STUDY GUIDE T - UNIT 4 Flashcards
(32 cards)
What are the parts of the external ear?
Auricle, external acoustic meatus, tympanic membrane
Function of auricle?
Funnels sound into ear
What does the external acoustic meatus do?
Carries sound to tympanic membrane
What do ceruminous glands produce?
Cerumen (earwax) → protects, traps debris
What is the tympanic membrane and its function?
Eardrum; vibrates to transmit sound to middle ear
What are the auditory ossicles (in order)?
Malleus → Incus → Stapes
What is the function of ossicles?
Amplify and transmit vibrations to oval window
What muscles protect from loud sound?
Tensor tympani & stapedius
What does the auditory tube connect?
Middle ear ↔ nasopharynx (equalizes pressure)
What fluid fills the bony labyrinth?
Perilymph (like CSF)
What fluid fills the membranous labyrinth?
Endolymph (high K⁺, like ICF)
What are the 3 regions of the bony labyrinth?
Cochlea (hearing), Vestibule, Semicircular canals (balance)
What is the cochlea’s function?
Converts sound waves into neural signals
What is the spiral organ and where is it located?
Hearing receptor, sits on basilar membrane
What do hair cells in the cochlea do?
Detect vibration → send signals via CN VIII
What is the tectorial membrane?
Covers hair cells, helps bend stereocilia
Sound pathway through ear?
Auricle → Meatus → Tympanic membrane → Ossicles → Oval window → Cochlea → Hair cells → CN VIII
Function of oval & round windows?
Oval: entrance of vibration; Round: pressure relief
How is pitch detected?
Location on basilar membrane
How is loudness detected?
Amplitude of basilar membrane movement
What nerve carries hearing info to brain?
Cochlear branch of CN VIII
Where is the primary auditory cortex?
Temporal lobe
What detects equilibrium?
Vestibular apparatus (utricle, saccule, semicircular canals)
What is static equilibrium?
Detects head position at rest
