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