Chapter 11

Question 1

Ampulla

Answer 1

The bulge along a semicircular canal, which contains the hair cells that transduce rotation.

Question 2

Attenuation Reflex

Answer 2

The contraction of muscles in the middle ear, resulting in a reduction in auditory sensitivity.

Question 3

Audition

Answer 3

The sense of hearing.

Question 4

Auditory Canal

Answer 4

A channel leading from the pinna to the tympanic membrane; the entrance to the internal ear.

Question 5

Auditory-Vestibular Nerve

Answer 5

Cranial nerve VIII, consisting of axons projecting from the spiral ganglion to the cochlear nuclei

Question 6

Basilar Membrane

Answer 6

A membrane separating the scala tympani and scala media in the cochlea in the inner ear.

Question 7

Characteristic Frequency

Answer 7

The sound frequency to which a neuron in the auditory system gives its greatest response.

Question 8

Cochlea

Answer 8

A spiral bony structure in the inner ear that contains the hair cells that transduce sound.

Question 9

Cochlear Amplifier

Answer 9

Outer hair cells, including the motor proteins in the outer hair cell membrane, that amplify displacements of the basilar membrane in the cochlea.

Question 10

Dorsal Cochlear Nucleus

Answer 10

A nucleus in the medulla that receives afferents from the spiral ganglion in the cochlea of the inner ear.

Question 11

Duplex Theory of Sound Localization

Answer 11

The principle that two schemes function in sound localization: interaural time delay at low frequencies and interaural intensity difference at high frequencies.

Question 12

Endocochlear Potential

Answer 12

The voltage difference between the endolymph and the perilymph, about 80 mV.

Question 13

Endolymph

Answer 13

The fluid that fills the scala media in the cochlea of the inner ear, containing high K+ and low Na+ concentrations.

Question 14

Eustachian Tube

Answer 14

An air-filled tube connecting the middle ear to the nasal cavities.

Question 15

Frequency

Answer 15

The number of sound waves or other discrete events per second, expressed in hertz (Hz).

Question 16

Hair Cell

Answer 16

An auditory cell that transduces sound into a change in membrane potential or a vestibular cell that transduces head movements into a change in membrane potential.

Question 17

Hertz (Hz)

Answer 17

The unit of sound frequency equivalent to cycles per second.

Question 18

Inferior Colliculus

Answer 18

A nucleus in the midbrain from which all ascending auditory signals project to the medial geniculate nucleus.

Question 19

Inner Ear

Answer 19

The cochlea, which is part of the auditory system, plus the labyrinth, which is part of the vestibular system.

Question 20

Inner Hair Cell

Answer 20

An auditory cell located between the modiolus and the rods of Corti; the primary transducer of sound into an electrochemical signal.

Question 21

Intensity

Answer 21

The amplitude of a sound wave. Sound intensity is the amplitude of the pressure differences in a sound wave that perceptually determines loudness.

Question 22

Medial Geniculate Nucleus (MGN)

Answer 22

A relay nucleus in the thalamus through which all auditory information passes on its way from the inferior colliculus to the auditory cortex.

Question 23

Middle Ear

Answer 23

The tympanic membrane plus the ossicles.

Question 23

Organ of Corti

Answer 23

An auditory receptor organ that contains hair cells, rods of Corti, and supporting cells.

Question 24

Ossicle

Answer 24

One of three small bones in the middle ear.

Question 25

Ololith Organ

Answer 25

The utricle or the saccule, organs of the vestibular labyrinth in the inner ear that transduce head tilt and acceleration.

Question 26

Outer Hair Cell

Answer 26

An auditory receptor cell located farther from the modiolus than the rods of Corti in the inner ear.

Question 27

Outer Ear

Answer 27

The pinna plus the auditory canal.

Question 28

Oval Window

Answer 28

A hole in the bony cochlea of the inner ear, where movement of the ossicles is transferred to movement of the fluids in the cochlea.

Question 29

Perilymph

Answer 29

The fluid that fills the scala vestibuli and scala tympani in the cochlea in the inner ear, containing low K+ and high Na+ concentrations.

Question 30

Phase Locking

Answer 30

The consistent firing of an auditory neuron at the same phase of a sound wave.

Question 31

Pinna

Answer 31

The funnel-shaped outer ear, consisting of cartilage covered by skin.

Question 32

Pitch

Answer 32

The perceptual quality of a sound determined by the sound’s frequency.

Question 33

Primary Auditory Cortex

Answer 33

Brodmann’s area 41 on the superior surface of the temporal lobe; also called A1.

Question 34

Round Window

Answer 34

A membrane-covered hole in the bony cochlea of the inner ear that is continuous with the scala tympani in the cochlea

Question 35

Semicircular Canal

Answer 35

A component of the vestibular labyrinth in the inner ear that transduces head rotation.

Question 36

Spiral Ganglion

Answer 36

A collection of neurons in the modiolus of the cochlea that receives input from hair cells and sends output to the cochlear nuclei in the medulla via the auditory nerve.

Question 37

Stereocilium

Answer 37

A hairlike cilium attached to the top of a hair cell in the inner ear.

Question 38

Stria Vascularis

Answer 38

A specialized endothelium lining one wall of the scala media and responsible for secreting endolymph.

Question 39

Superior Olive

Answer 39

A nucleus in the caudate pons that receives afferents from the cochlear nuclei and sends efferents to the inferior colliculus; also called superior olivary nucleus.

Question 40

Tectorial Membrane

Answer 40

A sheet of tissue that hangs over the organ of Corti in the cochlea in the inner ear.

Question 41

Tonotopy

Answer 41

The systematic organization within an auditory structure on the basis of characteristic frequency.

Question 42

Tympanic Membrane

Answer 42

A membrane at the internal end of the auditory canal that moves in response to variations in air pressure; also called eardrum.

Question 43

Ventral Cochlear Nucleus

Answer 43

A nucleus in the medulla that receives afferents from the spiral ganglion in the cochlea of the inner ear.

Question 44

Vestibular Nucleus

Answer 44

A nucleus in the medulla that receives input from the vestibular labyrinth of the inner ear.

Question 44

Vestibular Labyrinth

Answer 44

A part of the inner ear specialized for the detection of head motion; consists of the otolith organs and semicircular canals.

Question 45

Vestibular System

Answer 45

The neural system that monitors and regulates the sense of balance and equilibrium.

Question 46

Vestibulo-ocular reflex (VOR)

Answer 46

A reflexive movement of the eyes stimulated by rotational movements of the head; stabilizes the visual image on the retinas.

Question 47

Volley Principle

Answer 47

The idea that high sound frequencies are represented in the pooled activity of a number of neurons, each of which fires in a phase-locked manner.