Midterm 2 Flashcards
What does the anterolateral system transmit?
nociceptive, itch, thermal, and crude touch info
What is the sequence of neurons in the anterolateral system?
1st order neuron in DRG, 2nd order neuron in dorsal horn, 3rd order neuron in thalamus
also could include interneurons
What is the direct pathway of anterlateral system?
spinothalamic tract/neospinothalamic
the 2nd order neuron in this case synapses w/contralateral thalamus and sends collaterals to reticular formation
What is the indirect pathway of anterolateral system?
spinoreticular tract
indirect b/c 2nd order neuron goes to retucular formation before sending collaterals to thalamus
What are the differnt tracts in anterolateral system? (6)
spinothalamic, spinoreticular, spinomesencephalic, spinotectal, spinohypothalmic, spinobulbar
What is Brown-Sequard syndrome? (cause)
incomplete injury to spinal cord (hemisected), ascending and descending tracts on that side are damaged
What are the symptoms of Brown-Sequard syndrome?
weakness or paralysis, proprioceptive deficits, two point discrimination, fine touch, astereognosis on the side of the body ipsilateral to the lesion, and loss of pain and temperature sensation on the contralateral side
What is astereognosis?
unable to identify shape of known object when eyes are closed and touching it
What is congential insensitivity to pain (CIP)?
rare (1 in 125 million), lack of pain sensitivity, likely due to mutations that stop nociceptors in the dorsal root ganglion from sending signals
What are contact receptors?
type of exteroreceptor
transmit tactile, pressure, pain, or thermal stimuli (requires touching)
What does the dorsal column-medial lemniscal system (DCMLS) relay?
fine tactile sense, flutter-vibratory sense, proprioception
What is dorsolateral fasiculus?
fibers split into direct and indirect pathways of ALS, made up of thinly myelinated and unmyelinated axons
aka tract of lissauer
What are some examples of encapsulated mechanoreceptors?
meissner’s corpuscles, pacinian corpuscles, ruffini’s organs
What determines if mechanoreceptors is encapsulated or nonencapsulated?
depends on whetehr a structural device encloses it peripheral nerve ending
What are examples of nonencapsulated mechanoreceptors?
free nerve endings, merkel’s tactile discs, peritrichial nerve endings
What are exteroceptors?
close to body surface and detect sensory info from environment
sensitive to touch, pressure, temperatrue, pain, and flutter vvibration
What are the two types of exteroceptors?
teloreceptors and contact receptors
What is the fasciculus gracilis?
tract in the DCMLS, transmits info from the mid-thoracic level and below, including the lower limbs
What is the fasciculus cuneatus?
transmit the info from the upper extremities (sparing the head
tract in DCMLS
What do free nerve endings respond to?
touch, pressure
What does the General Somatic Afferent system transmit?
SENSORY info like touch, pressure, flutter-vibration, pain, temp, itch, stretch, position from SOMATIC structures
What does the General Visceral Afferent system transmit?
SENSORY info like touch, pressure, flutter-vibration, pain, temp, itch, stretch, position from VISCERAL structures
What are interoreceptors?
detect sensory info concerning body’s internal environment
Blood pressure, pH, oxygenation, osmolarity
What do mechanoceptors detect?
touch, pressure, two point discrimination, vibration, stretching, hair movement
What are meissner’s corpuscles? What do they detect?
Peripheral terminal of Aβ (group II), wrapped by capsule of Schwann cells and connective tissue
two point discrimintive (fine) touch
Where are meissner’s corpuscles located?
papillae of dermis of hairless skin
What are free nerve endings associated with?
Aδ, C fibers
Where are merkel’s tactile discs located?
basal epidermis
What are merkel’s tactile discs associated with?
Aβ (group II) myelinated fibers
What do merkel’s discs detect?
superficial pressure, discrimintive touch
What does the neospinothalamic tract transmit?
fast, well-localized and precise nociceptive input
What does the paleospinothalamic tract transmit?
dull, slow and poorly localized nociceptive input
What are the four types of nociceptors?
Mechanosensitive, temperature sensitive, polymodal, pruriceptors
What are mechanosensittive nociceptors?
Aδ (III) fibres, non-encapsulated branching free nerve endings
sensitive to intense mechanical sitmuli or injury to tissues
What are temperature sensitive nociceptors?
Aδ (III) and C (IV) fibres, non-encapsulated branching free nerve endings
sensititve to heat/cold
What are polymodal nociceptors?
C (IV) fibres, non-encapsulated branching free nerve endings responding to a mixture of things (mechanical, temperature, chemical)
What are pruriceptors?
C (IV) fibres, non-encapsulated branching free nerve endings
Sensitive to histamine (itch)
What is the spinomesencephalic pathway?
part of ALS
Mostly terminate in periaqueductal gray matter and midbrain raphe nuclei
Some terminate in parabrachial nucleus of midbrain
Project to amygdala
What is spinotectal fibers?
Mostly terminates in deep layers of superior colliculus/pretectum
Automatic orienting of body/head/eyes towards pain
What is spinohypothalamic fibers?
Terminates in hypothalamus
Autonomic, reflex responses to pain
What are spinoolivary fibers?
Terminate in inferior olivary nucleus of medulla
Proprioceptive input from cutaneous receptors, muscle spindles, GTOs
Third-order neurons project to cerebellum
included in spinobulbar
What are pacinian corpuscles?
Largest mechanoreceptors
Aβ-fiber terminals encapsulated by layers of modified fibroblasts in connective tissue capsule, Rapid adaptation
found in deep layers on skin and visceral structures
What stimulates pacinian corpuscles?
touch, pressure, vibration, proprioception
What are peritrichial nerve endings?
Aβ fibers, myelinated
Wrapped around the base of hair follicles
Stimulated when the hair is bent
Where is the primary somatosensory cortex located? (SI)
postcentral gyrus of parietal lobe
Where does the primary somatosensory cortex send projections?
to secondary somatosensory cortex
What are proprioceptors?
Static position sense, movement (kinesthetic) sense
found in muscles, tendons, joints, also vestibular system
What is phasic response type?
aka rapidly adapting receptors
fast adapting
respond to changes in stimulus
What is tonic response type?
aka. slowly adapting receptors
slowly adapting
respond to ongoing stimulus
What is the receptive field?
area covered by a single receptor
What are small receptive fields for?
for high resolution information
found in fingertips etcc
What are large receptive fieldss for?
for low rsolution information
found on back etc
What are the components of the reticular activating system?
reticular formation, diencephalon, intralaminar nuclei of thalamus
What is the function of the RAS?
activates entire nervous system to elicit responses thta will enable you to avoid painful stimuli
What are ruffini end organs?
Unmyelinated peripheral terminals of Aβ myelinated fibers
Important for kinesthesia / proprioception
Slowly adapting
Where are ruffini end organs foudnd?
They intertwine around core of collagen fibers, surrounded by a lamellated cellular capsule
What do ruffini end organs respond to?
Respond to stretching of the collagen bundles in the skin or joint capsules
What is the purpose of selective dorsal rhizotomy?
Selectively sever some rootlets of the dorsal root to reduce spasticity caused by over-active reflexes
What is spasticity?
characterized by increased muscle sitffnes and increased reflexes
Lack of inhibitory signals in the spinal cord due to reduced descending input
What is tabes dorsalis?
late stage consequence of neurosyphilis
slow degeneration of the neural tracts primarily in the dorsal root ganglia of the spinal cord
How to assess tabes dorsalis?
rombergs test
ex. Can you maintain balance for 60 seconds with your eyes closed?
We require at least 2 of these senses to maintain balance:
Lower limb proprioception
Vision
Vestibular
What are teloreceptors?
distant stimuli
lights/sounds
The VPL is extremaly sensitive to?
proprioception and touch
What is anterior paracentral grys?
inner part of the precentral gyrus which extends to the medial surface of cerebral hemisphere. is responsible for controlling the leg region
What is the association ccortex?
part of the cerebral cortex that performs complex cognitive functions
integrates info from diff parts of brain
What are betz cells?
largest cells in cortex, have the largest axons, project to motor neurons
What is the function of cerebellum?
role in timing, speed, direction, and precision of motor activity
What are the 4 premotor cortical areas?
premotor cortex, supplementary motor cortex, frontal eye field, cingulate motor areas
What is corona radiata?
bundle of projection fibers connecting the cortices of the brain with the brainstem via the internal capsule
What is the function of corticonuclear tract?
aka corticobulbar tract
conscious control of muscles involved in facial expression, chewing, swallowing, and speech
Where does corticonuclear tract originate? Where does it go?
the lower part of the primary motor cortex
descend through the internal capsule, targets cranial nerve motor nuclei (doesn’t do eye movements)
What is corticoreticular tract?
Projections of supplementary motor and premotor cortex to nuclei of the reticular formation in the brainstem
What is corticorrubral tract?
comes from sensorimotor tract, projects to red nucleus
What is corticospinal tract?
Excitatory projections (glutamate) from cortical areas descend through internal capsule, Proceed down through the crus cerebri of the midbrain
Projections decussate at the pyramids
WHat is corticotectal tract
Secondary visual cortical areas project to oculomotor accessory nuclei and superior colliculus
What is the crus cerebri?
connects cerebral hemispheres to cerbellum
What does stimulation of the frontal eye field typically cause?
deviation of both eyes toward contralateral side
Each semicircular duct has a dilated segment at the end called?
ampulla
What is the cupula?
the dome shaped glyco-protein membrane of the cristae ampullares
What is the purpose of the cupula?
narrows tube and increases resistance to flow of endolymph
not influenced by gravitational forces
What are the components of the bony labyrinth of the ear?
cochlea, 3 bony semicircular canals, vestibule
What is the space separating the bony from membrane labyrinth filled with?
perilymph
What does yaw, pitch, and roll mean?
yaw is head movement like shaking head no, pitch is nodding yes, roll is moving sideways from shoulder to shoulder
What plane are the lateral semiciruclar canals oriented in?
horizontal yaw plane
What plane are the anterior and posterior semicircular canals oriented in?
half pitch half roll planes
What is vestibule?
continuous with semicircular canals, contains 2 membrane sacs which each contain a elliptical shaped sneosry receptor (macula)
What are the equilibirum components of the membranous labyrinth?
3 semicircular ducts, urticle, and saccule
What contains endolymph?
membranous labyrinth
Where are semicircular ducts located?
contained in their respective semicircular canal
What muslce allows for accomodation?
ciliary muscle
How does lens change when focusing on near objects?
ciliary muscle contracts which allows lens to thicken (accomodated)
WHat are the three parts of convergence accomodation reflex?
- eyes converge on nearby object, done by medial recti muslces and oculomotor nerve
- ciliary msucle contracts relaxing lens
- pupil constricts
What is anopsia?
visual field loss
What is heminopsia?
loss of 1/2 visual field in one or both eyes
What is the binocular zone?
center of visual field that is seen with both eyes
What do bipolar cells do in retina?
transmit signals from the photoreceptors to the ganglion cells
What layers of retina are bipolar cells in?
outer plexiform layer (where they synapse w/receptors), inner nuclear layer (where the bodies are), inner plexiform layer (where they synapse w/ganglion)
What does the calcarine sulcus mark?
primary visual cortex
What is the ciliary muscle?
smooth muscle contained in ciliary body that changes lens shape for accomodation
What are colour columns?
vertical collections of nerves that detect the colour of visual stimuli
What layers of the cortex are colour columns in?
layers II and III
What are the two lenses of the eye?
lens and cornea
What is the corneal blink reflex?
when anything touches the cornea GSA sensations are transmitted to 1st order psuedounipolar neurons to trigmenial nerve, which sends signals to blink
What is the dorsal stream?
where pathway, carries info to determine movement and spatial localization
What stream is magnocellular layer involved in? (M ganglion cells)
where stream
What layers are the magnocellular layers of LGN?
1 and 2
What is the fovea?
dip in retina where there are only cones, highest visual acuity
What is the role of retinal ganglion cells?
collect all the visual information perceived by the eyes and send it to the brain where it will be processed
What is inferior temporal cortex (IT) involved with?
ventral stream, for processing form and colour, storing visual memories
What is acoustic neuromas? What do they cause?
a tumor arising from schwann cells covering vestibulocochlear nerve (CN VIII)
causes deafness in ipsilateral ear and tinnitus/vestibular symptoms
What is the sixth cranial nerve? (CN VI)
abducent nerve (GSE)
What is the function of CN VI? (abducent nerve)
innervates the lateral rectus muscle of eye
“abducts the eye”
What would an abducent nerve lesion cause?
paralysis of alteral rectus muscles, causes horizontal diplopia and medial strabismus
bilateral lesion causes cross eyed
What would a lesion to abducent nucleus cause?
medial strabismus, horizontal diplopia, and ipsilateral gaze paralysis (b/c no longer provides excitory to oculomotor nucleus neurons)
What is bell’s palsy?
weakness on one side of face (ipsilateral)
involves facial nerve (CN VII)
can lead to crocodile tears (crying wile eating)
What is the main function of the associaton loop?
planning of motor activity and determining direction of movement
What projections are part of the closed association loop?
corticostriate fibers from PFC project to caudate nucleus -> medial part of globus pallidus and pars reticula of substantia nigra -> ventral anterior and dorsomedial nuclei of thalamus -> loop back to prefrontal cortex
What projections are part of open association loop?
corticostriate fibers from premotor and posterior parietl motor -> head of caudate nucleus -> medial part of globus pallidus and pars reticula of substantia nigra -> ventral anterior and dorsomedial nuclei of thalamus -> to PFC
What are the two categories of basal nuclei?
dorsal basal nuclei and ventral basal nuclei
What are components of dorsal basal nuclei?
caudate nucleus, putamen, globus pallidus
What are components of ventral basal nuclei?
ventral striatum, ventral pallidum
What is arbor vitae?
cerebellar white matter, so called for its branched, tree-like appearance
What is ataxia?
lack of coordination of movements, timing and precision are impaired causing awkward movements
What are basket cells?
use GABA, receive excitatory synapses from parallel fibers, make inhibitory synapses w/purkinje cells
What cells are in the molecular layer of cerebellum?
basket cells, outer stellate cells, dendrites of prukinje, parallel fibers of granule cells
outer layer
What cells are in purkinje layer of cerebellum?
soma of purkinje cells
middle layer
What cells are in granular layer of cerebellum?
soma of granule cells, golgi (inner stellate) cells, unipolar brush
inner layer
What is the function of the ossicles?
amplify sound waves
What are names of ossicles?
malleus (hammer), stapes (stirrup), incus (anvil)
What is the auricle?
visible outside of ear
alters the frequency spectrum of sound,
channels soundwaves to ear drum
aka pinna
The sense of hearing is mediated by what nerve?
cochlear nerve
part of the vestibulocochlear nerve (CN VIII)
What is the cochlea?
fluid-filled, spiral-shaped cavity found in the inner ear that plays a vital role in the sense of hearing and participates in the process of auditory transduction
What is cochlear ganglion? Other name?
houses the cell bodies of bipolar neurons who synapse with the perihperal ends of hair cells (in ear)
spiral ganglion
What are conjugate eye movements/
when both eyes move toggether in a direction
(horizontal and vertical)
What are optokinetic eye movemennts?
tracking eye movement triggered by motion in visual field
What are 2 types of disconjugate eye movement?
converegent and divergent
What is another name for conjugate horizontal eye movement?
vestibulo-ocular reflex
eyes move to compensate for head movement
(turn head right, eyes turn left)
mediated by abducens nerve (CN VI)
What is involved in conjugate horizontal eye movement?
hair cells in horizontal semicanals detect head movement, sends info to vestibular ganglion, go to abducens and paraabducens nuclei, sent to oculomotor and abducens nerve (CN II and CN VI)
What cranial nerve is ciliary muscle assocaitd with?
oculomotor (CN III)
What is crocodile tear syndrome?
crying while eating
Why does crocodile tears happen?
after lesion to facial nerve, as salivary fibers recover they accidently activate the crying ones
What is the Edinger-Westphal nucleus?
subnucleus of the oculomotor nuclear complex
controls pupil dialtion and lens shape
What are the two groups fibers of the Edingeer-Westphal nucleus?
EWpg (join oculomotor nerve and synpase ciliary ganglion)
EWcp (go to brainstem nuclei, some go to spinal cord)
What is the seventh cranial nerve?
facial nerve (motor + sensory)
What is the function of the facial nerve (CNVII)?
Controls facial expression (SVE), salivation and mucous secretion (GVE), taste in the front 2/3 of the tongue (SVA), and other visceral sensations general sensations (GVA/GSA)
What is the LGN?
relay station of the dorsal thalamis
processes and regualtes visual information and relays to V1
How many layers does LGN have?
6
Layers 1,4,6 of LGN get info from?
nasal half of opposite eye
Layers 2, 3, 5 of LGN get info from?
temporal half of ipsilateral eye
What are the M and P laayers of LGN?
1,2 are M
3,4,5,6 are P
What is macula lutea?
yellow spot on retina, center is fovea
highest visual acuity on retina
Where is the meyer’s loop?
anterior most extension of optic radiations
loop around anterior horn of lateral ventircle
What would a lesion in the meyer’s loop result in?
aka lower division of optic radiation
contralateral upper homonymous quadrantanopsia
(looks like opposite upper 1/4 of visual field of lesion in both eyes)
What is monocular zone?
on both sides of binocular zone, look like parentheses, area seen only by one eye
What are ocular dominance columns?
neurons that receive visual info from ipsilateral or contralateral eye, separate the info from two eyes
found in V1
What is optic ataxia?
impaired hand-eye coordination when interacting with objects in space
What causes optic ataxia?
damage to wwhere pathway
What do orientation columns do?
contain neruons taht detect visual stimyli with comparable spatial orientations
What do P cells detect?
colour and form
(what pathway)
moslty info from cones
What role does the superior colliculus have in eye movements?
midbrain nucleus involved in saccadic eye movement and somatic motor reflexes
The peripheral part of cochlear ganglion form what? What about the central processes?
terminate in basal aspect of hair cells of organ of Corti
form root of cochlear nerve
What is conduction deafness?
involves auditory components of outer and/or middle ear
defect in mechanical transmission of sound
What are some causes of conduction deafness?
wax buildup in external auditory canal, perforation of tympanic membrane, otitis media (inflammation of middle ear), otosclerosis (new bone fixes stapes on oval window)
What is sensorineural deafness?
injury resulting from damage to nerves of ear
What causes sensorineurral deafness?
lesion to cochlea, cochlear nerve, central auditory pathways, presbycusis (degrade of organ Corti)
What is the dorsal cochlear nucleus?
Function?
first relay stations of auditory input
(smaller than ventral)
vertical sound localization
What does the Eustachian tube do?
connects middle ear to nasopharnyx
equalizes atmospheric pressure between middle and outer ear
aka. auditory/pharyngeal tube
What are climbing fibers?
the axons of neurons whose cell bodies are located in inferior olivary nucleus
excitatory, synapse onto 1 purkinje cell many times
Where are the deep cerebellar nuclei found?
in white matter of cerebellym
What is the primary target of purkinje cells?
deep cerebellar nuclei
What are the four deep cerebellar nuclei?
dentate, emboliform, globose, fastigial
What gives input to dentate nucleus?
collaterals of pontocerebellar afferents, purkinje cells
What does dentate nucleus output to?
red nucleus, oculomotor nucleus, reticular formation, cerebellar cortex, inferior olivary nucleus, VL nucleus of thalamus
What is dysarthia?
impaired speech caused by lack of coordination of muslces used to speak
What is dysmetria?
unable to measure the distance between moving body part and target
What are componenets of basal ganglia involved in motor?
caudate nucleus, putamen, globus pallidus, subthalamic nucleus
What is neostriatum referring to?
caudate and putamen
WHat is centromedian nucleus?
1 of the intralaminar nuclei of thalamus
receives input from various ascending pathways about pain sensation
What is the claustrum?
slender layer of grey matter separated from the putamen and insula by the external and extreme capsule respectively
connections to basal ganglia unknown
What makes up the corpus striatum?
caudate, putamen, and globus pallidus
What does the internal capsule do?
carries afferent and efferent fibers to/from cerebral cortex
What number is the internal pyramidal layer?
layer V
What is in the internal pyramidal layer?
cell bodies of pyramidal cells that contribute to the corticospinal and corticonucleur tracts
What happens when we tilt head forward?
eyes tilt back
vice versa for tilt head back
How does conjugate upward eye movement happen?
simultaneous inhibition of the neurons that innervate superior oblique and inferior rectus muslce and stimulation of superior rectus and inferior oblique muslcee
involves trochlear and oculomotor nuclei
What are the receptors in the ampullae of the semicircular ducts called?
cristae ampullares
What are cristae ampullares?
sensory hair cells in semiciruclar ducts
What is medial temporal area?
V5
What are thee visual association cortical areas?
V2, V3. V4. V5
What does V5 process? Where does it project?
spatial details realted to movement
posterior parietal cortex
What does V4 process?
colour and fine details
What is the ventral stream?
what pathway
info relayed from cones to P cells
V1, V2, V4
What is visual agnosia?
see object but unable to identify
What is cranial nerve IX?
glossopharyngeal
What doess the glossopharyngeal nerve control (CN IX)?
Controls swallowing (SVE), some salivation (GVE), taste in the back of the tongue (SVA), and other visceral and general sensations (GVA/GSA), gag relfex
What is cranial nerve XII?
hypoglossal nerve
What does hypoglossal nerve do? (CNXII)
Control of tongue movements (GSE)
What does damage to hypoglossal nerve cause?
tongue deviates to ipsilateral side
What does a unilateral lesion to MLF cause?
internuclear opthalmoplegia
What are symptoms of internuclear opthalmoplegia?
when looking to contralateral side, 1 eye cant move inward, and other eyes looks outward w/nystagmus
What cranial nerve causes jaaw jerk reflex?
trigeminal (CN V)
What causes lateral gaze paralyssi?
damage to abdducens nucleus or PPRF (pontine paramedian reticular formation)
Corticostriate fibers form the ____________ to the basal ganglia?
principal input
Are corticostriate fibers excittatory or inhibiroty?
excitatory
What is CN III?
oculomotor nerve
What does the oculomotor nerve do? (CN III)
innervates superior/medial/inferior rectus muscles and inferior oblique muscles, upper eyelid muscle
Edinger-Westphal nucleus controls lens shape and pupil dilation
What is cranial nerve I (CN I)?
olfactory
What does the olfactory nerve do?
Special visceral afferents connect directly to the olfactory bulb in the brain
What is CN II?
optic nerve
Where does the CN II project to?
diencephalon (lateral geniculate nucleus of the thalamus), superior colliculus, pretectal area, and hypothalamus
What causes ptosis?
damage to CN III (oculomotor)
What is the recurrent laryngeal nerve?
splits off of vagus nerve goes under aortic arch, back up to larynx
What is the external auditory meatus?
canal, funnels sound waves to ear drum
What are frequency columns?
in primary auditory cortex
respond to autidory stimulus of particular frequency
What are the two typess of binaural columns?
summation and suppression columns
What do summation columns respond to?
auditory stimulus that stimulates both ears simultaneously
What do suppression columns respond to?
auditory stimulus that only stimulates 1 ear
What does fastigial nucleus get input from?
collaterals of cerebellar afferents, purkinje cells, vestibulocerebellar fibers, vestibulocochlear nerve
WHat does fastigial nucleus project to?
lateral/medial/inferior vestibular nucleus, VL nucleus of thalamus, cerebellar cortex, reticular formation
The involuntary movements in huntingtons are called?
chorea
What degenerates first in huntingtons?
gabaergic neurons in striatum
What make up whats called the lenticular nucleus?
putamen and globus pallidus
What is the lenticular nucleus also called?
corpus striatum
Where do nigrostriate fibers arise from?
substantia nigra pars compacta
SNpc
What is the nucleus accumbens associated with?
limbic system and processes the emotional aspects of movement
(basal ganglia)
What are the output fibers of globus pallidus?
pallidosubthalamic
pallidonigral
pallidothalamic
Where do centromedian and parafascicular nuclei get their input from?
reticular activating system
avoid pain
What are the output fibers of the striatum?
striatopallidal
striatonigral
What are the input fibers of globus pallidus?
striatopallidal
subthalamopallidal
What is sydenham chorea?
bacterial infection causes antibodies to bidn to striatal neurons
temporary
What is wilson’s disease?
genetic disroder, cant breakdown copper
causes tremors, rigidity, chorea
Which basal nuclei pathway promotes movement initiation?
direct pathway
Which basal nuclei pathway inhibits movement?
indirect pathway
What is SSA?
special somatic affernt
carry info from eyes and ears (vision/hearing)
What is SVA?
special visceral afferent
carry sense of smell and taste
What is SVE
special visceral efferent
innervate skeletal muslce of pharyngeal arch origin
(trigeminal, facial, vagus, glossopharygeal)
What is the function of the sphincter pupillae?
to constrict pupil
What is CN XI?
spinal acceosry nerve
What does the spinal accessory nerve do?
Control of head and shoulder movements (SVE)
What does the trigeminal nerve do?
SVE: Controls chewing , muscles of the vestibular system
GSA: sensation from the scalp, dura, eye, face, sinuses, teeth, front part of tongue
GP: proprioception from muscles of chewing, pressure from teeth, and proprioception from some eye muscles
Only cranial nerve that transmits nociception and thermal sense
What is the CN V?
trigeminal nerrve
What is the CN IV?
trochlear nerve
What does the trochlear nerve do?
GSE: Innervates superior oblique muscle (rotation)
takes long path and is susceptible to damage
What is cranial nerve CN X?
vagus nerve
What does the vagus nerve do?
Controls gland secretion (GVE), phonation (SVE), taste in epiglottis (SVA), many visceral and general sensations including the heart and lungs (GVA/GSA)
What is cranial nerve VIII?
vestibulocochlear
What does the vestibulocochlear nerve do?
Controls hearing (SSA) and equilibrium (vestibular apparatus, SSA)
Each hair cell has?
stereocillia and 1 kinocilium
The cillium of hair cells are connected to?
the tectorial membrane
What happens to hair cells when basilar membrane moves?
they bend
What is the helicotrema?
small hole in cochlea that allows perilymph from scala vestibuli to flow into scala tympani
What is hyperacusis?
abormally acute hearing in affected ear
caused by lesion to facial nerve
What is the role of the inferior colliculus in hearing?
important relay station
responsible for sound localization
What is Jervell-Lange-Nielson syndrome?
rare gentic disroder that causes bilateral congenital deafness
caused by defective ion channels
What does the medial geniculate nucleus do for hearing?
auditory input relating to intensity and frequency
What does the olivocochlear bundle?
inhibitory effect on cochlear nerve
What are components of outer ear?
pinna, external auditory canal, tympanic membrane
What are components of middle ear?
ossicles, tensor tympani and stapedius, oval window/round window, eustachian tube
What are components of inner ear?
cochlea, bony labryrinth, membranous labyrinth
Scala vestibuli communicates with the ______ window?
oval
Scala tympani communicates with the ______ window?
round
What is the site of the primary auditory cortex?
gyrus of Heschl
What type of sensory processing is flocculonodular lobe of cerebellum asssocaited with?
vestibular processing for balance and eye movements
What is flocculonodular syndrome characterized by?
inability to maintain balance while walking/standing
What are gyri called in cerebellum?
folia
What synapse with Golgi (inner stellate) cells?
receive excitatory synapses w/mossy fibers, climbing fibers, and parallel fibers
What cell in cerebellum forms parallel fibers and gives excitatory input to prukinje?
grnule cells
What deep cerebellar nucleus is in the hemispheric zone?
dentate nucleus
What is a intention tremor?
tremors that happen during voluntary movement
What two nuclei make up the interposed nucleus?
emboliform and globose nuclei
Most inputs to cerebellum are?
mossy fibers
What synapses do outer stellate cells make?
receive excitatory from parallel fibers and make inhibitory w/purrkinje
What deep cerebellar nuclei make up the paravermal zone?
interposed nuclei (endoliform and globose)
What is titubation?
condition w/a rhytmic tremor of trunk or head when sitting or tanding
What synapses do unipolar brush cells make?
excitatory w/granule and golgi cells
What is the function of the scala vestibuli?
sound waves propogated in perilymph agitate the vestibular membrane
What fluid is scala media filled with?
endolymph
What is the function of the scala tympani?
the perilymph in it propagates sound waaves toward round window
What is the sound attenuation reflex?
a loud noise heard in 1 ear causes a reflex contraction of both the tensor tympani and stapedius muscles of both ears
(dampens vibrations, prtoects ears)
What is the stria vascularis?
inner surface of the bony labyrinth bordering scala media
produces endolymph
What does the superior olivary nucleus do?
processes binaural cues, including interaural time and level differences
What does the tensor tympani muscle attach to?
malleus
What does the stapedius muscle attach to?
stapes
Whata is tympanic cavity?
middle ear
What separates the scala vestibuli and scala media?
vestibular membrane
What does auditory what pathwaay do?
processes information about the identity of a sound, such as whether it’s a siren or a ring tone
What does the auditory where pathway do?
processes information about the spatial location of a sound, and how to move in response to it
What does otolithic organs refer to?
utricle and saccule
Where do olfactory receptors converge?
on glomeruli on olfactory bulb
What is kinocilium?
only have 1, on hair cells, longer
When do hair cells depolarize?
when stereocilia is pushed toward kinocilium
How are the utricle and saccule orientated?
utricle is horizontal, saccule is vertical
What is the function of the maculae in utricle and saccule?
detecting linear acceleration and gravity
What is nasal mucosa?
membrane lining nasal cavities, produces mucus
