Auditory System Quiz

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Questions and Answers

What is the factor that determines the volume of sound?

Wave speed

Wave frequency

Wave duration

Wave amplitude (correct)

How does a whisper differ from louder sounds in terms of sound wave characteristics?

It has a lower frequency and higher amplitude.

It has a lower amplitude and higher frequency.

It has a lower amplitude and lower frequency. (correct)

It has a higher frequency and lower amplitude.

Which structure of the external ear is primarily responsible for collecting sound waves?

External auditory canal

Auricle (Pinna) (correct)

Tympanic membrane

Temporal bone

What component of sound is frequency associated with?

Pitch Signup and view all the answers

What are the two branches of the vestibulocochlear nerve?

Cochlear and vestibular branches Signup and view all the answers

In which part of the ear does the external auditory canal lead into?

Middle ear Signup and view all the answers

Which structure is involved in dynamic balance?

Semicircular canals Signup and view all the answers

What does the oval window lead to in the inner ear?

Cochlea Signup and view all the answers

What happens to wave frequency when pitch is low?

It decreases and waves are spaced farther apart. Signup and view all the answers

What term is used to describe the structure where ear wax is typically found?

External auditory canal Signup and view all the answers

The round window functions primarily as what?

An exit point for fluid waves Signup and view all the answers

What is the main role of the auricle in the auditory system?

Gathering sound waves and directing them towards the middle ear Signup and view all the answers

Which of the following statements about the cochlea is incorrect?

It contains specialized cells for balance. Signup and view all the answers

Which of the following best describes the function of the vestibule?

Static balance Signup and view all the answers

What separates the internal structures of the inner ear?

Membranes Signup and view all the answers

What is the primary function of the cochlear branch of the vestibulocochlear nerve?

Transmitting sound signals Signup and view all the answers

What is the primary function of the kinocilium in the hair cells?

To enhance the sensitivity of stereocilia to movement Signup and view all the answers

How does the otolithic membrane contribute to the process of static equilibrium?

It moves with gravity, which then tilts hair bundles. Signup and view all the answers

What happens to the hair bundles when the head is tilted forward?

They are pulled and tilted, leading to depolarization. Signup and view all the answers

What ionic change occurs as a result of depolarization in hair cells?

Potassium ions rush into the cells. Signup and view all the answers

Which structure is primarily associated with detecting changes in head position relative to gravity?

Otoliths Signup and view all the answers

What role do tip links play in the function of hair cells?

They connect adjacent stereocilia and allow ion channels to open. Signup and view all the answers

What is the consequence of the otoliths moving in response to gravity?

They generate action potentials in the hair cells. Signup and view all the answers

Why is it important for hair cells to send information to the vestibular nerve?

To maintain balance and posture. Signup and view all the answers

What structure is primarily responsible for detecting the movement of the head in different directions?

Crista ampullaris Signup and view all the answers

In which part of the semicircular canals are the hair cells located?

In the ampulla Signup and view all the answers

What substance fills the semicircular canals, allowing them to detect movement?

Endolymph Signup and view all the answers

Which of the following is unique to the crista when compared to hair cell locations in other vestibular structures?

Embedded in the gelatinous cupula Signup and view all the answers

What is the primary function of the semicircular canals?

To detect dynamic equilibrium and movement Signup and view all the answers

Which region of the semicircular canal is enlarged and contains the crista?

Ampulla Signup and view all the answers

What determines the brain's interpretation of the direction of head movement?

Amount of fluid movement in each canal Signup and view all the answers

Which statement accurately describes the relationship between the semicircular canals and the planes of movement?

They detect movement across the x, y, and z planes. Signup and view all the answers

What role does the cupula play in detecting head movement?

It moves in response to fluid motion within the semicircular canals. Signup and view all the answers

How does head movement influence the fluid within the semicircular canals?

The fluid's direction opposes the head's movement initially. Signup and view all the answers

What happens to the hair cells when the cupula tilts?

The tip links open, allowing potassium influx. Signup and view all the answers

Why does the fluid in the semicircular canals initially move in the opposite direction of the head?

Due to inertia, the fluid takes time to adjust. Signup and view all the answers

What effect does moving at a constant speed have on the cupula?

The cupula returns to an upright position as fluid stabilizes. Signup and view all the answers

What is the significance of hair cell depolarization in the vestibular system?

It initiates synapse formation with vestibular nerves. Signup and view all the answers

What occurs when the car comes to a sudden stop?

The fluid continues to move in the original direction for a moment. Signup and view all the answers

What is the primary function of the vestibulocochlear nerve in relation to head movement?

It transmits balance information to the brain. Signup and view all the answers

What role do tip links play in the function of stereocilia?

They connect stereocilia, facilitating the opening of ion channels. Signup and view all the answers

Which ion is primarily responsible for depolarization in hair cells when stereocilia are displaced?

Potassium Signup and view all the answers

What occurs to the gating springs when the stereocilia bend towards taller stereocilia?

They stretch and open the ion channel. Signup and view all the answers

What is the configuration of microvilli in the resting condition?

Upright and connected. Signup and view all the answers

How does the movement of the basilar membrane affect the hair cells?

It moves the bottom of the hair cell, causing stereocilia to bend. Signup and view all the answers

What happens to the potassium ion concentration during depolarization of hair cells?

It becomes lower in the hair cell compared to the endolymph. Signup and view all the answers

What causes the gating springs to stretch and open the ion gated channel?

The deflection of stereocilia towards the tallest ones. Signup and view all the answers

What characterizes the depolarization mechanism in hair cells compared to typical neurons?

It is triggered by potassium ion influx. Signup and view all the answers

Study Notes

Special Senses: Hearing & Balance

Transcripts are from automatically generated lecture captions, not edited
Lecture 22, Video 1 covers Hearing and Balance
Anatomy of the external, middle, and inner ears are reviewed
Sound waves converted into electrical signals for the brain
Inner ear structures related to balance explain head position and acceleration/deceleration
Motion sickness discussed in relation to reading in cars

Slide 1 - Hearing Structures

Cochlea in the inner ear's temporal bone, emphasized in a unique picture
Temporal bone illustration removed to reveal inner ear structures
Cochlea discussed in more detail later

Slide 2 - Sound Terminology

Sound is air vibration creating compressed and less compressed air bands = sound waves
Wave amplitude determines sound volume
Wave frequency determines pitch

Slide 3 - Ear Structures

External ear: auricle (pinna) collects sound waves, directed to middle ear
External auditory canal: sound wave channel, starting as soft tissue with cartilage, then bone
Ear wax (cerumen): prevents foreign bodies and insects
Tympanic membrane (eardrum): where sound wave vibrations start; thin membrane
Middle ear: air-filled cavity with auditory ossicles
Auditory ossicles: three small bones (malleus, incus, stapes): amplify vibrations
Malleus: connected to tympanic membrane, acts like a hammer
Incus: anvil-shaped connecting malleus to stapes
Stapes: stirrup-shaped, final bone; connected to oval window

Slide 3 - Ear Structures Continued

Auditory tube (eustachian tube): equalizes air pressure between middle ear and outside environment
Equal air pressure on both sides of the eardrum necessary for proper functioning
Actions like chewing, swallowing, or yawning help equalize pressure

Slide 4 - Inner Ear Structures

Inner ear: external & middle ear connected to inner ear
Oval window: opening in inner ear; stapes vibrates this membrane
Round window: opening to release vibrations
Vestibule: static balance; relates to head position
Semicircular canals: dynamic balance; relates to head acceleration/deceleration
Vestibulocochlear nerve (Cranial nerve VIII): connects inner ear to brain

Video 2 - Inner Ear

Membranous labyrinth: series of membranes within the bony labyrinth
Specialized epithelial cells, fluids
Perilymph: fluid between bony and membranous labyrinth
Endolymph: fluid within the membranous labyrinth; high potassium, low sodium
Cochlear duct: central inner ear part, surrounded by perilymph chambers
Basilar membrane: separates cochlear duct and scala tympani/vestibuli
Tectorial membrane: covering hair cells on basilar membrane
Hair cells (stereocilia): specialized receptor cells in organ of Corti; convert sound vibrations to electrical signals
Cochlear nerve: transmits electrical signals to brain

Video 2 Continued

Outer hair cells: regulate basilar membrane tension, affect sensory input
Inner hair cells: detect sound waves, transmit signal to brain about auditory response
Pitch perception: high pitch sounds stimulate hair cells near oval window, low at helicotrema
Volume perception: loud sounds stimulate more hair cells

Slide 9 - Hair Cell Microvilli

Stereocilia (microvilli) of hair cells move relative to each other; physically open ion channel gates
Potassium inflow depolarizes hair cells; creates electrical signals
Ion channel opening due to basilar membrane movement

Slide 10 - Auditory Pathway Summary

Sound waves travel through external ear, middle ear bones to inner ear
Vibrations of inner ear cause electrical signals to be sent to the brain
Brain interprets signals as sound, pitch, and volume

Slide 11-12 - Hearing Pathway Summary

Detailed steps of hearing process, linking numbered steps to ear components

Slide 13 - Balance

Vestibule (utricle and saccule): static equilibrium (head position)
Hair cells in macula: sense head position relative to gravity
Otoliths: masses on otolithic membrane; sensory information to brain about head position
Semicircular canals: dynamic equilibrium (dynamic balance or acceleration/deceleration)
Crista ampullaris: specialized receptor cells detect head movement
Hair cells in crista: sense head movement

Slide 17 - Balance Mechanisms

Hair cells in crista, embedded in cupula; sense head movement
Fluid movement in semicircular canals causes cupula to shift
Hair cell movement opens/closes gates, sending info to brain about head movement

Slide 18 - Motion Sickness

Vestibular system's sensory info conflict with other systems (visual)
Motion sickness due to conflicting sensory information causes nausea

Conclusion

Lecture covered hearing (external, middle, inner ear structures), and balance (static and kinetic) mechanisms

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Description

Test your knowledge of the auditory system with this quiz. It covers sound volume, ear structures, and the functions of various components related to hearing and balance. Perfect for students learning about human anatomy and physiology.