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291 Cards in this Set
- Front
- Back
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conscious perception and voluntary responses of skeletal muscles |
somatic nervous system |
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transmembrane protein receptor |
protein in cell membrane that mediates a phsyiological change in a neuron - activated by ligands |
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receptor cells calssified by |
cell type, position, function - transduction of stmuli |
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structural receptor types |
1. free nerve ending with dendrites embedded in tissue that would receive a sensation 2. encapsulated ending endings are encapsulated in ct that are sensitive 3. receptor cell are specific |
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cells in retina that respond to light stimuli are |
photoreceptor these are specialized receptor cells - these release neurotransmitters onto a bipolar cell |
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exteroceptor |
receptor located near stimulus in external environment - somatosensory receptor on skin |
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interoceptor |
interprets timli from internal organs and tissues - aorta or arotid sinus |
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proprioceptor |
receptor near moving part of body - muscle - interprets position of tissue as they move |
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chemoreceptor |
interprets chemical stimuli - taste or smell |
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osmoreceptors |
solute concentrations of body fluids |
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nociceptor |
how pain is recognized |
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physical stimuli (touch, vibration, sounds and balance) are interpreted through |
mechanoreceptor |
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general sense |
distributed throughout the body and has receptor cells within the structures of other organs - mechanorecptors - touch, proprioception (body movement), kinesthesia(body movement) or visceral sense |
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special sense |
one that has a specific organ devoted to it - eye, inner ear, tongue, nose |
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each sense is a |
sensory modality |
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submodalities |
larger sense |
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gustation |
submodalities of taste - sweet, salty, sour, bitter, umami(savory), lipids - stratified squamous epithelium - papillae contain gustatory transduction |
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4 types of papillae |
cicumvallate, foliate, filiform, fungiform - in papillae are taste buds that have gustatory receptor cells - can activate sensory neurons in facial, glossopharyngeal, and vagus cranial nerves |
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salt taste |
na+ high out of gustatory cells |
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sour taste |
h+ high and triggers depolarization |
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tastes from food bind to |
g protein receptors |
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alkaloid |
bitter tasting molecule - nitrogen containing molecules that are commonly in bitter plant products like coffee, hops, tannins, tea, aspirin - makes plant protected from microbe and herbivores - gag relfex - posterior tongue - complex activation hyper activate or depolarize g protein |
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umami |
savory - amino acid l glutamate activates g protein - umami is perceived while eating protein rich foods |
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facial nerve connects to taste buds in |
ant third of tongue |
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glossopharyngeal nere connets to taste buds in |
pos 2/3 of tongue
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vagus nerve connects to taste buds in extreme post of tongue, |
more sensitive to noxious stimuli like bitterness |
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olfaction |
smell - sup nasal cavity - olfactory epithelium - has bipolar sensory neurons - has dendrites that extend from apical surface into mucus lining - odorant moleecules bind to proteins in mucus which goes to cell membrane of olfactory dendrite that produces a graded membrane potential - axon from vasal through foramen in cribriform plate of ethmoid bone into brain, olfactory tract connect to olfactory bulb on ventral surface of frontal lobe - some project to temporal lobe and some to limbic and hypothalamus where smell becomes associated with memory and emotional responses |
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this is the one sensory modality that does not synapse in thalamus before connecting to cerebral cortex |
smell |
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anosmia |
loss of smell - frontal lobe moves and olfactory tract axons sheared - antibiotics by killin olfactory neurons at once - inflammation and allergies |
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audition |
hearing - auricle or pinna - detects sound waves toward auditory canal - canal enters skull through external auditory meatus of temporal bone, at end of auditory canal is tympanic membrane (ear drum) |
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auricle, ear canal, tympanic membrane referred to as |
external ear |
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middle ear |
space spanned by 3 small bones called ossicles (malleus, incus, and stapes) - mallues attached to tympanic membrane - stapes attached to inner ear |
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sound waves transduced into neural signal in |
inner ear |
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middle ear connected to pharynx through |
eustachian tube , helps equilibrate air pressure across tympanic membrane - open when swallowing or yawning |
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The inner ear contains the |
cochlea and vestibule, which are responsible for audition and equilibrium, respectively. - distinct bundles travel together from inner ear to brain stem as vestibulocochlear nerve |
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cochlear region of inner ear |
where sound to neural signals and has spiral ganglia - attached to stapes through oval window |
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central cavity of cochlea |
cochlear duct - has sound transducing neurons |
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A sound wave causes the |
tympanic membrane to vibrate. This vibration is amplified as it moves across the malleus, incus, and stapes. The amplified vibration is picked up by the oval window causing pressure waves in the fluid of the scala vestibuli and scala tympani. The complexity of the pressure waves is determined by the changes in amplitude and frequency of the sound waves entering the ear |
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organs of corti |
transduce wave movtion of 2 scala into neural signals - lie on top of basilar membrane (between corti and scala tympani |
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higher frequency waves move region of basilar membrane that is close to |
base of cochlea |
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lower frequency waves move rgion of basilar membrane that is near |
tip of cochlea |
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The organ of Corti, containing the |
mechanoreceptor hair cells, is adjacent to the scala tympani, where it sits atop the basilar membrane |
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when pressure waves from scala move the basilar membrane |
tecotrial membrane slides across the sterocilia - when bend toward tallest member tensioni nprotein opens ion channels, depolarizes the hair cell membrane, triggereing nerve impulses - when sterocilia bend toward shortest member, tesnion slackens and ion channels close - when no sound small amount of tension still exists keeping membrane potential slightly depolarized |
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The hair cell is a mechanoreceptor with an array of stereocilia emerging from its apical surface. The stereocilia are tethered together by proteins that open ion channels when the array is bent toward the tallest member of their array, and closed when the array is bent toward the shortest member of their arr |
ya |
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cochlea encodes auditory stimuli for frequencies between |
20- 20k hz - cycles per second -20 hz is in tip - 20khz are base of cochlea close to round and oval windows |
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The standing sound wave generated in the cochlea by the movement of the oval window deflects the basilar membrane on the basis of the frequency of sound. Therefore, hair cells at the base of the cochlea are activated only by high frequencies, whereas those at the apex of the cochlea are activated only by low frequencies |
ya |
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equilibrium (balance) |
inner ear - in vestibule of inner ear - head position sensed by utricle and saccule - head movement sensed by semiceircular canals - neural signals in vestibular ganglion are transmitted through vestibulocochlear nerve to brain stem and cerebellum - stereocilia extend into viscous gel called otolithic membrane - on top of otolithic membrane is calcium carbonate crystals called otoliths |
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utricle and saccule are composed of |
macula tissue - surrounded by support cells |
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gravity detected by |
otolithic membrane sliding over macula in diretion of gravity - this bends the stercilia, causing some hair cells to depolarize as other hyperpolarize |
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The maculae are specialized for sensing linear acceleration, such as when gravity acts on the tilting head, or if the head starts moving in a straight line. The difference in inertia between the hair cell stereocilia and the otolithic membrane in which they are embedded leads to a shearing force that causes the stereocilia to bend in the direction of that linear acceleration |
ya |
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ampulla |
has hair cells that respond to rotational movement |
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cupula |
membrane that attaches to top of ampula - as head rotates cupula bends in opposite direction of rotation |
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Rotational movement of the head is encoded by the hair cells in the base of the semicircular canals. As one of the canals moves in an arc with the head, the internal fluid moves in the opposite direction, causing the cupula and stereocilia to bend. The movement of two canals within a plane results in information about the direction in which the head is moving, and activation of all six canals can give a very precise indication of head movement in three dimensions. |
ya |
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capsaiin |
active molecule in hot peppers - bind to ion transmembrane in nociceptors sensitive to temps above 37 c - topical analgesic (icyhot) |
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Stretching of the skin is transduced by stretch receptors known as |
bulbous corpuscles. Bulbous corpuscles are also known as Ruffini corpuscles, or type II cutaneous mechanoreceptors |
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stretch receeptors |
muscle spindles |
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transduce stretch levels of tendons |
golgi tendon organs |
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free nerve endings in |
dermis, cornea, tongue, joint capsules, visceral organs - stimuli = pain, temp, mechanical deforamion |
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mechanoreceptors |
- merkels discs - epidermal, mucosal membranes - low freq vibration 5-15hz |
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bulbous corpuscle |
- ruffinis corpuscle - dermis, joint capsules - stretch |
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tactile corpuscle |
- meissners corpuscle - papillary dermis, fingertips and lips - light touch, vib below 50 hz |
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lemellated corpuscle |
- pacinian corpuscle - deep dermis, subcutaneous tissue - deep pressure, high freq 250 hz |
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tendon stretch organ |
- golgi tendon organ - in line with tendons - stretch of tendons |
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muscles of orbit |
superior rectus, medial rectus, inferior rectus, lateral rectus, superior oblique, trochlea, levator palpabrae superioris |
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lateral rectus |
aabduction of eye - innervated by abducens nerve |
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superior oblique |
innervated by trochlear nerve |
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all ocular muscles innervated by |
oculomotor nerve |
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3 layers of eye |
outermost is fibrous tunic = sclera and cornea middle layer = vascular tunic, composed of choroid(highly vascularized, post to ciliary body , ciliary body(connected to lens by zonule fibers), and iris (muscle that opens or closes pupil) innermost layer = neural tunic or retina (photoreception center) |
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anterior cavity of eye |
between cornea and lens - includes iris and ciliary body - filled with aqueous humor |
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posterior cavity of eye |
retina filled with vitreous humor |
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bipolar cells in retina connect photoreceptor to |
retinal ganglion cell in inner synaptic layer - amacrine cells process - retinal ganglion cells collect at optic discs and leave as optic nerve |
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center of retina has small indentation known as |
fovea |
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visual acuity greatest at |
fovea |
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rod shaped photoreceptors |
rod photoreceptors - membrane bound discs contain rhodopsin |
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cone photoreceptor |
3 ospins(rgb) in infoldings of cell membrane |
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single unit of light |
photon |
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visible light |
electromagnetic radiation with wl between 380-720 nm - longer than 720 nm are infrared - shorter than 380 nm are uv - 380 is blue - 720 is dark red |
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opsins |
transmembrane proteins that have cofactor retinal - hydrocarbon molecule like vit a - |
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photoisomerization |
photons cause db carbons from cis to trans |
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11-cis-retinal ad opsin form |
rhodopsin - 11-cis-retinal = before photon interacts - all trans retinal - altered through photoisomerization |
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rhodopsin in rods sensitive to light at wl of |
498nm - peak at 564 red, 534 green, 420 blue - more senstive than cones (low light) |
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topographical arrangement |
location of sensory receptor relates to location of axon in nerve |
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contralateral |
right side of body is conneted to left side of brain and left side of body is connected to right side of brain - spinal nerve systems that connect to brain |
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cranial nerve systems are mostly |
ipsilateral - right side of brain to right side of body |
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cranial nerves containing only sensory axons |
olfactory, optic, vestibulocochlear nerves |
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cranial nerves with both sensory and motor axons |
trigeminal, facial, glossopharyngeal, vagus nerves |
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The general senses of somatosensation for the face travel through the |
trigeminal system |
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cns somatic processes |
spinal cord brain stem, diencephalon, cerebral cortex, subcortical strucutres |
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sensory path that carries peripheral sensations to brain |
ascending path or tract |
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somatosensory stimulit from below neck along |
spinal cord |
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somatosensory stimuli from head and neck travel throug |
cranial nerves - trigeminal system |
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2 major paths of bringing sensory info to brain |
- dorsal column system - spinothalamic tract |
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dorsal column system |
- begins with axon of dorsal root ganglion neuron entering dorsal root and joingin dorsal column white matter - column split into 2 tracts : fasciculus gracillis (that has axons from legs and lower body and terminates in nucleus gracilis) and fasciculus cuneatus (that has axons from upper body and arms and terminates in nucleus cuneatus) - terminate in nuclei of medulla - responsible for touch sensations and proprioception - 2nd neurons are contralateral |
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decussates |
crosses midline of medulla - then ascend brain stem as medial lemniscus (these terminate in thalamus) |
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spinothalamic tract |
- begins with neurons in dorsal root ganglion then to horn - axons from 2nd neurons decussate within spinal cord and ascend to brain and enter thalamus - synapses in postcetral gyrus of cerebral cortex - responsible for pain and temp sensations - 2nd neurons are contralateral |
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alkaloid substance |
usually from a plant source, that is chemically basic with respect to pH and will stimulate bitter receptors |
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amacrine cell |
type of cell in the retina that connects to the bipolar cells near the outer synaptic layer and provides the basis for early image processing within the retina |
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ampulla |
in the ear, the structure at the base of a semicircular canal that contains the hair cells and cupula for transduction of rotational movement of the head |
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anosmia |
loss of the sense of smell; usually the result of physical disruption of the first cranial nerve |
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anterior corticospinal tract |
division of the corticospinal pathway that travels through the ventral (anterior) column of the spinal cord and controls axial musculature through the medial motor neurons in the ventral (anterior) horn |
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aqueous humor |
watery fluid that fills the anterior chamber containing the cornea, iris, ciliary body, and lens of the eye |
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ascending pathway |
fiber structure that relays sensory information from the periphery through the spinal cord and brain stem to other structures of the brain |
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association area |
region of cortex connected to a primary sensory cortical area that further processes the information to generate more complex sensory perceptions |
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audition |
sense of hearing auricle fleshy external structure of the ear |
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basilar membrane |
in the ear, the floor of the cochlear duct on which the organ of Corti sits |
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Betz cells |
output cells of the primary motor cortex that cause musculature to move through synapses on cranial and spinal motor neurons |
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binocular depth cues |
indications of the distance of visual stimuli on the basis of slight differences in the images projected onto either retina |
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bipolar cell |
cell type in the retina that connects the photoreceptors to the RGCs |
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Broca’s area |
region of the frontal lobe associated with the motor commands necessary for speech production |
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capsaicin |
molecule that activates nociceptors by interacting with a temperature-sensitive ion channel and is the basis for “hot” sensations in spicy food |
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cerebral peduncles |
segments of the descending motor pathway that make up the white matter of the ventral midbrain |
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cervical enlargement |
region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of and finer control of muscles of the upper limb |
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chemoreceptor |
sensory receptor cell that is sensitive to chemical stimuli, such as in taste, smell, or pain |
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chief sensory nucleus |
component of the trigeminal nuclei that is found in the pons choroid highly vascular tissue in the wall of the eye that supplies the outer retina with blood |
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ciliary body |
smooth muscle structure on the interior surface of the iris that controls the shape of the lens through the zonule fibers |
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circadian rhythm |
internal perception of the daily cycle of light and dark based on retinal activity related to sunlight |
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cochlea |
auditory portion of the inner ear containing structures to transduce sound stimuli |
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cochlear duct |
space within the auditory portion of the inner ear that contains the organ of Corti and is adjacent to the scala tympani and scala vestibuli on either side |
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cone photoreceptor |
one of the two types of retinal receptor cell that is specialized for color vision through the use of three photopigments distributed through three separate populations of cells |
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contralateral |
word meaning “on the opposite side,” as in axons that cross the midline in a fiber tract |
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cornea |
fibrous covering of the anterior region of the eye that is transparent so that light can pass through it |
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corneal reflex |
protective response to stimulation of the cornea causing contraction of the orbicularis oculi muscle resulting in blinking of the eye |
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corticobulbar tract |
connection between the cortex and the brain stem responsible for generating movement |
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corticospinal tract |
connection between the cortex and the spinal cord responsible for generating movement |
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cupula |
specialized structure within the base of a semicircular canal that bends the stereo cilia of hair cells when the head rotates by way of the relative movement of the enclosed fluid |
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decussate |
to cross the midline, as in fibers that project from one side of the body to the other |
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dorsal column system |
ascending tract of the spinal cord associated with fine touch and proprioceptive sensations |
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dorsal stream |
connections between cortical areas from the occipital to parietal lobes that are responsible for the perception of visual motion and guiding movement of the body in relation to that motion |
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encapsulated ending |
configuration of a sensory receptor neuron with dendrites surrounded by specialized structures to aid in transduction of a particular type of sensation, such as the lamellated corpuscles in the deep dermis and subcutaneous tissue |
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equilibrium |
sense of balance that includes sensations of position and movement of the head |
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executive functions |
cognitive processes of the prefrontal cortex that lead to directing goal-directed behavior, which is a precursor to executing motor commands |
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external ear |
structures on the lateral surface of the head, including the auricle and the ear canal back to the tympanic membrane |
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exteroceptor |
sensory receptor that is positioned to interpret stimuli from the external environment, such as photoreceptors in the eye or somatosensory receptors in the skin |
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extraocular muscle |
one of six muscles originating out of the bones of the orbit and inserting into the surface of the eye which are responsible for moving the eye |
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extrapyramidal system |
pathways between the brain and spinal cord that are separate from the corticospinal tract and are responsible for modulating the movements generated through that primary pathway |
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fasciculus cuneatus |
lateral division of the dorsal column system composed of fibers from sensory neurons in the upper body |
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fasciculus gracilis |
medial division of the dorsal column system composed of fibers from sensory neurons in the lower body |
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fibrous tunic |
outer layer of the eye primarily composed of connective tissue known as the sclera and cornea |
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fovea |
exact center of the retina at which visual stimuli are focused for maximal acuity, where the retina is thinnest, at which there is nothing but photoreceptors |
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free nerve ending |
configuration of a sensory receptor neuron with dendrites in the connective tissue of the organ, such as in the dermis of the skin, that are most often sensitive to chemical, thermal, and mechanical stimuli |
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frontal eye fields |
area of the prefrontal cortex responsible for moving the eyes to attend to visual stimuli |
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general sense |
any sensory system that is distributed throughout the body and incorporated into organs of multiple other systems, such as the walls of the digestive organs or the skin gustation sense of taste gustatory receptor cells sensory cells in the taste bud that transduce the chemical stimuli of gustation hair cells |
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mechanoreceptor |
cells found in the inner ear that transduce stimuli for the senses of hearing and balance |
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incus (also, anvil) |
ossicle of the middle ear that connects the malleus to the stapes |
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inferior colliculus |
last structure in the auditory brainstem pathway that projects to the thalamus and superior colliculus |
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inferior oblique |
extraocular muscle responsible for lateral rotation of the eye |
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inferior rectus |
extraocular muscle responsible for looking down |
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inner ear |
structure within the temporal bone that contains the sensory apparati of hearing and balance |
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inner segment in the eye, |
the section of a photoreceptor that contains the nucleus and other major organelles for normal cellular functions |
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inner synaptic layer |
layer in the retina where bipolar cells connect to RGCs |
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interaural intensity difference |
cue used to aid sound localization in the horizontal plane that compares the relative loudness of sounds at the two ears, because the ear closer to the sound source will hear a slightly more intense sound interaural time difference cue used to help with sound localization in the horizontal plane that compares the relative time of arrival of sounds at the two ears, because the ear closer to the sound source will receive the stimulus microseconds before the other ear |
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internal capsule |
segment of the descending motor pathway that passes between the caudate nucleus and the putamen |
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interoceptor |
sensory receptor that is positioned to interpret stimuli from internal organs, such as stretch receptors in the wall of blood vessels |
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ipsilateral |
word meaning on the same side, as in axons that do not cross the midline in a fiber tract |
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iris |
colored portion of the anterior eye that surrounds the pupil |
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kinesthesia |
sense of body movement based on sensations in skeletal muscles, tendons, joints, and the skin lacrimal duct duct in the medial corner of the orbit that drains tears into the nasal cavity |
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lacrimal gland |
gland lateral to the orbit that produces tears to wash across the surface of the eye |
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lateral corticospinal tract |
division of the corticospinal pathway that travels through the lateral column of the spinal cord and controls appendicular musculature through the lateral motor neurons in the ventral (anterior) horn |
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lateral geniculate nucleus |
thalamic target of the RGCs that projects to the visual cortex |
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lateral rectus |
extraocular muscle responsible for abduction of the eye |
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lens |
component of the eye that focuses light on the retina |
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levator palpebrae superioris |
muscle that causes elevation of the upper eyelid, controlled by fibers in the oculomotor nerve |
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lumbar enlargement |
region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of muscles of the lower limb |
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macula |
enlargement at the base of a semicircular canal at which transduction of equilibrium stimuli takes place within the ampulla |
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malleus (also, hammer) |
ossicle that is directly attached to the tympanic membrane |
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mechanoreceptor |
receptor cell that transduces mechanical stimuli into an electrochemical signal |
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medial geniculate nucleus |
thalamic target of the auditory brain stem that projects to the auditory cortex |
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medial lemniscus |
fiber tract of the dorsal column system that extends from the nuclei gracilis and cuneatus to the thalamus, and decussates |
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medial rectus |
extraocular muscle responsible for adduction of the eye |
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mesencephalic nucleus |
component of the trigeminal nuclei that is found in the midbrain middle ear space within the temporal bone between the ear canal and bony labyrinth where the ossicles amplify sound waves from the tympanic membrane to the oval window |
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multimodal integration area |
region of the cerebral cortex in which information from more than one sensory modality is processed to arrive at higher level cortical functions such as memory, learning, or cognition |
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neural tunic |
layer of the eye that contains nervous tissue, namely the retina nociceptor receptor cell that senses pain stimuli |
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nucleus cuneatus |
medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the upper body and arms |
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nucleus gracilis |
medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the lower body and legs |
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odorant molecules |
volatile chemicals that bind to receptor proteins in olfactory neurons to stimulate the sense of smell |
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olfaction |
sense of smell |
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olfactory bulb |
central target of the first cranial nerve; located on the ventral surface of the frontal lobe in the cerebrum olfactory epithelium region of the nasal epithelium where olfactory neurons are located |
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olfactory sensory neuron |
receptor cell of the olfactory system, sensitive to the chemical stimuli of smell, the axons of which compose the first cranial nerve |
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optic chiasm |
decussation point in the visual system at which medial retina fibers cross to the other side of the brain |
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opsin |
protein that contains the photosensitive cofactor retinal for phototransduction |
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optic disc |
spot on the retina at which RGC axons leave the eye and blood vessels of the inner retina pass optic nerve second cranial nerve, which is responsible visual sensation optic tract name for the fiber structure containing axons from the retina posterior to the optic chiasm representing their CNS location |
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organ of Corti |
structure in the cochlea in which hair cells transduce movements from sound waves into electrochemical signals |
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osmoreceptor |
receptor cell that senses differences in the concentrations of bodily fluids on the basis of osmotic pressure - fluid balance |
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ossicles |
three small bones in the middle ear |
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layer of calcium carbonate crystals located on top of the otolithic membrane |
otolith |
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gelatinous substance in the utricle and saccule of the inner ear that contains calcium carbonate crystals and into which the stereocilia of hair cells are embedded |
otolithic membrane |
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in the eye, the section of a photoreceptor that contains opsin molecules that transduce light stimuli |
outer segment |
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layer in the retina at which photoreceptors connect to bipolar cells |
outer synaptic layer |
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membrane at the base of the cochlea where the stapes attaches, marking the beginning of the scala vestibuli |
oval window |
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membrane attached to the inner surface of the eyelids that covers the anterior surface of the cornea |
palpebral conjunctiva |
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papilla |
for gustation, a bump-like projection on the surface of the tongue that contains taste buds |
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chemical change in the retinal molecule that alters the bonding so that it switches from the11-cis- retinal isomer to the all-trans-retinal isomer |
photoisomerization |
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photoreceptor |
receptor cell specialized to respond to light stimuli |
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premotor cortex |
cortical area anterior to the primary motor cortex that is responsible for planning movements |
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region of the cerebral cortex that initially receives sensory input from an ascending pathway from the thalamus and begins the processing that will result in conscious perception of that modality |
primary sensory cortex |
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sense of position and movement of the body |
proprioception |
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receptor cell that senses changes in the position and kinesthetic aspects of the body |
proprioceptor |
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open hole at the center of the iris that light passes through into the eye |
pupil |
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location at which corticospinal tract fibers cross the midline and segregate into the anterior and lateral divisions of the pathway |
pyramidal decussation |
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pyramids |
segment of the descending motor pathway that travels in the anterior position of the medulla |
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receptor cell |
cell that transduces environmental stimuli into neural signals |
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red nucleus |
midbrain nucleus that sends corrective commands to the spinal cord along the rubrospinal tract, based on disparity between an original command and the sensory feedback from movement |
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extrapyramidal connections between the brain stem and spinal cord that modulate movement, contribute to posture, and regulate muscle tone |
reticulospinal tract |
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nervous tissue of the eye at which phototransduction takes place |
retina |
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cofactor in an opsin molecule that undergoes a biochemical change when struck by a photon (pronounced with a stress on the last syllable) |
retinal |
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neuron of the retina that projects along the second cranial nerve |
retinal ganglion cell (RGC) |
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photopigment molecule found in the rod photoreceptors |
rhodopsin |
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one of the two types of retinal receptor cell that is specialized for low-light vision |
rod photoreceptor |
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membrane that marks the end of the scala tympani |
round window |
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descending motor control pathway, originating in the red nucleus, that mediates control of the limbs on the basis of cerebellar processing |
rubrospinal tract |
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structure of the inner ear responsible for transducing linear acceleration in the vertical plane |
saccule |
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portion of the cochlea that extends from the apex to the round window |
scala tympani |
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portion of the cochlea that extends from the oval window to the apex |
scala vestibuli |
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sclera |
white of the eye |
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structures within the inner ear responsible for transducing rotational movement information |
semicircular canals |
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topographic representation of the body within the somatosensory cortex demonstrating the correspondence between neurons processing stimuli and sensitivity |
sensory homunculus |
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sensory modality |
a particular system for interpreting and perceiving environmental stimuli by the nervous system |
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medullar nucleus that receives taste information from the facial and glossopharyngeal nerves |
solitary nucleus |
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general sense associated with modalities lumped together as touch special sense any sensory system associated with a specific organ structure, namely smell, taste, sight, hearing, and balance |
somatosensation |
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component of the trigeminal nuclei that is found in the medulla spinothalamic tract ascending tract of the spinal cord associated with pain and temperature sensations |
spinal trigeminal nucleus |
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location of neuronal cell bodies that transmit auditory information along the eighth cranial nerve stapes (also, stirrup) ossicle of the middle ear that is attached to the inner ear |
spiral ganglion |
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stereocilia |
array of apical membrane extensions in a hair cell that transduce movements when they are bent |
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response to activation of the muscle spindle stretch receptor that causes contraction of the muscle to maintain a constant length |
stretch reflex |
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submodality |
specific sense within a broader major sense such as sweet as a part of the sense of taste, or color as a part of vision |
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superior colliculus |
structure in the midbrain that combines visual, auditory, and somatosensory input to coordinate spatial and topographic representations of the three sensory systems |
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extraocular muscle responsible for medial rotation of the eye |
superior oblique |
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muscle responsible for looking up |
superior rectus extraocular |
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cortical area anterior to the primary motor cortex that is responsible for planning movements |
supplemental motor area |
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hypothalamic target of the retina that helps to establish the circadian rhythm of the body on the basis of the presence or absence of daylight |
suprachiasmatic nucleus |
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component of the organ of Corti that lays over the hair cells, into which the stereocilia are embedded |
tectorial membrane |
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extrapyramidal connections between the superior colliculus and spinal cord |
tectospinal tract |
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transduction |
process of changing an environmental stimulus into the electrochemical signals of the nervous system |
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cartilaginous structure that acts like a pulley for the superior oblique muscle |
trochlea |
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ear drum |
tympanic membrane |
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umami |
taste submodality for sensitivity to the concentration of amino acids; also called the savory sense |
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structure of the inner ear responsible for transducing linear acceleration in the horizontal plane |
utricle |
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middle layer of the eye primarily composed of connective tissue with a rich blood supply |
vascular tunic |
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nucleus in the thalamus that is the target of gustatory sensations and projects to the cerebral cortex |
ventral posterior nucleus |
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connections between cortical areas from the occipital lobe to the temporal lobe that are responsible for identification of visual stimuli |
ventral stream |
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location of neuronal cell bodies that transmit equilibrium information along the eighth cranial nerve |
vestibular ganglion |
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targets of the vestibular component of the eighth cranial nerve vestibule in the ear, the portion of the inner ear responsible for the sense of equilibrium |
vestibular nuclei |
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reflex based on connections between the vestibular system and the cranial nerves of eye movements that ensures images are stabilized on the retina as the head and body move |
vestibulo-ocular reflex (VOR) |
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extrapyramidal connections between the vestibular nuclei in the brain stem and spinal cord that modulate movement and contribute to balance on the basis of the sense of equilibrium |
vestibulospinal tract |
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sense associated with the internal organs |
visceral sense |
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visual acuity |
property of vision related to the sharpness of focus, which varies in relation to retinal position |
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viscous fluid that fills the posterior chamber of the eye working memory function of the prefrontal cortex to maintain a representation of information that is not in the immediate environment |
vitreous humor |
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fibrous connections between the ciliary body and the lens |
zonule fibers |
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senses are |
- olfaction (smell) - gustation ( taste) - somatosensation (skin and body sensations) (G) ` touch, tactile, pressure, vibration, temp, pain - audition - equilibrium - vision |
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sensory stimuli cells structrual classifications |
- free nerve endings - encapsulated endings - specialized receptor cells - interoceptor - exteroceptor - proprioceptor |
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chemoreceptors |
respond to chemical stimuli and are basis for olfaction and gustation |
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mechanoreceptors |
mechanical stimuli - basis for somatosensation - basis of audition and equilibrium in inner ear |
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in diencephalon sensory pathways reach |
thalamus - necessary for all sensory systems (except olfactory bc it is directly connected to frontal and temporal lobes) to reach cerebral cortex |
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dorsal column system |
- major tract in spinal cord - originates form sensory neurons in dorsal root ganglia - touch and proprioception - decussion in medulla |
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spinthalamic tract |
- major tract in spinal cord - originates form sensory neurons in dorsal root ganglia - pain and temp - decussation at spinal cord where enters |
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vestibular system enters brain stema nd |
influences activity in cerebellum, spinal cord, and cerevral cortex |
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auditory pathway passes through |
multiple nuclei in brain stem - sound localization |
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visual cortical areas perception along 2 streams |
- ventral and dorsal - ventral visual = connect structuresin temporal lobe that important for long term memory formation - dorsal visual = somatosensory cortex in parietal lobe - together influence activity in frontal love to generate movements of body |
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motor components of somatic nervous system begin with |
frontal lobe - prefrontal cortex responsible for higher functionslike memory |
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integrative and associate funciton of prefrontal lobe feed into |
secondary motor areas, help plan movements |
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premotor cortex and supplemental motor area feed into |
primary motor cortex and intitiates movements |
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large betz cells |
project through corticobulbar and corticospinal tracts to synapse on lower motor neurons in brain stem and ventral horn of the spinal cord - generate movement of skeletal muscles |
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extrapyramidal system |
projections from brain stem that influence movement - balance and posture - muscle tone |
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superior colliculus and red nucleus |
in midbrain have tracts projecting to spinal cord in - extrapyramidal system |
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vestibular nuclei in |
medullar - have tracts projecting to spinal cord in extrapyramidal system |
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reticular formation |
thorughout brain stem - have tracts projecting to spinal cord in extrapyramidal system |
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descending input from secondary motor cortices, basal nuclei, and cerebellum connect to the origins of extrapyramidial tracts |
ya |
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motor pathways project to spinal cord to synapse with |
motor neurons in ventral horn of spinal cord |
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lower motor neurons are cells that connect to |
skeletal muscle and cause contractions - these neurons project through spinal nerves to connect to muscles at neruomuscular juncitons |
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one motor neuron connects to |
multiple muscle fibers within a target muscle |
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number of fibers innervated by single motor neuron |
varies on precision necessary for muscle and necessary force for motor unit - more precise = more motor neurons |
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simplest circuits within somatic nervous system |
reflexes |
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withdrawal reflex only requires |
sensory fiber that enters spinal cord and motor neuron that projects to muscle |
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antagonist and postural muscles can be coordinated with the withdrawal making connections more complex |
ya |
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simple, single neuronal connection is basis of |
somatic reflexes |
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corneal reflex is contraction of |
orbicularis oculi muscle to blink eyelid when something touches the surface of the eye |
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stretch reflexes maintain a constant length of muscles by |
causing a contraction of a muscle to compensate for a stretch that can be sensed by a specialized receptor called a muscle spindle |
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12. What type of receptor cell is responsible for transducing pain stimuli? a. mechanoreceptor b. nociceptor c. osmoreceptor d. photoreceptor |
b. nociceptor |
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13. Which of these cranial nerves is part of the gustatory system? a. olfactory b. trochlear c. trigeminal d. facial |
d. facial |
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14. Which submodality of taste is sensitive to the pH of saliva? a. umami b. sour c. bitter d. sweet |
b. sour |
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15. Axons from which neuron in the retina make up the optic nerve? a. amacrine cells b. photoreceptors c. bipolar cells d. retinal ganglion cells |
d. retinal ganglion cells |
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16. What type of receptor cell is involved in the sensations of sound and balance? a. photoreceptor b. chemoreceptor c. mechanoreceptor d. nociceptor |
c. mechanoreceptor |
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17. Which of these sensory modalities does not pass through the ventral posterior thalamus? a. gustatory b. proprioception c. audition d. nociception |
c. audition |
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18. Which nucleus in the medulla is connected to the inferior colliculus? a. solitary nucleus b. vestibular nucleus c. chief sensory nucleus d. cochlear nucleus |
d. cochlear nucleus |
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19. Visual stimuli in the upper-left visual field will be processed in what region of the primary visual cortex? a. inferior right b. inferior left c. superior right d. superior left |
a. inferior right |
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20. Which location on the body has the largest region of somatosensory cortex representing it, according to the sensory homunculus? a. lips b. thigh c. elbow d. neck |
a. lips |
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21. Which of the following is a direct target of the vestibular ganglion? a. superior colliculus b. cerebellum c. thalamus d. optic chiasm |
b. cerebellum |
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22. Which region of the frontal lobe is responsible for initiating movement by directly connecting to cranial and spinal motor neurons? a. prefrontal cortex b. supplemental motor area c. premotor cortex d. primary motor cortex |
d. primary motor cortex |
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23. Which extrapyramidal tract incorporates equilibrium sensations with motor commands to aid in posture and movement? a. tectospinal tract b. vestibulospinal tract c. reticulospinal tract d. corticospinal tract |
b. vestibulospinal tract |
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24. Which region of gray matter in the spinal cord contains motor neurons that innervate skeletal muscles? a. ventral horn b. dorsal horn c. lateral horn d. lateral column |
a. ventral horn |
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25. What type of reflex can protect the foot when a painful stimulus is sensed? a. stretch reflex b. gag reflex c. withdrawal reflex d. corneal reflex |
c. withdrawal reflex |
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26. What is the name for the topographical representation of the sensory input to the somatosensory cortex? a. homunculus b. homo sapiens c. postcentral gyrus d. primary cortex |
a. homunculus |
