Hearing and Balance

What are the components of the outer ear

• Auricle/pinna

• External Acoustic Meatus/ear canal

• tympanic membrane (ear drum)

what are the components of the middle ear?

• ossicles (malleus, Incus, Stapes)

• Oval window

• round window

• eustchain tube

what is the inner ear composed of

cochlea

In what order does sound travel through the ear structures?

1. Auricle

2. Ear canal

3. tympanic membrane (ear drum)

4. ossicles to oval wall

5. cochlea

6. cochlear nerve

A six-year-old patient comes into the ER expressing ear pain. Upon closer inspection with an otoscope, you see a Lego traffic cone stuck inside their ear. What specific structure is the traffic cone stuck in, and in what general ear region is this structure located?

A. Auricle, Outer ear

B. Auricle, Middle ear

C.External acoustic meatus, Outer ear

D. External acoustic meatus, Middle ear

C.External acoustic meatus, Outer ear

At which structure will the sound energy change into electrical energy

pinna - sound energy

tympanic membrane - mechanical energy

hair cells - electrochemical energy

What is the primary role of mechanical transduction in the process of hearing?

A) Amplifying sound waves in the external ear.
B) Converting sound waves into electrical signals for the brain to interpret.
C) Transmitting sound waves directly to the auditory cortex.
D) Equalizing air pressure in the middle ear.

B) Converting sound waves into electrical signals for the brain to interpret.

What is the primary function of the cochela?

A) To equalize pressure between the middle ear and the atmosphere.

B) To amplify sound vibrations using ossicles.

C) To turn sound waves into neural signals.

D) To regulate balance and spatial orientation.

C) To turn sound waves into neural signals.

Which of the following are the fluid-filled compartments of the cochlea?

A) Tympanic cavity, Eustachian tube, and Oval window.

B) Scala vestibuli, Scala media, and Scala tympani.

C) Cochlear duct, Semicircular canals, and Vestibule.

D) Endolymph, Perilymph, and Round window

B) Scala vestibuli, Scala media, and Scala tympani.

Why is the maintenance of an appropriate ionic environment critical in the cochlea?

A) It supports the amplification of sound waves.

B) It facilitates the mechanical movement of ossicles.

C) It enables hair cell function for signal transmission.

D) It equalizes the pressure in the inner ear.

C) It enables hair cell function for signal transmission.

What is the spiral shaped structure in the inner ear

cochlea

Which structure supports the Organ of Corti (Spiral Organ)?

A) Tectorial membrane and Basilar membrane

B) Scala vestibuli

C) Vestibular membrane

A) Tectorial membrane and Basilar membrane

What is the function of the tectorial membrane in the cochlea?

A) To protect the hair cells from damage.

B) To interact with hair cell stereocilia to facilitate sound transduction.

C) To transmit vibrations from the middle ear to the inner ear.

D) To separate the cochlear duct from the scala tympani.

B) To interact with hair cell stereocilia to facilitate sound transduction.

Approximately how many fibers are present in the cochlea to detect different sound frequencies?

A) 10,000

B) 15,000

C) 20,000

D) 30,000

C) 20,000

what properties change along the length of the cochlea allowing for frequency analysis

width and stiffness

What is the primary role of inner hair cells in the cochlea?
A) Amplifying sound vibrations.
B) Enhancing frequency selectivity.
C) Initiating the neural response to sound.
D) Regulating the movement of the basilar membrane.

C) Initiating the neural response to sound.

Which of the following describes the function of outer hair cells in the cochlea?
A) Detecting and transmitting sound signals to the auditory nerve.
B) Amplifying sound vibrations and enhancing frequency selectivity.
C) Separating the scala vestibuli from the scala tympani.
D) Transmitting electrical signals to the Organ of Corti.

B) Amplifying sound vibrations and enhancing frequency selectivity.

Where are the inner and outer hair cells located?
A) Basilar membrane
B) Tectorial membrane
C) Organ of Corti
D) Scala tympani

C) Organ of Corti

Organ of corti has two types of hair cells

• inner hair cells

• outer hair cells

What is the significance of each hair cell being connected to a neuron in the cochlea?

A) It allows hair cells to amplify sound vibrations more effectively.
B) It ensures direct transmission of auditory signals to the auditory cortex of the brain.
C) It enables hair cells to detect low-frequency sounds exclusively.
D) It facilitates the equalization of pressure in the middle ear.

B) It ensures direct transmission of auditory signals to the auditory cortex of the brain.

What does the frequency of a sound wave determine?
A) Loudness of the sound.
B) Pitch of the sound.
C) Duration of the sound.
D) Direction of the sound source.

B) Pitch of the sound.

Which property of a sound wave corresponds to its intensity?
A) Wavelength.
B) Frequency.
C) Amplitude.
D) Duration.

C) Amplitude

What aspect of sound does amplitude affect?
A) Pitch.
B) Loudness.
C) Frequency.
D) Direction.

B) Loudness

What is the primary function of the basilar membrane in the cochlea?

A. Transducing sound waves into electrical signals

B.Amplifying high-frequency sounds

C. Separating the cochlea into different fluid compartments

D. Detecting head and body movements

A. Transducing sound waves into electrical signals

What triggers hair cell depolarization in the auditory system?
A) Movement of the tectorial membrane.
B) Displacement of the basilar membrane.
C) Compression of the scala tympani.
D) Vibration of the tympanic membrane.

B) Displacement of the basilar membrane.

What happens when hair cells in the organ of Corti are moved?
A) Voltage-gated potassium channels open, causing hyperpolarization.
B) Mechanically-gated sodium channels open, initiating a graded action potential.
C) Mechanically-gated potassium channels open, initiating a graded action potential.
D) Sodium and potassium channels close, silencing the signal transmission.

B) Mechanically-gated sodium channels open, initiating a graded action potential.

How are action potentials transmitted after hair cell depolarization?
A) Directly through the cochlear fluid.
B) Along the auditory nerve to the auditory cortex.
C) Via the tectorial membrane to the vestibular nerve.
D) Through the oval window to the basilar membrane.

B) Along the auditory nerve to the auditory cortex.

What is the role of graded action potentials in the hair cells?
A) To generate mechanical vibrations in the basilar membrane.
B) To amplify the intensity of incoming sound waves.
C) To initiate action potentials transmitted along the auditory nerve.
D) To regulate endolymph production in the cochlear duct.

C) To initiate action potentials transmitted along the auditory nerve.

Which process forms the basis for auditory perception in the brain?
A) Vibration of the tympanic membrane.
B) Depolarization of hair cells and generation of action potentials.
C) Movement of perilymph in the scala tympani.
D) Compression of the stapes against the oval window.

B) Depolarization of hair cells and generation of action potentials.

If you were to damage the hair cells in the cochlea close to the round window, how would this impact your hearing?

You would no longer be able to hear high pitched sounds

What is the role of the auditory nerve in the auditory pathway?
A) To amplify sound vibrations.
B) To transmit information from the cochlea to the brainstem.
C) To detect differences in sound frequency.
D) To adjust the position of the basilar membrane.

B) To transmit information from the cochlea to the brainstem.

Where is sound perceived and analyzed in the brain?
A) Brainstem.
B) Midbrain.
C) Primary auditory cortex.
D) Cerebellum.

C) Primary auditory cortex.

What is the sequence of auditory information transmission from the cochlea to the brain?
A) Cochlea → Auditory Nerve → Brainstem → Midbrain → Primary Auditory Cortex.
B) Cochlea → Brainstem → Midbrain → Auditory Nerve → Primary Auditory Cortex.
C) Cochlea → Auditory Nerve → Midbrain → Brainstem → Primary Auditory Cortex.
D) Cochlea → Primary Auditory Cortex → Midbrain → Brainstem → Auditory Nerve.

A) Cochlea → Auditory Nerve → Brainstem → Midbrain → Primary Auditory Cortex.

Which structure is responsible for initially transmitting auditory signals to the brainstem?
A) Cochlear duct.
B) Tectorial membrane.
C) Auditory nerve.
D) Scala tympani.

C) Auditory nerve.

What is the primary characteristic of conductive hearing loss?
A) Damage to the auditory nerve.
B) Impairment of sound transmission through the external or middle ear.
C) Loss of hair cells in the cochlea.
D) Difficulty processing sound in the primary auditory cortex.

B) Impairment of sound transmission through the external or middle ear.

ex. otitis media, ruptured ear drum, otosclerosis

What is the primary characteristic of sensorineural hearing loss?
A) Impairment of sound transmission through the external or middle ear.
B) Difficulty transducing sound in the inner ear or processing auditory information in the brain.
C) Blockage of the auditory canal due to physical obstructions.
D) Disruption of pressure equalization in the middle ear.

B) Difficulty transducing sound in the inner ear or processing auditory information in the brain.

Which structure is primarily affected in sensorineural hearing loss?
A) Tympanic membrane.
B) Ossicles of the middle ear.
C) Hair cells in the cochlea or auditory nerve.
D) Eustachian tube.

C) Hair cells in the cochlea or auditory nerve.

what are the causes of sensorineural hearing loss

• aging

• noise damage

• drug side effects

• auditory tumors

• blast/explosions

what causes conductive hearing loss

• fluid

• foreign obects

• allergies

• ruptured ear drum

• impacted earwax

what can cause both conductive and sensorineural hearing loss

• genetic disorders

• infections

• head trauma

6 year old patient. They say that they can’t hear anything in that ear ever since putting the traffic cone in the ear. What type of hearing loss is this?

A. Conductive hearing loss

B. Sensorineural hearing loss

C. Mixed hearing loss

A. Conductive hearing loss

What is the primary function of the semicircular canals in the vestibular system?
A) Detecting linear acceleration.
B) Detecting angular acceleration and rotational movements.
C) Sensing changes in head position relative to gravity.
D) Amplifying sound waves for hearing.

B) Detecting angular acceleration and rotational movements.

How many semicircular canals are present in the vestibular system?
A) Two.
B) Three.
C) Four.
D) Five.

B) Three.

Which semicircular canals are responsible for detecting rotational movements?
A) Anterior, posterior, and lateral canals.
B) Otolith organs and cochlear duct.
C) Vestibular nerve and semicircular ducts.
D) Tympanic and vestibular membranes.

A) Anterior, posterior, and lateral canals.

How are the semicircular canals oriented to detect rotational movements in all directions?
A) They are parallel to each other.
B) They are perpendicular to each other in three different planes.
C) They are aligned with the cochlear duct.
D) They are connected in a circular loop.

B) They are perpendicular to each other in three different planes.

What is the primary function of the utricle and saccule (otolith organs) in the vestibular system?
A) Detecting angular acceleration.
B) Detecting sound waves.
C) contain hair cells that detect linear acceleration and head position
D) Amplifying sound vibrations for the cochlea.

C) contain hair cells that detect linear acceleration and head position

Where are vestibular hair cells located?
A) Only in the semicircular canals.
B) Only in the cochlea.
C) Throughout the semicircular canals and otolith organs.
D) In the tympanic membrane and oval window.

C) Throughout the semicircular canals and otolith organs.

What does the bending of vestibular hair cells indicate?
A) Changes in sound frequency.
B) The direction of movement
C) The intensity of sound waves.
D) The equalization of ear pressure.

B) The direction of movement

What is the primary role of vestibular hair cells in the vestibular system?
A) Amplifying sound waves in the inner ear.
B) Transducing head and body movements into neural signals.
C) Detecting pressure changes in the middle ear.
D) Maintaining equalization of ear pressure.

B) Transducing head and body movements into neural signals.

What happens when the stereocilia on vestibular hair cells are deflected?
A) The hair cells become hyperpolarized, reducing signal transmission.
B) The hair cells depolarize, initiating neural impulses.
C) The hair cells release neurotransmitters without depolarization.
D) The hair cells amplify movement of the endolymph.

B) The hair cells depolarize, initiating neural impulses.

Where are the neural signals from vestibular hair cells processed?
A) The cochlear nucleus.
B) The semicircular canals.
C) The central vestibular system.
D) The otolithic membrane.

C) The central vestibular system.

Which structures of the inner ear are directly involved in detecting angular acceleration?

A. Cochlea

B. Semicircular canals

C. Utricle

D. Saccule

E. Vestibular nerve

B. Semicircular canals

What is the primary function of the vestibulo-ocular reflex (VOR)?
A) To amplify sound vibrations in the inner ear.
B) To stabilize visual images on the retina during head movements.
C) To regulate pressure within the middle ear.
D) To detect angular acceleration and rotational movements.

B) To stabilize visual images on the retina during head movements.

Which two systems are connected in the neural pathway of the vestibulo-ocular reflex?
A) Auditory and vestibular systems.
B) Vestibular and oculomotor systems.
C) Oculomotor and somatosensory systems.
D) Vestibular and auditory cortex.

B) Vestibular and oculomotor systems.

How does the VOR maintain clear vision during head rotations?
A) By adjusting the focus of the lens in response to movement.
B) By triggering precise eye movements that counteract head motion.
C) By amplifying signals in the semicircular canals.
D) By equalizing pressure between the inner and middle e

B) By triggering precise eye movements that counteract head motion.

What is the primary function of the vestibulo-spinal reflexes?
A) To stabilize visual images on the retina during head movements.
B) To coordinate muscle contractions for maintaining balance and postural stability.
C) To amplify sound vibrations in the cochlea.
D) To regulate head position relative to gravity.

B) To coordinate muscle contractions for maintaining balance and postural stability.

Which two systems are primarily involved in vestibulo-spinal reflexes?
A) Vestibular system and auditory cortex.
B) Vestibular system and spinal cord.
C) Cochlear system and somatosensory cortex.
D) Spinal cord and visual cortex.

B) Vestibular system and spinal cord.

How do vestibulo-spinal reflexes help maintain stability when the body position changes?
A) By increasing blood flow to the muscles.
B) By adjusting muscle tone and initiating rapid movements.
C) By amplifying vestibular signals to the cochlea.
D) By stimulating voluntary muscle control.

B) By adjusting muscle tone and initiating rapid movements.

Which of the following is an essential outcome of vestibulo-spinal reflexes?
A) Improved hearing sensitivity.
B) Blurred vision during head movements.
C) Quick postural adjustments to counteract changes in body orientation.
D) Equalized pressure between the inner and middle ear.

C) Quick postural adjustments to counteract changes in body orientation.

What would happen if vestibulo-spinal reflexes were impaired?
A) The individual would experience hearing loss.
B) Balance and postural stability would be compromised.
C) Visual processing in the retina would slow down.
D) Head movements would become restricted

B) Balance and postural stability would be compromised.

What is the primary function of the central vestibular system?
A) To process auditory signals from the cochlea.
B) To integrate sensory information to maintain balance and spatial orientation.
C) To regulate endolymph flow in the semicircular canals.
D) To detect linear acceleration through otolith organs.

B) To integrate sensory information to maintain balance and spatial orientation.

Which sensory systems contribute to the central vestibular system for balance?
A) Vestibular organs, visual system, and proprioceptive system.
B) Cochlear system, auditory cortex, and visual system.
C) Otolith organs, semicircular canals, and cochlear duct.
D) Visual cortex, spinal cord, and tympanic membrane.

A) Vestibular organs, visual system, and proprioceptive system.

Why is multisensory integration important for the central vestibular system?
A) It enhances the detection of sound waves.
B) It allows the brain to create a cohesive representation of the body’s position and movement within the environment.
C) It increases the frequency of neural impulses in the auditory nerve.
D) It equalizes pressure between the inner and middle ear.

B) It allows the brain to create a cohesive representation of the body’s position and movement within the environment.

What are the three balance disorders?

• BPPV (Benign paroxysmal positional vertigo)

• Vestibular neuritis

• Meniere’s Disease

What is BPPV?

Problem in the otolith organs that leads to vertigo

What is Vestibular neuritis?

inflammatory condition affecting the vestibular nerve

what is Meniere’s Disease

chronic inner ear disorder that causes tinnitus, hearing
loss, and vertigo

Select the primary function(s) of the vestibulo-spinal reflex:

Coordinating muscle contractions for postural control