9 - Hearing, Vestibular Perception, Taste, and Smell Flashcards
External ear
The part of the ear that we readily see (the pinna) and the canal that leads to the eardrum
Transduction
The conversion of one form of energy to another
Pinna
The external part of the ear
Pure tone
A tone with a single frequency of vibration
Amplitude
The force sound exerts per unit area, usually measured as dynes per square centimeter
Loudness
The subjective experience of the pressure level of a sound
Frequency
The number of cycles per second in a sound wave, measured in hertz (Hz)
Hertz (Hz)
Cycles per second, as of an auditory stimulus
Pitch
A dimension of auditory experience in which sounds vary from low to high
Fundamental
The predominant frequency of an auditory tone or a visual scene
Harmonics
Multiples of a particular frequency called the fundamental
Timbre
The characteristic sound quality of a musical instrument, as determined by the relative intensities of its various harmonics
Fourier analysis
The analysis of a complex pattern into the sum of sine waves
Decibel (dB)
A measure of sound intensity
Middle ear
The cavity between the tympanic membrane and the cochlea
Ossicles
Three small bones (incus, malleus, and stapes) that transmit sound across the middle ear, from the tympanic membrane to the oval window
Tympanic membrane
Also called eardrum. The partition between the external ear and the middle ear
Oval window
The opening from the middle ear to the inner ear
Malleus
Latin for “hammer.” A middle-ear bone that is connected to the tympanic membrane
Incus
Latin for “anvil.” A middle-ear bone situated between the malleus and the stapes
Stapes
Latin for “stirrup.” A middle-ear bone that is connected to the oval window
Tensor tympani
The muscle attached to the malleus that modulates mechanical linkage to protect the delicate receptor cells of the inner ear from damaging sounds
Stapedius
A middle-ear muscle that is attached to the stapes
Inner ear
The cochlea and vestibular apparatus
Cochlea
A snail-shaped structure in the inner ear that contains the primary receptor cells for hearing
Scala vestibuli
Also called vestibular canal. One of three principle canals running along the length of the cochlea
Scala media
Also called middle canal. The central of the three spiraling canals inside the cochlea, situated between the scala vestibuli and the scala tympani
Scala tympani
Also called tympanic canal. One of three principle canals running along the length of the cochlea
Round window
A membrane separating the cochlear duct from the middle-ear cavity
Organ of Corti
A structure in the inner ear that lies on the basilar membrane of the cochlea and contains the hair cells and terminations of the auditory nerve
Hair cell
One of the receptor cells for hearing in the cochlea
Basilar membrane
A membrane in the cochlea that contains the principle structures involved in auditory transduction
Inner hair cell (IHC)
One of the two types of receptor cells for hearing in the cochlea
Outer hair cell (OHC)
One of the two types of receptor cells for hearing in the cochlea
Stereocilium
A relatively stiff hair that protrudes from a hair cell in the auditory or vestibular system
Tectorial membrane
A membrane that sits atop the organ of Corti in the cochlear duct
Tip link
A fine, threadlike fiber that runs along and connects the tips of stereocilia
Cochlear amplifier
The mechanism by which the cochlea is physically distorted by outer hair cells in order to “tune” the cochlea to be particularly sensitive to some frequencies more than others
Otoacoustic emission
A sound produced by the cochlea itself, either spontaneously or in response to an environmental noise
Tuning curve
A graph of responses of a single auditory nerve fiber or neuron to sounds that vary in frequency and intensity
Vestibulocochlear nerve
Cranial nerve VIII, which runs from the cochlea to the brainstem auditory nuclei
Cochlear nuclei
Brainstem nuclei that receive input from auditory hair cells and send output to the superior olivary complex
Superior olivary nuclei
Brainstem nuclei that receive input from both right and left cochlear nuclei, and provide the first binaural analysis of auditory information
Inferior colliculi
Paired gray matter structures of the dorsal midbrain that receive auditory information
Medial geniculate nuclei
Nuclei in the thalamus that receive input from the inferior colliculi and send output to the auditory cortex
Tonotopic organization
A major organizational feature in auditory systems in which neurons are arranged as an orderly map of stimulus frequency, with cells responsive to high frequencies located at a distance from those responsive to low frequencies
Minimal discriminable frequency difference
The smallest change in frequency that can be detected reliably between two tones
Place theory
A theory of frequency discrimination stating that pitch perception depends on the place of maximal displacement of the basilar membrane produced by a sound
Volley theory
A theory of frequency discrimination that emphasizes the relation between sound frequency and the firing pattern of nerve cells
Ultrasound
High-frequency sound; in general, above the threshold for human hearing, at about 20,000 Hz.
Infrasound
Very low frequency sound; in general, below the threshold for human hearing, at about 20 Hz.
Binaural
Pertaining to two ears
Intensity differences
Perceived differences in loudness between the two ears, which can be used to localize a sound source
Latency differences
Differences between the two ears in the time of the arrival of a sound, which can be employed by the nervous system to localize sound sources
Duplex theory
A theory that we localize sound by combining information about intensity differences and latency differences between the two ears
Coincidence detector
A device that senses the co-occurrence of two events
Spectral filtering
Alteration of the amplitude of some, but not all, frequencies in a sound
Monaural
Pertaining to one ear
Amusia
A disorder characterized by the inability to discern tunes accurately
Diffusion tensor imaging (DTI)
A special use of MRI that takes advantage of the differences in how water molecules are constrained in myelin to reveal axonal tracts connecting brain regions
Conduction deafness
A hearing impairment that is associated with pathology of the external-ear or middle-ear cavities
Sensorineural deafness
A hearing impairment that originates from cochlear or auditory nerve lesions
Ototoxic
Toxic to the ears, especially the middle or inner ear
Tinnitus
A sensation of noises or ringing in the ears
Central deafness
A hearing impairment that is related to lesions in auditory pathways or centers, including sites in the brainstem, thalamus, or cortex
Word deafness
The specific inability to hear words, although other sounds can be detected
Cortical deafness
A hearing impairment that is caused by a fault or defect in the cortex
Cochlear implant
An electromechanical device that detects sounds and selectively stimulates nerves in different regions of the cochlea via surgically implanted electrodes
Auditory brainstem implant (ABI)
A type of auditory prosthesis in which implanted microphones directly stimulate the auditory nuclei of the brainstem rather than the cochlea
Semicircular canal
One of the three fluid-filled tubes in the inner ear that are part of the vestibular system. Each of the tubes, which are at right angles to each other, detects angular acceleration
Utricle
A small, fluid-filled sac in the vestibular system above the saccule that responds to static positions of the head
Saccule
A small, fluid-filled sac under the utricle in the vestibular system that responds to static positions of the head
Ampulla
An enlarged region of each semicircular canal that contains the receptor cells (hair cells) of the vestibular system
Otolith
A small crystal on the gelatinous membrane in the vestibular system
Lateral-line system
A sensory system, found in many kinds of fish and some amphibians, that informs the animal of water motion in relation to the body surface
Cupula
A small gelatinous column that forms part of the lateral-line system of aquatic animals and also occurs within the vestibular system of mammals
Vestibular nuclei
Brainstem nuclei that receive information from the vestibular organs through cranial nerve VIII (the vestibulocochlear nerve)
Vestibulo-ocular reflex (VOR)
The brainstem mechanism that maintains gaze on a visual object despite movements of the head
Motion sickness
The experience of nausea brought on by unnatural passive movement, as in a car or boat
Sensory conflict theory
A theory of motion sickness suggesting that discrepancies between vestibular information and visual information simulate food poisoning and therefore trigger nausea
Papilla
A small bump that projects from the surface of the tongue. Papillae contain most of the taste receptor cells.
Taste bud
A cluster of 50-150 cells that detect tastes. Taste buds are found in papillae
Taste pore
The small aperture through which tastant molecules are able to access the sensory receptors of the taste bud
Tastant
A substance that can be tasted
Circumvallate papillae
One of three types of small structures on the tongue, located in the back, that contain taste receptors
Foliate papillae
One of the three types of small structures on the tongue, located along the sides, that contain taste receptors
Fungiform papillae
One of three types of small structures on the tongue, located in the front, that contain taste receptors
T1R
A family of taste receptor proteins that, when a particular members heterodimerize, form taste receptors for sweet flavors and umami flavors
T2R
A family of bitter taste receptors
Umami
One of the five basic tastes (along with salty, sour, sweet, and bitter), probably mediated by amino acids in foods
Gustatory system
The taste system
Pattern coding
Coding of information in sensory systems based on the temporal pattern of action potentials
Labeled lines
The concept that each nerve input to the brain reports only a particular type of information
Anosmia
The inability to smell
Olfactory epithelium
A sheet of cells, including olfactory receptors, that lines the dorsal portion of the nasal cavities and adjacent regions, including the septum that separates the left and right nasal cavities
Cilium
A hairlike extension
Dendritic knob
A portion of olfactory receptor cells present in the olfactory epithelium
Turbinates
Complex shapes underlying the olfactory mucosa that direct inspired air over receptor cells
Olfactory bulb
An anterior projection of the brain that terminates in the upper nasal passages and, through small openings in the skull, provides receptors for smell
Glomerulus
A complex arbor of dendrites from a group of olfactory cells
Mitral cell
A type of cell in the olfactory bulb that conducts smell information from the glomeruli to the rest of the brain
Pheromone
A chemical signal that is released outside the body of an animal and affects other members of the same species
Vomeronasal system
A specialized chemical detection system that detects pheromones and transmits information to the brain
Vomeronasal organ (VNO)
A collection of specialized receptor cells, near to but separate from the olfactory epithelium, that detect pheromones and send electrical signals to the accessory olfactory bulbs in the brain
Trace amine-associated receptors (TAARs)
A family of probable pheromone receptors produced by neurons in the main olfactory epithelium
