Lesson 3: Audition

Question 1

What structures make up the Inner Ear?

(A) Malleus, Incus, and Stapes
(B) Pinna, Auditory Canal, and Tympanic Membrane
(C) Semicircular Canals, and Cochlea
(D) Stapes, Pinna, Auditory Canal, and Oval Window

Answer 1

(C) Semicircular Canals, and Cochlea

The Semicircular Canals, and Cochlea make up the Inner Ear.

Question 2

True or False? In addition to the cochlea, the brain uses tectorial tuning to distinguish between high and low frequency sounds.

Answer 2

False. The brain uses Tonotopic Mapping to distinguish between high and low frequency sounds.

Question 3

For audition to occur, the stimulus, _________________, must be present and the receptors, __________________, must transduce the stimulus to neural signals.

(A) Pressurized sound waves, Pressurized sound waves
(B) Pressurized sound waves, Hair Cells
(C) Hair Cells, Hair Cells
(D) Hair Cells, Pressurized Sound Waves

Answer 3

(B) Pressurized sound waves, Hair Cells

For audition to occur, Pressurized Sound Waves must be present and Hair Cells must transduce the stimulus to neural signals.

Question 4

Describe how a pressurized sound wave is formed as someone claps their hands?

Answer 4

When someone goes to clap their hands, there are many air molecules between their hands. As the hands get closer, there is less space for the air molecules to move and they thus become compressed. This compression causes the air molecules to become pressurized and thus to relieve this pressure, the air molecules try to escape. This escape of air molecules causes areas of high and low pressure which are known as pressurized sound waves.

Question 5

Sound waves are represented graphically by peaks and troughs. If a wave has a high wavelength, its peaks must be:

(A) close to each other.
(B) far away from each other.
(C) very tall.
(D) very short.

Answer 5

(B) far away from each other.

If a wave has a high wavelength, its peaks must be far away from each other.

Question 6

What is the relationship between the frequency and wavelength of a sound wave?

(A) Proportional
(B) Inverse
(C) Linear
(D) Exponential

Answer 6

(B) Inverse

As the frequency of a sound wave increases, the wavelength decreases. Likewise, as the frequency of a sound wave decreases, the wavelength increases.

Question 7

Sound waves are discriminated and sorted by its frequency inside the fluid-filled cochlea. Would a lower or higher frequency sound wave travel farther into the cochlea?

Answer 7

Sound waves of a lower frequency would travel farther into the cochlea.

Question 8

In a crowded emergency room, many different voices and sounds combine to make complex sound waves. How does the auditory system break down complex sound waves into its component parts?

Answer 8

Since the complex sound waves are made of components with different frequencies, in the cochlea, the different components will travel to different lengths and stimulate hair cells on different parts of the cochlea.

Question 9

The _______ funnels sound into the ___________, where it will travel to the _______________, where the sound waves are then converted into ossicle vibrations.

To fill in the blanks, please choose 3 from the following options:

• Semicircular Canals
• Pinna
• Tympanic Membrane (eardrum)
• Auditory Canal
• Stapes

Answer 9

1. Pinna
2. Auditory Canal
3. Tympanic Membrane (eardrum)

The Pinna funnels sound into the Auditory Canal, where it will travel to the Tympanic Membrane, where the sound waves are converted into ossicle vibrations.

Question 10

Put the Auditory Ossicles in order from first to vibrate to last to vibrate?

I. Incus
II. Malleus
III. Stapes

(A) I > II > III
(B) II > I > III
(C) III > II > I
(D) III > I > II

Answer 10

(B) II > I > III

1st. Malleus
2nd. Incus
3rd. Stapes

Question 11

Put these steps of the middle ear audition pathway in order:

I. Malleus, incus and stapes vibrate in that order.
II. Oval window (elliptical window) starts to vibrate and moves cochlear fluid.
III. Tympanic membrane vibrates.

(A) I > II > III
(B) II > I > III
(C) III > II > I
(D) III > I > II

Answer 11

(D) III > I > II

Tympanic membrane vibrates. > Malleus, incus and stapes vibrate in that order. > Oval window (elliptical window) starts to vibrate and moves cochlear fluid.

Question 12

Which structure in the cochlea is responsible for preventing cochlear fluid from returning to the oval window (elliptical window), while simultaneously moving the fluid towards the round window (circular window)?

(A) Cilia (Hair Cells)
(B) Stapes
(C) Organ of Corti
(D) Auditory Nerve

Answer 12

(C) Organ of Corti

The Organ of Corti is responsible for preventing cochlear fluid from returning to the oval window (elliptical window), while simultaneously moving the fluid towards the round window (circular window).

Question 13

In the Cochlea, what structure moves back and forth and is responsible for transmitting an electrical impulse via the auditory nerve to the brain?

(A) Cilia (Hair Cells)
(B) Oval Window
(C) Circular Window
(D) Stapes

Answer 13

(A) Cilia (Hair Cells)

In the cochlea, Cilia or Hair cells move back and forth and are responsible for transmitting an electrical impulse via the auditory nerve to the brain.

Question 14

CRB Which of the following are not one of the areas involved in auditory pathways?

(A) Medial Geniculate Nucleus
(B) Lateral Geniculate Nucleus
(C) Superior Olive
(D) Inferior Colliculus

Answer 14

(B) Lateral Geniculate Nucleus

The LGN is involved in vision. The MGN, Superior Olive, and Inferior Colliculus are all involved in processing auditory information.

Question 15

As the energy of a sound wave traveling through the ear dissipates, what happens to the movement of fluid inside the cochlea?

Answer 15

The movement of fluid inside the cochlea slows down and eventually stops, causing that particular sound to not be transmitted to one’s brain anymore.

Question 16

What structures make up the External/Outer Ear?

(A) Malleus, Incus, and Stapes
(B) Pinna, Auditory Canal, and Tympanic Membrane
(C) Semicircular Canals, and Cochlea
(D) Stapes, Pinna, Auditory Canal, and Oval Window

Answer 16

(B) Pinna, Auditory Canal, and Tympanic Membrane

The Pinna, Auditory Canal, and Tympanic Membrane make up the External/Outer Ear.

Question 17

What structures make up the Middle Ear?

(A) Malleus, Incus, and Stapes
(B) Pinna, Auditory Canal, and Tympanic Membrane
(C) Semicircular Canals, and Cochlea
(D) Stapes, Pinna, Auditory Canal, and Oval Window

Answer 17

(A) Malleus, Incus, and Stapes

The Malleus, Incus, and Stapes (Ossicles) make up the Middle Ear.

Question 18

True or False: The Organ of Corti is composed of two membranes.

Answer 18

True. The Organ of Corti is composed of two membranes, the upper (tectorial) and lower (basilar) membrane.

Question 19

The Basilar Membrane of the Organ of Corti contains Cilia (Hair Cells) known as the ___________.

(A) Hair Bundle
(B) Basilar Group
(C) Tectorial Hairs
(D) Cochlear Knot

Answer 19

(A) Hair Bundle

The Basilar Membrane of the Organ of Corti contains Cilia (Hair Cells) known as the Hair Bundle.

Question 20

CRB True or false? The basilar membrane is covered with hair cells, but those hairs project from the basilar membrane to contact the tectorial membrane.

Answer 20

True. The basilar membrane is covered with hair cells, but those hairs project from the basilar membrane to contact the tectorial membrane.

Question 21

________ are the small filaments that make up the hair bundle of the Organ of Corti and are connected to one another by __________.

(A) auditory nerve, kinocilium
(B) kinocilium, tip links
(C) stereocilia, tip links
(D) cilia, kinocilium

Answer 21

(c) stereocilia, tip links

The Stereocilia are the small filaments that make up the hair bundle of the Organ of Corti, and are connected to one another by Tip Links.

Note that there is one kinocilium and many stereocilia in any given hair bundle, so if asked about many small filaments in one bundle, stereocilia is the best option.

Question 22

The tip link of a kinocilium is attached to the gates of a K+ channel. Explain how an action potential is generated when fluid begins to move inside the cochlea.

Answer 22

When tip links start to be pushed back and forth by fluid movement inside the cochlea, they stretch and allow K+ to enter inside the cell. Voltage-gated Ca2+ cells consequentially become activated, allowing Ca2+ to begin flowing into the cell as well, causing an action potential, which activates the auditory nerve.

Question 23

CRB Based on the previous card, the K+ channels opened by the kinocilium belong to what class of channels?

(A) Ligand gated
(B) Voltage Gated
(C) Mechanically Gated
(D) Voltage Gated with Inactivation State

Answer 23

(C) Mechanically Gated

Because the stretching of tip links is permitting the flow of K+ through the channels, this is a mechanically gated channel.

Question 24

Which structure in the ear allows the Brain to differentiate between 2 different sounds?

(A) Tympanic Membrane
(B) Stapes
(C) Cochlea
(D) Ossicles

Answer 24

(C) Cochlea

The Cochlea allows the Brain to differentiate between 2 different sounds.

Question 25

What refers to the process in which the cochlea distinguishes between varying frequencies and is maintained by the brain?

(A) Frequency Processing
(B) Signal Detection Theory
(C) Parallel Processing
(D) Auditory Processing

Answer 25

(D) Auditory Processing

Auditory Processing refers to the process in which the cochlea distinguishes between varying frequencies and is maintained by the brain.

Question 26

What is the range of Frequencies in terms of Hz that humans can hear?

(A) 10 Hz - 10,000 Hz
(B) 20 Hz - 20,000 Hz
(C) 30 Hz - 30,000 Hz
(D) 40 Hz - 40,000 Hz

Answer 26

(B) 20 Hz - 20,000 Hz

20 Hz - 20,000 Hz is the range of Frequencies that a human can hear.

Question 27

CRB True or false? The loudness of sound is represented by the period of the wavelength, and the pitch is represented by the wavelength.

Answer 27

False. The loudness of sound is represented by the AMPLITUDE of the wavelength, and the pitch is represented by the frequency and wavelength (since these are inversely proportional).

Question 28

CRB True or false? The same sensory neuron going from the ear to the brain firing more or less rapidly would encode a change in the pitch of a sound.

Answer 28

False. The same sensory neuron going from the ear to the brain firing more or less rapidly would encode a change in the LOUDNESS of a sound.

Question 29

CRB Which of the following are proper descriptions of how a change in pitch (with constant loudness) would be encoded by the inner ear?

I. The number of auditory nerves activated would change.
II. The basilar membrane would vibrate in different areas.
III. Different auditory nerves would be activated.

(A) II only
(B) I and II only
(C) II and III only
(D) I, II and III

Answer 29

(C) II and III only

Basilar tuning states that different frequencies (pitches) will increase vibrations at different parts of the basilar membrane. This means different auditory neurons will be activated by different frequencies.

Question 30

_____________ frequency sounds activate the base of the cochlea, while _____________ frequency sounds activate the apex of the cochlea.

(A) High, Low
(B) High, High
(C) Low, High
(D) Low, Low

Answer 30

(A) High, Low

High frequency sounds (1600 Hz) activate the base of the cochlea, while Low frequency sounds (25 Hz) activate the apex of the cochlea.

Question 31

Which structure of the brain receives all auditory information from the cochlea and is separated into regions which detect different frequency sounds?

(A) Occipital Lobe
(B) Cerebral Cortex
(C) Primary Auditory Cortex
(D) Secondary Auditory Cortex

Answer 31

(C) Primary Auditory Cortex

The Primary Auditory Cortex of the brain receives all auditory information from the cochlea and is separated into regions which detect different frequency sounds.

Question 32

Without basilar tuning, humans would not be able to differentiate between sounds. What is the mapping of different frequency sounds in the brain referred to as?

(A) Auditory mapping
(B) Basilar mapping
(C) Tonotopical mapping
(D) Geographical mapping

Answer 32

(C) Tonotopical mapping

Tonotopical mapping refers to the mapping of different frequency sounds in the brain, and thus allows distinct areas in the brain to process distinct frequencies.

Question 33

If there were no cochlear fluid, would audition be possible? How would the hair cells be affected?

Answer 33

Any vibrations from the stapes to the oval window would move air, whose movement would have a significantly smaller effect on hair cells; thus, they wouldn’t reach threshold, making audition impossible.

Question 34

Order the following steps of a Cochlear Implant from first to last:

I. Transmitter sends electrical impulse to the Receiver.
II. Stimulator sends electrical impulse to the Cochlea which converts the electrical impulse to a neural impulse that is sent to the brain.
III. Sound is converted to an electrical impulse by Speech Processor.
IV. Receiver sends electrical impulse to the Stimulator.

(A) I > III > IV > II
(B) III > I > IV > II
(C) II > IV > III > I
(D) IV > II > III > I

Answer 34

(B) III > I > IV > II

Sound is converted to an electrical impulse by Speech Processor > Transmitter sends electrical impulse to the Receiver > Receiver sends electrical impulse to the Stimulator > Stimulator sends electrical impulse to the Cochlea which converts the electrical impulse to a neural impulse that is then sent to the brain.

Question 35

Why can a cochlear implant help patients with sensorineural hearing loss (aka nerve deafness), but not cochlear or downstream nervous issues?

Answer 35

A cochlear implant functions by stimulating the oval window of the cochlea when its transmitter is activated. It can overcome conduction errors from the middle ear, but can’t fix errors downstream of the oval window.

Question 36

CRB True or false? The stapes-oval window junction is similar to a gas-piston system, and the perilymph inside the cochlea is easily compressed by the stapes’ vibrations.

Answer 36

False. The stapes-oval window junction is similar to a gas-piston system. However, liquids are not compressible, so the perilymph moves back and forth within the cochlea.

Question 37

What refers to a change over time of the responsiveness to a constant stimulus and thus represents a down regulation of a sensory receptor in the body?

(A) Amplification
(B) Sensory Adaptation
(C) Feature Detection Theory
(D) Proprioception

Answer 37

(B) Sensory Adaptation

Sensory Adaptation refers to a change over time of the responsiveness to a constant stimulus and thus represents a down regulation of a sensory receptor in the body.

Question 38

Give a real life example of sensory adaptation.

Answer 38

You walk into the library and notice a strong smell, similar to BBQ. After about an hour sitting in the library your smell receptors would no longer notice such a strong smell of BBQ. Mmmm… BBQ…

Question 39

Light hits a photoreceptor in the eye and causes the the cell to fire an action potential. That cell is connected to two other cells, which also fire action potentials. What does this form of up-regulation refer to?

(A) Amplification
(B) Sensory Adaptation
(C) Habituation
(D) Proprioception

Answer 39

(A) Amplification

Because the stimulus, light, caused multiple action potentials to occur, the response to the stimulus is up-regulated and refers to Amplification

Question 40

Why is Sensory adaptation important in terms of cells becoming over excited?

Answer 40

If a cell is overexcited, it can cause damage and most likely cell death. Sensory adaptation is a necessary response by receptors to avoid over-excitement of cells.

Question 41

What is the part of the human brain that is referred to as the map of the human body?

(A) Sensory Strip
(B) Midbrain
(C) Somatosensory Homunculus
(D) Sensory Cortex

Answer 41

(A) Sensory Strip

The Sensory Strip is the part of the parietal lobe that houses the five senses, and can be mapped out as homunculi.

Question 42

Which structure of the brain receives sensory input from the entire human body?

(A) Sensory Strip
(B) Cerebellum
(C) Pons
(D) Medulla

Answer 42

(A) Sensory Strip

The Sensory Strip is the structure of the brain that receives sensory input from the entire human body.

Question 43

Proprioception spindles are often compared to springs. How do these receptors in muscles communicate position to your brain?

Answer 43

These sensors are inside the muscles and will stretch with them. Once stretched, spindles fire signals to the brain, and the combination of spindles from all muscles are integrated, allowing you to subconsciously know your body position.

Question 44

CRB Based on the previous card’s description, which of the following classes of receptors communicate position from your proprioception spindles to your brain?

(A) Mechanoreceptors
(B) Chemoreceptors
(C) Kinesoreceptors
(D) Nociceptors

Answer 44

(A) Mechanoreceptors

Because those receptors in the muscle spindles are activated by stretching (mechanical stress), they are mechanoreceptors.

Question 45

CRB Which of the following are also types of proprioceptors?

I. Golgi tendon organs
II. Ossicle receptors
III. Joint capsule receptors

(A) I only
(B) I and II only
(C) I and III only
(D) I, II and III

Answer 45

(C) I and III only

Common proprioceptors are:
I. Golgi Tendon organs
II. Proprioception spindles
III. Joint capsule receptors

Question 46

CRB Which part of the Central Nervous System would use this information from proprioceptors to improve its coordination?

(A) Substantia Nigra
(B) Cerebellum
(C) Cerebrum
(D) Spinal Column

Answer 46

(B) Cerebellum

The Cerebellum, which coordinates movement, would integrate information from proprioceptors.

Question 47

In which part of cerebral cortex is the sensory strip located?

(A) Frontal Lobe
(B) Parietal Lobe
(C) Temporal Lobe
(D) Occipital Lobe

Answer 47

(B) Parietal Lobe

The Sensory Strip is located in the Parietal Lobe.

Question 48

What are the main differences between proprioception and kinesthesia?

Answer 48

Proprioception is more subconscious and cognitive, like a general awareness of one’s balance/position.

Kinesthesia is more behavioral, with the body detecting its movements and consciously improving its movements.

Question 49

Both nociception and thermoception (pain and temperature sensation, respectively) use TrpV1 receptors. How do these receptors convert cellular damage into neural signals?

Answer 49

When a cell is damaged, it releases chemical signals that diffuse to the nearest TrpV1 receptor.

Question 50

True or false? A-Beta (A-B) fibers are the fastest, while C fibers are the slowest, due to their different levels of myelination.

Answer 50

True. A-Beta (A-B) fibers are the fastest, while C fibers are the slowest, due to their different levels of myelination.

Question 51

The three types of TrpV1 fibers, A-B, A-D, and C vary in size due to different levels of myelination. How does their relative myelination affect their function?

Answer 51

The more myelinated a fiber is, the wider the axon is. This increases conductance by decreasing resistance, so the more myelinated fibers transmit their messages faster.

Question 52

When eating spicy foods, people can feel pain as their TrpV1 receptors are activated. Why can capsaicin and similar chemicals activate these receptors?

Answer 52

TrpV1 receptors are chemical sensors, so the capsacin molecules must be similar in structure to molecules released by cellular damage. Thus, spicy foods might feel “painful”