stria vascularis (decoy)
What is #8?
Spiral ligament
What is #9?
Inner spiral tunnel
What is #10?
Inner hair cell
What is #11?
Outer hair cell
What is #12?
Outer phalangeal
What is #13?
Basilar membrane
What is #14
Scala tympani
What is #1?
Utricle with endolymph
What is #2?
Crista ampularis
What is #1?
Ampula of semicircular canal with endolymph
What is #2?
Cupula
What is #3?
Hair cells
What is #4?
Crista ampullaris
What is #1?
Outer tunnel
What is #2?
Inner tunnel
What is #3?
Tectorial membrane
What is #4?
Basilar membrane
What is #5?
Outer phalangeal
What is #6?
Outer hair
What is #7?
Inner hair cell
What is #8?
Inner spiral tunnel
What is #1?
Ampula of semicircular canal with crista ampullaris
What is #2?
Utricle with macula
What is #1?
Cochlear duct
What is #2?
Organ of Corti
What is #3?
Scala tympani
What is #4?
Scala vestibuli
What is #5?
Spiral ganglia
- Which of the following inner ear structures contain the macula?
a. Cochlear duct
b. Semicircular ducts
c. Saccule of the vestibule
d. Scala media
c. Saccule of the vestibule
- Identify the following structure:
a. Organ of corti
b. Basilar membrane
c. Tectorial membrane
d. Reissner’s membrane
c. Tectorial membrane
- The cochlea is divided into 3 chambers, which chamber contains the organ of corti?
a. Scala media
b. Scala vestibuli
c. Scala tympani
d. Vestibular duct
a. Scala media
- The sensory hair cells of the crista ampullaris are responsible for:
a. Linear acceleration
b. Low pitch frequencies
c. Angular acceleration
d. High pitch frequencies
c. Angular acceleration
- Where is the cochlear duct located and which type of fluid does it contain?
a. Cochlea; perilymph
b. Scala tympani; endolymph
c. Cochlea; endolymph
d. Scala media; perilymph
c. Cochlea; endolymph