Lecture 8- CN VII - XII Flashcards
1
Q
what detects internal chemical stimuli
A
internal organ chemoreceptors
2
Q
what is the function of internal organ chemoreceptors
A
tracking concentrations of oxygen, glucose, neuroactive hormones and other substances
3
Q
what detects external chemical stimuli
A
gustatory/taste receptors
olfactory receptor neurons
chemosensitive endings
4
Q
where is gustatory/taste receptors
A
oral cavity
5
Q
where is olfactory neurons
A
nasal cavity
6
Q
what does chemosensitive endings detect
A
heat of chili/coolness of methanol
sting of ammonia (nose/eye)
CN V through somatosensory
7
Q
what is papillae
A
gustatory organs of the tongue
8
Q
where is circumvallate papillae
A
posterior 1/3 tongue
oropharynx
9
Q
what innervates circumvallate papillae and the function
A
CN IX for chemical and common Ss stimuli
10
Q
where is foliate papillae
A
middle to posterior lateral tongue
11
Q
what innervates foliate papillae and the function
A
CN V/VII/IX for chemical stimuli
CN V/IX for Ss
12
Q
where is fungiform papillae
A
anterior 2/3 tongue
oral cavity
13
Q
what innervates fungiform papillae and the function
A
CN V/VII for chemical stimuli
CN V for Ss
14
Q
how long does taste receptors last
A
1-2 weeks
basal cells differentiate into new taste receptors
15
Q
what does taste receptors synapse with
A
with dendrites of CN VII/ IX/X through gap junctions
16
Q
where is taste first order neuron
A
ganglia of CN VII/IX/X
17
Q
where is taste second order neuron
A
solitary nuclei
18
Q
what CN is gengiculate ganglia that makes up the first order neuron of taste
A
CN VII
19
Q
what CN is inferior ganglia that makes up the first order neuron of taste
A
CN IX and X
20
Q
what is tastants
A
chemical molecules transduce taste receptor cells
21
Q
what ion channel makes up salty taste
A
leaking ion channel for sodium/potassium ions
22
Q
what ion channel makes up sour taste
A
ionotropic channel with H+ depolarize
23
Q
what ion channel makes up sweet/umami/bitter taste
A
GPCR
24
Q
what is the 6th taste
A
ammonium chloride
like salty or sour ion channel
avoid toxic food
25
where is the third order neuron for taste
VPM of thalamus
26
where does the third order neuron project to
insular lobe
27
what pathway is CN V chemical sensation use
somatosensory pathway
28
where does CN VII exit through the cranium
internal acoustic meatus
29
what nuclei does CN VII use for Ss
spinal trigeminal nucleus
30
what nuclei does CN VII use for Sm
facial motor nuclei
31
what nuclei does CN VII use for Vs
solitary nucleus
32
what nuclei does CN VII use for Vm
superior salivatory nucleus
33
what are the terminal branches of Sm of CN VII
temporal
zygomatic
buccal
mandibular
cervical
posterior auricular
34
what is used for superficial facial expression
facial and scalp m
35
what m does parotid gland pierce
buccinator
36
where does the dorsal nucleus receive projections for CN VII
projections from bilateral anterior cingulate cortex
forehead and scalp
37
where does the ventral nucleus receive projections for CN VII
projections from contralateral cerebral cortex except ACC
lower face
38
what S&S do you expect from a UMN injury affecting the face
UMN= neocortex
can still wrinkle forehead
can smile with humor but not on command
39
what S&S do you expect from a LMN injury affecting the face
LMN= CN VII
no facial expression, flaccid
40
what is the function of the external ear
collect and conduct sound wave through air
41
what is the function of the middle ear
sound wave to vibration
42
what is the function for internal ear
vestibular system
43
what composes the middle ear
tympanic cavity
ossicles
muscles
44
what composes the internal ear
cochlea
45
what is hyperacusis
functional loss of the muscles in middle ear
46
what is ossicles
malleus
incus
stapes
47
what mm make up the middle ear and the function
tensor tympani (CN V)
stapedius (CN VII)
decrease vibration
48
what is the make up of endolymph
high K+
low Na+
49
what is scala vestibuli
continuous to the vestibule, oval window
50
what is scala media
basilar membrane, hearing hair cells
51
what is scala tympani
round window (tympanic cavity)
52
how does hair cells differ from rods/cones
can not regenerate
53
where are the hair cells
basilar membrane (scala media)
cilia in endolymph
54
how is the arrangement of hair cells
1 line inner
3 lines outer
55
what is the function of 1 line inner hair cells
auditory function
56
what is the function of 3 lines outer hair cells
modulatory function
changing shape and size
57
what happens within the ear when sound waves enter
stapes pushes flow of perilymph
expansion of scala vestibuli and tympani
58
what happens with displaced cilia within the ear
changes neurotransmitter release
membrane potential change in cochlear n endings
59
what happens when stereocilia tilts to the taller ones
increase depolarization
60
what happens when stereocilia tilts away from the taller ones
decrease depolarization
61
how is tonotopy maintained
narrow to broad from base to apex, frequency is high to low from base to apex
62
where are the order neurons for auditory pathway
1- spiral ganglion
2- cochlear nuclei
3- inferior colliculus
4- MGN of thalamus
63
what is the function of lateral to medial projection in auditory cortex
what
low to high frequency
64
what is the function of anterior to posterior projection in auditory cortex
where
65
why do we need 2 ears
interaural time difference
interaural intensity difference
locate origin of sound
66
what is interaural time difference
one side need longer time to detect sound wave
more low frequency
67
what is interaural intensity difference
head will block/absorb some sound wave
high frequency
68
what is the location of vestibular
posterior bony labyrinth
69
how does the location of vestibular system change when looking forward
30 degrees elevated anteriorly
70
what are the components of vestibular system
saccule and utricle- otolith organs, maculae in endolymph
semicircular canals
71
what receptors are used in the vestibular system
hair cells, only cilia exposed in endolymph
72
what is maculae
cilia of hair cells covered by layer of CaCO3 crystals (otocomia) in saccule and utricle
73
what is BPPV
dislodge of otoconia in semicircular canal
74
how is maculae aligned in saccule
vertical alignemnt
vertical and AP displacement
75
how is maculae aligned in utricle
horizontal with anterior tilted up to 30 degrees
AP and ML displacement
76
what is the function of ampulla
detect angular acceleration or deceleration
77
how are contralateral ant/post canals aligned in same plane
45 degrees to the sagittal plane
78
how does the kinocilia face in bilateral horizontal canals
towards utricle
79
how does the kinocilia face in bilateral anterior and posterior canals
away from utricle
80
what happens inside the ear when rotating head side to side
activating ipsi but contra horizontal canal
81
what happens inside the ear when rotating head downward to L/R
activating anterior and contra post canals
82
where does the vestibular pathway project to in the cerebral cortex
mainly parietal lobe
83
what are the order neurons in the vestibular system
1- scarpa ganglion
2- vestibular nuclei
3- B VPM of thalamus to integrate proprioception from other body parts in VPL
84
where is signal conducted for VOR
medial vestibular nucleus
85
where is the tracts of axons for VOR
medial longitudinal fasciculus
ascending limb
86
What is VOR
turning head to one side
both eyes rotate opposite to fix on target
87
what mm are activated and inhibited with VOR
activated contra LR6, ipsi MR3
inhibited ipsi LR6, contra MR3
88
what is the function of VCR/VSR if the input is to lateral vestibular nucleus
lateral vestibulospinal tract
ipsi proximal extremity m
89
what is the function of VCR/VSR if the input is to medial vestibular nucleus
medial vestibulospinal tract
bilateral trunk m
90
where is the tract of axons for VCR/VSR
medial longitudinal fasciculus
descending limb
91
where is nuclei for CN IX and X
rostral medulla oblongata
92
what nuclei for CN IX and X has Ss function
spinal tract of trigeminal nerve
93
what nuclei for CN IX and X has Sm function
nucleus ambiguus (Vm and Sm)
94
what nuclei for CN IX and X has Vs function
solitary nucleus
taste and visceral organ sensation
95
what nuclei for CN IX and X has Vm function
IX- inferior salivatory nucleus
X- dorsal vagus nuscleus
96
what is the Ss function of Cn IX and X
external ear
post 1/3 tongue (IX)
pharynx/larynx (X)
97
what is the Sm function of CN IX and X
IX- stylopharyngeus
X- other pharyngeal and larygngeal m
98
what CN is affected if a patient presents with dysphagia and dysarthria
CN X
99
what is the Vs function of CN IX
parotid gland
carotid sinus for baroreceptors and body for SaO2
100
what is the Vs function of CN X
aortic arch- baroreceptors
internal organs until end of midgut
101
what CNs have bilateral corticobulbar innervation
CN IX and X
102
what CNs innervate salivary glands
CN VII- submandibular and sublingual
CN IX- parotid salivary
103
where does CN XI cross the cranium
jugular foramen
104
what is torticollis
ipsi SB with contra RT
tightness, weakness
105
where is CN XII nuclei
proximal medulla
106
what is the difference for UMN and LMN of CN XII
UMN- no obvious atrophy
LMN- atrophy
107
what is the function of CN XII
Sm- tongue m
108
which CN has contralateral corticobulbar innervation
CN XII
