Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BRB Midterm > Pathways > Flashcards

Pathways Flashcards

1
Q

UMN lesions

A
  • hemiplegia: contralateral if lesion in cortex before deccusation; ipsilateral if lesion in spinal after deccustion
  • paresis/paralysis
  • spacitity (increase tone)
  • hyper-reflexia
  • upward going plantar reflex (babinski sign)
  • no/not as much atrophy
  • no fasiculations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

LMN lesions

-6 signs

A
  • ipsilateral weakness because after decussation **
  • usually ind. muscles not grp
  • flaccidity (decrease tone) or normal
  • hypo-reflexia
  • atrophy
  • fasciculations
  • *EXCEPT Trochlear (CN1V) nuclei because they cross at nucleus level! (but if lesion at the CN4 nerve, will be ipsilateral
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

UMN

A
  • 1ry neuron in motor pathway
  • in CNS
  • synapse to LMN
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

LMN

A
  • cell body in brainstem (CNs) /spinal cord (ventral horns)
  • axons in PNS
  • synapse to muscles
  • LMN pathway = “final common pathway”
  • IPSILATERAL innervation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the corticospinal tract pathway

A

-for skilled limb movements
-1ry neuron: 1ry motor cortex
> corona radiata
> post. limb internal capsule > cerebral peduncles > CST in ant pons > pyramids
> deccusate at spinomedullary junction (pyramids)
> descend in lateral corticospinal tract (LCST) in lateral column of spinal cord
> synapse 2ry neuron: cervical and lumbosacral enlargements
> distal limbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which side is affected if CNs are lesioned?

A

IPSI b/c LMN after deccusation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which side is affected if CN nuceli are lesioned?

A

IPSI except for Trochlear nuclei = contralateral

CST tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe Corticobulbar Tract

A

-cortex > brainstem
-motor path for cranial nerves (5,7,9,10,11,12)
-same as CST except through genu of internal capsule
(although 7,11,12 more complicated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which CN does CBTract not innervate?

A
  • sensory CNs

- eye motors : 3,4,6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which CNs are bilaterally innervated? what is the implication?

A
  • CN 5,9,10
  • redundancy - if lesioned on one side in CBTract (UMN), still ok!
  • but lesion at nerve level (LMN) (after CBT > nuclei) > ipsilateral effects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the UMN, LMN lesions involved with the Mastication Nucleus

A

-CNV3: chewing, jaw movements
-UMN lesion: bilaterally innervated > function preserved
-LMN lesion: IPSIlateral defecit:
opening mouth, chewing diff due to paresis/paralysis jaw drop to lesioned side, atrophy of muscles > asymmetrical face

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the UMN, LMN lesions involved with the Nucleus Ambiguus

A

-CN 9, 10: larynx (10), pharynx, speech, swallowing
-UMN lesion: bilaterally inn > func ok
-LMN lesion: IPSIlateral def
gag reflex loss
hoarse voice
sagging palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the UMN, LMN lesions involved with Hypoglossal nucleus

A

-CN 12: tongue movements
-UMN lesion: before decussation > no input to CONTRALateral tongue > tongue protrudes to contralateral side of cortex and paresis/paralysis
-LMN lesion: after decussatin > IPSIlateral to lesion
tongue protrudes
paresis/paralysis
fasciculations then atrophy
*Tongue always goes to side of lesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the UMN, LMN lesions involved with Accessory nucleus

A
  • CN 11: sterno, trap : shoulder shrug and head turn
  • UMN lesion: IPSI for sterno (difficulty turning head to opposite side), CONTRA for trap weakness in should shrug (because UMN of trap crosses before synapsing in nuclei)

-LMN lesion: ipsilateral both muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the UMN, LMN lesions involved with Facial nucleus

A
  • CN 7 - facial expression, taste ant 2/3 tongue, all glands (except parotid)
  • Facial Nucleus is different because it has 2 subnuclei controlled by different UMNs to forehead and face
  • UMN lesion: rostal subnuclei (forehead) is bilaterally inn; caudal (face) is unilateral. Thus, lesion will only affect CONTRA lower face
  • LMN lesion: IPSI face and forehead affected - paralysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe STT

A
  • Spinothalamic tract
  • for pain, T, crude touch
    1: periphery > DRG into dorsal roots then synapse
    2: in dorsal horn > DECUSSATE > CONTRA STT (ventral-lateral white matter of cord) > travels in Spinal Lemniscus in brain stem > synapse at VP thalamus
    3: thalamus > postcentral gyrus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe DCML

A
  • Dorsal column - medial lemniscus
  • for fine touch, vibration, conscious proprioception
    1: periphery > DRG > dorsal horn > ascend via FASCICULUS GRACILIS (medial, leg) /FASCICULUS CUNEATUS (lateral, arm) > synapse in NUCLEUS GRACILIS/CUNEATUS
    2: nuclei > deccusate @ medial lemniscus in brain stem > synapse in VP thalamus
    3: thalamus > postcentral gyrus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the touch submodalities

A 
nociception (tissue damage)
Temp (T)
crude touch
fine touch
vibration
proprioception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Name the 5 sensory modalities and where in cortex they are perceived

A
  1. smell - 1ry olfctory cortex - uncus, amygdala
  2. vision - 1ry visual cortex - alone calcarine fissure in occipital lobe
  3. hearing - 1ary auditory cortex - transverse temporal gyri on superior temporal gyrus
  4. touch - 1ry somatosensory cortex - postcentral gurus
  5. taste - 1ry gustatory cortex - inf. postcentral gyrus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe Somatosensory pathway neurons

A

3 neurons:

  1. pseudounipolar located in DRG or Trigeminal gangion (face)
  2. in dorsal horn of spinal cord or brain stem
    - CROSSES and goes to CONTRA VP thalamus (location of deccusation depends on tract)
  3. thalamus to appropriate cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe clinical expression of an ventral intramedullary lesion
ex: tumour compression from within cord

A

-affect STT
-loss of pain, T at level of lesion, then appears to DESCEND if lesions grows
(distal dermatome further out)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe clinical expression of an ventral extramedullary lesion
ex: meninegoma, disc compression from outside cord

A

-affect STT
-loss of pain, T at level of lesion then appears to ASCEND
(proximl dermatomes more central on cord)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

where is the border between running through fasciculus graciclis vs cuneatus

A

above T6: ascend through cuneatus (no FG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe clinical expression of midline dorsal compression

A

Loss of conscious proprioception, fine touch, vibration sensation legs moving up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is different about somatosensation of the face?

A

1ry neuron goes via CNV to trigeminal ganglion not DRG > synpase then deccusate > VP thalamus, synapse > cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sensory Trigeminal Nuclei (3)

A
  • posterior brainstem
    1. Mesencephalic Nucleus (midbrain)
  • 1ry sensory neurons
  • proprioception of jaw; reflex arc of masticator muscles
    2. Chief Sensory Nucleus (pons)
  • 2ry neurons
  • touch, vibration (like dorsal column for body)
    3. Spinal Trigeminal Nucleus (medulla)
  • 2ry neurons
  • pain, T, crude touch (like STT)
  • fibres enter at pons, descend to medulla to reach nucleus, deccusate and joins SPINAL LEMNISCUS tract to go to thalamus with body signals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is suspended sensory loss?

A

-loss of sensation at level of lesion but above and below is OK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is dissociated sensory loss?

A
  • one side loss STT modalities, while the other side loss DCML mods
    ex: spinal cord unilateral lesion - affect contralateral STT because cross and can’t ascend and ipsilatearl DCML because can’t ascend. deficit below level of lesion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are muscle spindles? How do they work

A

-stretch receptors for muscle - length
-located along striate muscles
-fire on 1a afferent axon
-when muscle contract, spindle get sggy so need intrfusal muscle to contrct to maintain spindle
< alpha-gamma co-activtion: ALPHA to contract muscle, GAMMA to contract intrafusal muscle of spindle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are golgi tendon organs?

A
  • receptor for muscle tension/contraction
  • located along tendons
  • fire on 1b afferent axons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe 1a stretch reflex pathway.

A
  • muscle stretch
  • spindle stretch
  • fires on 1a afferent axon > through DRG > dorsal horn > synapse on ALPHA motor neuron > out ventral horn > Contract muscle = reflex movement
  • while, reflex also contract synergistic muscles and inhibit antagonistic muscles vi 1a inhibitory neurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How are reflexes modulated?

A

reflexes are not hardwired…can be modulated with exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe 1b pathway.

A
  • 1b fire > dorsal horns > synapse on 1b inhibitory neuron > integration node to regulate sensory activity
  • more complicated
  • reflex control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the withdrawal reflex?

A
  • contract one leg while extending other to maintain balance
  • circuit for walking
  • withdrawing when have noxious stimulus (stepping on pin)
  • uses sensory input
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are 4 descending motor pathways?

A
  1. corticospinl
  2. subrospinal
  3. vestibulospinal
  4. reticulospinal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the fncs of descending motor pathways?

A
  • control reflex
  • select motor programs
  • activate motorneurons > muscles
  • activate muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is tone?

A

-resistance as joint moves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is spasticity? What are treatment options?

A

-increased velocity-dependent tone with exagerated stretch reflex (increase amplitude/briskness)
-spastic catch
-Tx: PT, stretching
reduce 1a afferent axons and motorneuron: baclofen
weaken muscle: botulinum toxin reduce ACh release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is clonus?

A

rapid succession of stretch reflex

-ankle dorsiflexion: 3-4 beats is normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the classic hemiplegic posture? cause?

A

-stroke
-one side:
facial droop
flexed arm
pronated wrist
hip circumduction
extended leg
ankle planter flexed

41
Q

What is the clasped-knife phenomenon?

A

-spasticity with flexion reflex

42
Q

What are the 4 cortical sensory modalities? What 1ry sensory modality is needed for each?

A
  • based on 5 touch primary sensories:
    1. graphesthesia (need nociception)
    2. stereognosis (T)
    3. 2-pt discrimination (vibration)
    4. extinction (proprioception, light touch)
43
Q

Classes of receptors: exteroceptors vs proprioceptors vs enteroreceptors

A

extero: light, sound, tissue damage, T, touch, pressure
proprio: muscle, tendon, joints - muscle spindle
entero: viscera

44
Q

Threshold of receptors to fire?

A
  • intensity to activate receptor 50% of time

- tactile sensations need lower threshold than nociception

45
Q

What is receptor adaptation? Rapid vs slow adapting Receptors?

A
  • reduce firing with continued stimulation
  • rapidly adapting R: report onset and end. good for high-f vibration, movements
  • slowly adapting R: continuous firing. good for pressure, shape, low f vibration, intensity
46
Q

What is a receptor field size?

A

area of skin innervted by same sensory axon

  • within area, can’t do 2pt discrimination
  • plastic - alter by use/amputation
47
Q

How is sensitivity of nerves coded? where is it highest?

A

increase number of innervation

-highest in fingers, mouth, genitals

48
Q 
Describe classes of somatosensory nerve fibres:
Aalpha
Abeta
Agamma
A delta
B
C
A

Aalpha - fastest, biggest xons
-1a fibres: limb positio, motion, muscle spindle extrafusal muscle
Abeta
-1b fibres: golgi - tension
-II: skin for consciou proprio, touch, pressure, vibration
Agamma: spindle fibre intrafusal muscle
A delta: fast pain, cold, hair follicles
B: pregang ans, white rami
C: slow pain, warmth, postgang ans grey rami

49
Q 
How is sensory coded?
intensity
location
modality
quality
A

intensity - f of APs
location - receptive fields of axons
modality - fibre type
quality - popultion of firing axons

50
Q

Relay - Projections along somatosensory pathway of DCML? why?
ex: touch stimulus

A

ex: touch stimulus activating DCML
1. project to STT to inhibit pain perception
2. project to reticular formation to stimulate alertness
3. project to superior colliculus to drive orientation

51
Q

3 sensory integrations on somatosensory pathway of DCML at 2ry neuron?

A
  1. cortical descending inhibition refines attention
  2. lateral inhibition sharpens localization - 2nd neuron inhibits neighbours from firing
  3. no mixing of modalities
52
Q

Describe the 1ry somatosensory area

A
  • postcentral gyrus

- 4 regions: 1 for mechnoreceptors, 1 proprioreceptors

53
Q

Describe the 2ry somatosensory area

A
  • inferior on postcentral gyrus
  • inputs from 1ry S1 and thalamus
  • projects to medial temporal lobe via insula
  • TACTILE MEMORY: graphestesia, stereognosis
54
Q

Describe the sensory association area

A
  • bt postcentral gyrus and occipital lobe
  • integrate ss and visual
  • project to motor cortex
55
Q

What are sources of input to cerebellum?

A
  1. CONTRA: Motor cortex > Pontine nucleus > middle CB peduncle > cerebrocerebellum

IPSI:

  1. vision, hearing > sup. and inf colliculi > superior CB p > spinocerebellum
  2. vestibular apparatus and proprioception > inferior CB p > vestibulocerebellum
56
Q

Which side is affected if cerebellar is issue? why?

A

ipsilateral b/c double crossed

  1. leaves cerebellum, cross over to contralateral cortex
  2. descending motor pathway crosses over @ pyramids
57
Q

What are signs of cerebellar damage?

A
  • ataxia: speech, limbs, wide base gait, “drunk”
  • dysmetria: failure to coordinate multiple joints - overshoot and correct
  • intention tremor: oscillation as approach target
  • dysdiadochokinesia: trouble with repetitive movements
  • nystagmus
  • vertigo
58
Q

What is the cerebellum? fncs?

A
  • 10% brain V
  • 50% brain neurons
  • adjust output of descending motor pathways
  • coordination, eye movement, speech, balance
59
Q

What are teh 3 fnc lobes of cerebellum? where do they output?

A
  1. cerebrocerebellum > dentate nucleus > sup CB p > red nucleus > VL thalamus > motor, premotor cortex: skilled motor movements, learning, planning
  2. vestibulocerebellum (floculonodular lobe) > vestibulo nucleus via inf CB p: balance, eyes and head movements
  3. spinocerebellum (vermis, paravermis) > descending motor systems via inf CB: locomotion, limb movements position
60
Q

Head-eye movements

A

-Head turn
-endolymph turn in OPPOSITE direction > hair cells
>excitation on same side of turn
>inhibition on opposite side of turn

61
Q

What is the vestibular ocular reflex?

A
  • head move, eyes move in opposite direction
  • endolymph moves in opposite directon > activaet Abducens Nucleus > activate ipsilateral occulomotor nucleus and contralateral abducens nucleus
62
Q

What is nystagmus and 4 ways to induce?

A

: repetitive eye movements, sign of vertigo
jerky/pendular oscillations, direction defined by fast phase

  1. Disease:
    - cerebellar damage
    - retina
    - meniere’s disease
    - VIII neuropathy
    - brainstem damage
  2. Toxicity: alcohol, antiobiotics
  3. spinning > nystagmus fast phase in direction of spin, slow phase in trying to maintain fixation
  4. Optokinetics
63
Q

What are the semi-circular canals?

A
  • detect angular velocity
  • 3 at 90deg of each other
  • contain endolymph > moves hair cells > bend > depolarization/repolarization
64
Q

What is utricle? saccule?

A
  • contain of Otolith organs, hair cells, crystals
  • detect linear motion
  • utricle: horizontal plane
  • saccule: vertical plane
65
Q

What is the purpose of the Vestibular system?

A

=VOR: keeps eyes fixed durign head movements

  • vestibulo-colic reflex: keep head balanced during body movements
  • upright
  • perception of acc/deccleration, angular motion
66
Q

What is vertigo?

A
  • hallucination of movements

- not dizziness

67
Q

What are inputs to basal ganglia?

A

via striatum (putamen + caudate) from cortex

68
Q

What are outputs from basal ganglia?

A

via globus pallidus interna > thalamus > motor cortex

69
Q

What is hemiballismus?

A
  • involuntary unilateral large flinging movements
  • rotatory
  • lesion to contralateral subthalamic nucleus
70
Q

What is athetosis?

A

continuous slow sinuous writhing

-involuntary flexion, extension, pro-supination

71
Q

What is chorea?

A

-random, purposeless, flitting movements

72
Q

What is dystonia?

A

-persistant muscle contraction

73
Q

4 signs of Parkinson’s D? Tx?

A

TRAP

  • tremor
  • rigidity
  • akinesia
  • postural instability
74
Q

What is the basal ganglia? Fnc?

A
  • extrapyramidal motor system
  • doesn’t interact with spinal cord directly
  • motor planning, cognition
75
Q

Why is nigrostriatal projection importnt?

A
  • substantia nigra contains dopaminergic neurons

- dopamine pathway to striatum

76
Q

Describe the direct pathway from basal ganglia > cortex using dopamine

A

Substantia nigra > dopamine > striatum > inhibit direct pathway to Globus pallidus interna > less inhibition to thalamus > excite thalamus to cortex

77
Q

Describe the indirect pathway from basal ganglia > cortex using Dopamine

A

Substantia nigra > dopamine > striatum > inhibit indirect pathway to Globus pallidus externa and inhibit subthalamic nucleus > inhibit globus pallidus interna > less inhibition to thalamus > excite thalamus to cortex

78
Q

Signs of Basal ganglia issues?

A
  • dystonia
  • dyskinesia
  • athetosis
  • chorea
  • hemiballism
  • parkisonism (hypokinetic, while the others are hyperkinetic above)
79
Q

What is dyskinesia?

A

-involuntary, rthmic mvoements (tongue jaw face)

80
Q

What is Huntington’s disease?

A

-wasting of caudate, putamen, cortical atrophy

81
Q

What are tics? What is an associated dissorder?

A
  • repeated suppressible actions vis urge involving basal ganglia
  • Tourette’s syndrome
82
Q

What is the rule of 4 for brainstem?

A
  1. 4 M midline structures: motor pathway, medil lemniscus, medial longitudinal fasciculus, motor nuclei and nerves
  2. 4 motor nuclei midline: 3,4,6,12
  3. 4 S side structures: STT, spinocerebellar tract, sensory nucleus of CNV, sympathethic pathway
  4. 4 CNs in each medull, pons, midbrain or above
83
Q

What is dyskinesia?

A

mix of choreaform, ballistic, dystonic movements

complication with ldopa use

84
Q

How is pitch coded? What can we perceive?

A
  • frequency: changes in air pressure per seconds
  • normal : 20Hz-20KHz
  • encoded by firing of specific axons at particular place along basilar membrane that resonate the most at that sound wave > signal is highest
85
Q

Pathway sense organ > primary auditory cortex.

A

Cochlea > spiral ganglion > CN VIII > synpse on IPSI cochlear nuclei > project BIlaterally to suprior olive > inferior colliculi > Medial geniculate nucleus of thalamus > 1ry auditory cortex (temporal lobe).

86
Q

How is loudness coded?

A
  • intensity - difference in pressure. number of APs

- decibels (log scale)

87
Q

What happens in the middle ear?

A
  • air filled space-
  • tympanic membrane > oval window
  • ossciles: MIS
88
Q

What are the ossicle muscles in middle ear? innervation?

A 
tensor tympani (V3)
stapedius (VII)

lesion : hypercusis

89
Q

Describe the inner ear.

A 
-fluid filled cavity
contain bony labyrinth and membranous labyrinth
-2 sense organs:
1. Vestibular apparutus
2. cochlea
90
Q

Describe the cochlea.

A
  • bony labyrinth spiral around MODIOLUS (contain nerves and blood vessels)
  • cross section looks like 3 spaces but actually continuous at apex of spiral
91
Q

What are the 3 scala of cochlea? What is inside each? what is membrane bt them?

A

Scala vestibuli - perilymph (stapes hit oval window here to start pressure wave)
-vestibulr membrane-
Scala media (Membranous labyrinth)- endolymph
-basilar membrane-
Scala tympani - perilymph
-round window - release pressure

92
Q

What is endolymph vs perilymph?

A

endo ~ ICF, high in K+, secreted by stria vascularis in Scala media of cochle

peri ~ CSF

93
Q

What is the spiral lamina (ear)?

A
  • osseous extension (spike of bone from spiral centre) from modiolus into cochlear space. attach basilar membrane and determine width of membrane.
  • base > apex: basilar membrane gets wider because lamina is shorter, cochlea narrows
94
Q

What is the organ of Corti?

A

aka Spiral organ
on basilar membrane (in Scala media)
-covered by tectorial membrane
-contain receptor cells: convert mechanical E > action potential > CNVIII

95
Q

What are stereocilia?

Outer hair cells vs inner hair cells?

A

hair cells hve stereocilia = mechanicoreceptors: bend > depolarization.
rows on the hair cell. tallest AWAY from modiolus
-OHCs - extend through endolymph into tectorial membrane. Amplify input.
-IHCs - extend into endolymp but not tectorial membrane. More important for input coding.
-more OHC (3:1) but IHC connected to more neurons

96
Q

How is sound transduced once it reaches cochlea?

A

stapes hit oval window > endolymph moves > perilymph moves > basilar membrane moves > axons at maximal activtion along basilar membrane fires:

  1. vibrations of basilar membrane moves DOWN: hair cells move outward > tip of stereocilia INward toward modiolus, away from tallest = hyperpolarization
  2. basilr membrane moves UP > hair cells move inwrd > tip of stereocilia outwward AWAY from modiolus, toward tallest sterocilia = depolarization
97
Q

How do receptor potentials in hair cells work?

A

stereocilia tips have K+chnnels (perilymph high in K+)

  • when bend toward tallest: channels increase conductivity > depolarization > Ca2+ at base of hair cell > vesicles secrete NT > spiral gnglion neurons&raquo_space;>
  • -when bend away tallest: channels decrease conductivity > hyperpolarization > decresase NT release
98
Q

where is lesion if there is unilateral deafness?

A

below Cochlear nuclei (can’t be subcorticl/cortical because of bilateral innervation)
-ear, cochlear nerve, cochler nucleus

BRB Midterm (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions