Chapter 7
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pitch
A perceptual dimension of sound; corresponds to the fundamental frequency.
hertz/Hz
Cycles per second.
loudness
A perceptual dimension of sound; corresponds to intensity.
timbre
A perceptual dimension of sound; corresponds to complexity.
tympanic membrane
The eardrum.
ossicle
One of the three bones of the middle ear.
malleus
The "hammer"; the first of the three ossicles.
incus
The "anvil"; the second of the three ossicles.
stapes
The "stirrup" the last of the three ossicles.
cochlea
The snail-shaped structure of the inner ear that contains the auditory transducing mechanisms.
oval window
An opening in the bone surrounding the cochlea that reveals a membrane, against which the baseplate of the stapes presses, transmitting sound vibrations into the fluid within the cochlea.
organ of Corti
The sensory organ on the basilar membrane that contains the auditory hair cells.
hair cell
The receptive cell of the auditory apparatus.
Deiters's cell
A supporting cell found in the organ of Corti; sustains the auditory hair cells.
basilar membrane
A membrane in the cochlea of the inner ear; contains the organ of Corti.
tectorial membrane
A membrane located above the basilar membrane; serves as a shelf against which the cilia of the auditory hair cells move.
round window
An opening in the bone surrounding the cochlea of the inner ear that permits vibrations to be transmitted, via the oval window, into the fluid in the cochlea.
cilium
A hairlike appendage of a cell involved in movement or in transducing sensory information; found on the receptors in the auditory and vestibular system.
tip link
Elastic filaments that attach the tip of one cilium to the side of the adjacent cilium.
insertional plaque
The point of attachment of a tip link to a cilium.
cochlear nerve
The branch of the auditory nerve that transmits auditory information from the cochlea to the brain.
olivocochlear bundle
A bundle of efferent axons that travel from the olivary complex of the medulla to the auditory hair cells on the cochlea.
cochlear nucleus
One of a group of nuclei in the medulla that receive auditory information from the cochlea.
superior olivary complex
A group of nuclei in the medulla; involved with auditory functions, including localization of the source of sounds.
lateral lemniscus
A band of fibers running rostrally through the medulla and pons; carries fibers of the auditory system.
tonotopic representation
A topographically organized mapping of different frequencies of sound that are represented in a particular region of the brain.
place code
The system by which information about different frequencies is coded by different locations on the basilar membrane.
cochlear implant
An electronic device surgically implanted in the inner ear that can enable deaf people to hear.
rate code
The system by which information about different frequencies is coded by the rate of firing of neurons in the auditory system.
fundamental frequency
The lowest, and usually most intense, frequency of a complex sound; most often perceived as the sound's basic pitch.
overtone
The frequency of complex tones that occurs at multiples of the fundamental frequency.
phase difference
The difference in arrival times of sound waves at each of the eardrums.
vestibular sac
One of a set of two receptor organs in each inner ear that detect changes in the tilt of the head.
semicircular canal
One of the three ringlike structures of the vestibular apparatus that detect changes in head rotation.
utricle
One of the vestibular sacs.
saccule
One of the vestibular sacs.
ampulla
An enlargement in a semicircular canal; contains the cupula and the crista.
cupula
A gelatinous mass found in the ampulla of the semicircular canals; moves in response to the flow of the fluid in the canals.
vestibular ganglion
A nodule on the vestibular nerve that contains the cell bodies of the bipolar neurons that convey vestibular information to the brain.
cutaneous sense
One of the somatosenses; includes sensitivity to stimuli that involve the skin.
kinesthesia
Perception of the body's own movements.
organic sense
A sense modality that arises from receptors located within the inner organs of the body.
glabrous skin
Skin that does not contain hair; found on the palms and soles of the feet.
Ruffini corpuscle
A vibration-sensitive organ located in hairy skin.
Pacinian corpuscle
A specialized, encapsulated somatosensory nerve ending that detects mechanical stimuli, especially vibrations.
Meissner's corpuscle
The touch-sensitive end organs located in the papillae, small elevations of the dermis that project up into the epidermis.
Merkel's disk
The touch-sensitive end organs found at the base of the epidermis, adjacent to sweat ducts.
prostaglandin
A member of a family of fatty acid derivatives that serve as hormones; first discovered in the prostate gland; involved in many physiological processes, including pain perception.
phantom limb
Sensations that appear to originate in a limb that has been amputated.
nucleus raphe magnus
A nucleus of the raphe that contains serotonin-secreting neurons that project to the dorsal gray matter of the spinal cord via the dorsolateral columns and is involved in analgesia produced by opiates.
gustducin
A G protein that plays a vital role in the transduction of sweetness and bitterness.
umami
The taste sensation produced by glutamate.
chorda tympani
A branch of the facial nerve that passes beneath the eardrum; conveys taste information from the anterior part of the tongue and controls the secretion of some salivary glands.
nucleus of the solitary tract/NST
A nucleus of the medulla that receives information from visceral organs and from the gustatory system.
olfactory epithelium
The epithelial tissue of the nasal sinus that covers the cribriform plate; contains the cilia of the olfactory receptors.
olfactory bulb
The protrusion at the end of the olfactory nerve; receives input from the olfactory receptors.
mitral cell
A neuron located in the olfactory bulb that receives information from olfactory receptors; axons of mitral cells bring information to the rest of the brain.
olfactory glomerulus
A bundle of dendrites of mitrial cells and the associated terminal buttons of the axons of olfactory receptors.
More terms
58
skeletal muscle
One of the striated muscles attached to bones.
flexion
A movement of a limb that tends to bend its joints; opposite of extension.
extension
A movement of a limb that tends to straighten its joints; the opposite of flexion.
extrafusal muscle fiber
One of the muscle fibers that are responsible for the force exerted by contraction of a skeletal muscle.
alpha motor neuron
A neuron whose axon forms synapses with extrafusal muscle fibers of a skeletal muscle; activation contracts the muscle fibers.
intrafusal muscle fiber
A muscle fiber that functions as a stretch receptor, arranged parallel to the extrafusal muscle fibers, thus detecting changes in muscle length.
gamma motor neuron
A neuron whose axons form synapses with intrafusal muscle fibers.
motor unit
A motor neuron and its associated muscle fibers.
myofibril
An element of muscle fibers that consists of overlapping strands of actin and myosin; responsible for muscular contractions.
actin
One of the proteins (with myosin) that provide the physical basis for muscular contraction.
myosin
One of the proteins (with actin) that provide the physical basis for muscular contraction.
striated muscle
Skeletal muscle; muscle that contains striations.
neuromuscular junction
The synapse between the terminal buttons of an axon and a muscle fiber.
motor endplate
The postsynaptic membrane of a neuromuscular junction.
endplate potential
The postsynaptic potential that occurs in the motor endplate in response to release of acetylcholine by the terminal button.
Golgi tendon organ/GTO
The receptor organ at the junction of the tendon and muscle that is sensitive to stretch.
smooth muscle
Nonstriated muscle innervated by the autonomic nervous system, found in the walls of blood vessels, in the reproductive tracts, in sphincters, within the eye, in the digestive system, and around hair follicles.
cardiac muscle
The muscle responsible for the contraction of the heart.
monosynaptic stretch reflex
A reflex in which a muscle contracts in response to its being quickly stretched; involves a sensory neuron and a motor neuron, with one synapse between them.
decerebrate
Describes an animal whose brain stem has been transected.
decerebrate rigidity
Simultaneous contraction of agonistic and antagonistic muscles; caused by decerebration or damage to the reticular formation.
clasp-knife reflex
A reflex that occurs when force is applied to flex or extend the limb of an animal showing decerebrate rigidity; resistance is replaced by sudden relaxation.
agonist
A muscle whose contraction produces or facilitates a particular movement.
antagonist
A muscle whose contraction resists or reverses a particular movement.
somatotopic organization
A topographically organized mapping of parts of the body that are represented in a particular region of the brain.
supplementary motor area
A region of motor association cortex of the dorsal and dorsomedial frontal lobe, rostral to the primary motor cortex.
premotor cortex
A region of motor association cortex of the lateral frontal lobe, rostral to the primary motor cortex.
prefrontal cortex
The neocortex of the frontal lobes rostral to the supplementary motor area and premotor cortex.
lateral group
The corticospinal tract, the corticobulbar tract, and the rubrospinal tract.
ventromedial group
The vestibulospinal tract, the tectospinal tract, the reticulospinal tract, and the ventral corticospinal tract.
corticospinal tract
The system of axons that originates in the motor cortex and terminates in the ventral gray matter of the spinal cord.
pyramidal tract
An alternate term for the corticospinal tract.
lateral corticospinal tract
The system of axons that originates in the motor cortex and terminates in the contralateral ventral gray matter of the spinal cord; controls movements of the distal limbs.
ventral corticospinal tract
The system of axons that originates in the motor cortex and terminates in the ipsilateral ventral gray matter of the spinal cord; controls movements of the upper legs and trunk.
corticobulbar pathway
A bundle of axons from the motor cortex to the fifth, seventh, ninth, tenth, eleventh, and twelfth cranial nerves; controls movements of the face, neck, tongue, and parts of the extraocular eye muscles.
rubrospinal tract
The system of axons that travels from the red nucleus to the spinal cord; controls independent limb movements.
corticorubral tract
The system of axons that travels from the motor cortex to the red nucleus.
vestibulospinal tract
A bundle of axons that travels from the vestibular nuclei to the gray matter of the spinal cord; controls postural movements in response to information from the vestibular system.
tectospinal tract
A bundle of axons that travels from the tectum to the spinal cord; coordinates head and trunk movements with eye movements.
reticulospinal tract
A bundle of axons that travels from the reticular formation to the gray matter of the spinal cord; controls the muscles responsible for postural movements.
apraxia
Difficulty in carrying out purposeful movements, in the absence of paralysis or muscular weakness.
callosal apraxia
An apraxia of the left hand caused by damage to the anterior corpus callosum.
sympathetic apraxia
A movement disorder of the left hand caused by damage to the left frontal lobe; similar to callosal apraxia.
left parietal apraxia
An apraxia caused by damage to the left parietal lobe; characterized by difficulty in producing sequences of movements by verbal request or in imitation of movements made by someone else.
constructional apraxia
Difficulty in drawing pictures or diagrams or in making geometrical constructions of elements such as building blocks or sticks; caused by damage to the right parietal lobe.
caudate nucleus
A telencephalic nucleus; one of the input nuclei of basal ganglia along with the putamen; involved with control of voluntary movement.
putamen
A telencephalic nucleus; one of the input nuclei of the basal ganglia along with the caudate nucleus; involved with control of voluntary movement.
globus pallidus
A telencephalic nucleus; the primary output nucleus of the basal ganglia; involved with control of voluntary movement.
ventral anterior nucleus
One of the two thalamic nuclei that receive projections from the basal ganglia and send projections to the motor cortex.
ventrolateral nucleus
One of the two thalamic nuclei that receive projections from the basal ganglia and send projections to the motor cortex.
Huntington's chorea
An fatal inherited disorder that causes degeneration of the caudate nucleus and putamen; characterized by uncontrollable jerking movements, writhing movements, and dementia.
flocculonodular lobe
A region of the cerebellum; involved in control of postural reflexes.
vermis
The portion of the cerebellum located at the midline; receives somatosensory information and helps control the vestibulospinal and reticulospinal tracts through its connections with the fastigial nucleus.
fastigial nucleus
A deep cerebellar nucleus; involved in the control of movement by the reticulospinal and vestibulospinal tracts.
interposed nuclei
A set of deep cerebellar nuclei; involved in the control of the rubrospinal system.
pontine nucleus
A large nucleus in the pons that serves as an important source of input to the cerebellum.
dentate nucleus
A deep cerebellar nucleus; involved in the control of rapid, skilled movements by the corticospinal and rubrospinal systems.
mesencephalic locomotor region
A region of the reticular formation of the midbrain whose stimulation causes alternating movements of the limbs normally seen during locomotion.