Cranial Nerves V, VII Flashcards
1
Q
CBO of Facial SVE
A
Pharyngeal Arch II
2
Q
Function of Facial SVE
A
Muscles of facial expression
3
Q
CBO of Facial GVE
A
Superior Salivatory Nucleus
4
Q
Termination of Facial GVE
A
(Parasympathetic) Submandibular and Pterygopalatine ganglia
5
Q
Facial GSA innervation
A
Skin of ear
6
Q
CBO and Destination of Facial GSA
A
Geniculate ganglion -> Trigeminal spinal nucleus
7
Q
Facial SVA innervation
A
Anterior 2/3 of tongue
8
Q
CBO and Destination of Facial SVA
A
Geniculate ganglion -> Solitary nucleus
9
Q
Facial GVA innervation
A
Palatine tonsil & posterior nasal cavity
10
Q
Fibers of VII make up ____ roots
A
2
11
Q
Facial nerve proper consists of ____ fibers
A
SVE
12
Q
_______ __________ of VII contains GVE and sensory fibers
A
Nervus intermedius
13
Q
Fibers of VII exit the skull through the ___________ ________
A
Stylomastoid foramen
14
Q
Facial n. passes through the ________ ______ where a plexus is formed
A
Parotid Gland
15
Q
Superior salivatory nucleus -> _______ ________ n. -> Pterygopalatine ganglion
A
Greater Petrosal n.
16
Q
Superior salivatory nucleus -> ________ ________ n. -> Submandibular ganglion
A
Chorda Tympani n.
17
Q
Action of Facial SVE
A
Muscles of facial expression - Closes eye; closes lips
Stapedius m. - modulates sound volume
18
Q
Action of Facial GVE
A
Salivation and Lacrimation
19
Q
Bell’s Palsy def and symptoms
A
Facial n. lesion
- Irritation of cornea
- Paresis of facial mm. above and below the eye
- Hyperacusis - increased sensitivity to noise
- Reduced lacrimation & salivation
- Numbness or pain of the ear, tongue, or face
20
Q
Facial n. Paralysis
A
Complete over half the face
21
Q
Which Facial n. component passes through the facial canal?
A
Both Facial n. proper and and Nervus intermedius
22
Q
After coursing through the facial canal the facial n. turns to form the ________ _____
A
external genu
23
Q
What is found at the external genu?
A
The geniculate ganglion
24
Q
Intermediate nerve fibers and some fibers of the facial n. exit before reaching the ________ ________
A
Stylomastoid Foramen
25
Which branches of Facial n. exit prior to the Stylomastoid foramen?
Stapedial n., Branch to pterygopalatine ganglion, Chorda tympani n.
26
Crocodile tears
Unilateral tearing seen in anticipation of, and during meals
- History of Bell's Palsy
- Parasympathetic fibers to submandibular ganglion have been re-routed to pterygopalatine ganglion
27
Supranuclear lesion (above nucleus)
- Paralysis (paresis of muscles of facial expression below level of the eye
- Paralysis is located on the side opposite the lesion
28
Hyperalgesia
noxious stimulus that evokes pain sensation greater than normal
29
Allodynia
non-noxious stimulus that evokes pain sensation
30
Inflammatory pain
- caused by tissue damage
- produces hypersensitivity at site and in adjacent normal tissue
- resolves when disease is controlled
31
Neuropathic pain
- Caused by nervous system lesion independent of peripheral pathology
- Pain persists long after initiating event has healed
32
Peripheral Sensitization
- Stimulation of afferent ending ("activation")
| - Repeated stimulation produces "autosensitization" (hyperalgesia)
33
Sensitizing agents
Bradykinin, Norepinephrine, Prostaglandins, Serotonin
34
True or False: Peripheral sensitization is non-reversible
False: Quickly reversible
35
Central Sensitization
Intense and prolonged stimulation of nociceptive fibers
36
Central Sensitization can result in:
Modification of peripheral receptor due to:
- Increased gene expression resulting in
1. Enhanced receptor sensitivity
2. Increased number of receptor sites
37
Central Sensitization - Wind-up location
Posterior horn/trigeminal spinal nucleus
38
Enhanced activity of C (pain) fibers results in:
1. Increased sensitivity of glutamate receptors
| 2. Suppressed activity of inhibitory interneurons
39
Microglia morphological states
Surveillance State (resting)
- Ramified configuration with small (micro) central region and long narrow processes
Enhanced Response State (activated)
- Enlarged, amoeboid configuration
40
Microglia are physically active with ____ and _____ _________ elements
Pre and Post synaptic
41
Astrocytes in Active State
Normal
- Astrocytes interact between neuron and nearby vascular supply
- They recycle neurotransmitters including glutamate (glutamate - glutamine shuttle)
42
Astrocytes in Reactive State
During a state of Pain hypersensitivity
- Release factors that
1. enhance synaptic activity
2. promote microglia into "Enhanced Response State"
43
In response to peripheral inflammatory situation astrocytes:
Promote microglia toward Enhanced Response State
44
ATP is one of several _________ factors
Promotor
45
Microglia release ___________ __________ which activate neurons within the spinal cord dorsal horn / trigeminal spinal nucleus
Inflammatory Cytokines
46
If peripheral inflammatory situation resolves:
Microglia Enhanced Response State returns to its resting state
47
Chronic Neuropathic Pain
Due to long-term change in central nervous system structure
48
In Chronic Neuropathic Pain, Microglia:
remain in Enhanced Response State that continue to release inflammatory cytokines
49
In Chronic Neuropathic Pain, Astrocytes:
continue to promote activation of microglia in part through positive feedback from microglia
50
Three Divisions of Trigeminal Nerve (CN V) and their innervations
```
Ophthalmic division (V1)
- Upper face
- Sensory only
Maxillary division (V2)
- Middle face
-Sensory only
Mandibular division (V3)
- Lower face
- Sensory and motor
```
51
Borders between skin areas served by each division are
Sharp (unlike overlap of afferent spinal nerves)
52
about 2/3 of fibers in CN V are
C Fibers
53
CBO of Trigeminal SVE
trigeminal motor nucleus
54
Course of Trigeminal SVE
mandibular division (V3)
55
Termination and Action of Trigeminal SVE
Voluntary control of striated muscles (Arch I)
| - terminate in muscles of mastication
56
Trigeminal Motor Nuclei location
Dorsolateral Pontine Tegmentum
57
Supratrigeminal nucleus is part of ____ and responsible for ______
the immediately adjacent reticular formation; responsible for rhythmic actions of the motor neurons
58
CN V motor root
Fibers exit through the pons as the smaller motor root. Larger sensory root accompanies it
59
Jaw closing muscles include
Temporalis and Masseter muscles
60
Jaw opening muscles include
digastric and infrahyoid muscles
61
Jaw opening strength is _______ to determine than jaw closing strength
Easier
62
Trigeminal GSAp
- Serves neuromuscular spindles of mastication muscles
| - Pressure/tension receptors in periodontal ligaments
63
CBO of Trigeminal GSAp
Unipolar cell bodies, Trigeminal mesencephalic nucleus
64
Trigeminal GSAp project to:
Trigeminal motor nucleus, Suprageminal nucleus
65
What nerve controls distance between mandible and maxilla?
Trigeminal GSAp
66
The trigeminal mesencephalic nucleus is found:
in the rostral pons and mesencephalon adjacent to the ventricle
67
The trigeminal mesencephalic nucleus consists of ________ cells of _______ _____ origin
Unipolar; Neural Crest
68
The nerve CB of the trigeminal mesencephalic nucleus are
are scattered on either side of the trigeminal mesencephalic tract located medially
69
Lower motor neuron lesion _______ jaw-jerk reflex
Attenuates
70
Upper motor neuron lesion ________ jaw-jerk reflex
May accentuate
71
Trigeminal GSAe
Skin of face, oronasal mucous membranes, teeth, dura mater
72
Trigeminal Spinal Nucleus subnuclei
Rostral -> Caudal
| Pars oralis, Pars interpolaris, Pars caudalis
73
Trigeminal GSAe sensations
Pain, Crude touch, temperature
74
In Tooth pulp, 70-80% of fibers are:
A-delta and C fibers
75
In Tooth pulp, 10-30% of fibers are:
A-beta fibers
76
Tooth pulp fibers project to:
```
Trigeminal principal sensory nucleus (heaviest)
- shared with pars oralis
Trigeminal Spinal Nucleus
- Pars oralis (heaviest - shared)
- Pars interpolaris (modest)
- Pars caudalis (light)
Upper Cervical Spinal Cord
```
77
The Pars Oralis receives input from
Intraoral and perioral structures
78
The Interpolaris proper is responsible for
Activation of trigemino-autonomic reflexes
79
The Caudalis-Interpolaris transition zone
1. Not somatotopically organized
2. Responds to pain stimuli from many areas served by the CN V
3. May be involved in activation of pain suppression mechanisms
80
The Pars Caudalis is located in
Medullary Posterior Horn (MPH)
81
Somatotopic Organization of Pars Caudalis
- Inverted representation of face
| - Onion peel - rostral (oral) to caudal (peripheral face) organization
82
Pars Caudalis contains primarily
Pain fibers
83
The Substantia gelatinosa of the Pars Caudalis
- Contains excitatory and inhibitory interneurons
| - Receives raphe spinal tract fibers (serotonin)
84
The Pars Caudalis receives afferents from Cranial nn.
VII, IX, X
| all from Ear
85
The Pars Caudalis is a target of
1. A-delta and C fibers
2. Fibers from superficial structures including oral cavity and TMJ
- convergence may be basis of referred pain
86
Estrogen Receptors are present in the:
Trigeminal spinal nucleus, Parabrachial nucleus, Periaqueductal gray, Hypothalamus
87
High estrogen levels and stress increase activity in __________________ in response to pain
Trigeminal spinal nucleus caudalis laminae
88
GABA normally _________ pain-induced activity in trigeminal spinal nucleus caudalis
dampens
89
GABAergic activity is __________ by high estrogen levels
suppressed
90
Trigeminocardiac Reflex stimulation
1. Eye and Periocular structures (oculo-cardiac reflex)
2. Nasal Mucosa
3. Face (Diving Reflex)
4. Needle insertion into trigeminal nerve
5. Temporomandibular joint surgery
6. Traction on trigeminal nerve during neurosurgery
91
Trigeminocardiac Reflex results in:
1. Bradycardia (increased vagal tone)
- Solitary nucleus, nucleus ambiguus
2. Apnea
3. Arterial hypotension
4. Gastric hypermobility (fullness, nausea, vomiting)
92
Trigeminal Neuralgia
```
Excruciating, lancing pain
- usually unilateral
Affects V3 70%, V1 < 5%
Other considerations:
- Trigger point
- Onset in middle age
- Often responds to drug therapy
- Microvascular decompression may be effective
```
93
Trigeminal Principal Sensory (chief or pontine) Nucleus
Homologous with the posterior column nuclei
- two point discrimination
- vibratory sense
94
Ascending Trigeminal Pathways termination
ventral posteriomedial nucleus of the thalamus (VPM)
95
The Ventral Trigeminothalamic tract projects
contralaterally to VPM
96
The Dorsal trigeminothalamic tract projects
bilaterally to VPM
97
Both Ascending Trigeminal Pathways give off fibers to
nearby reticular formation
98
Corneal reflex
Stimulates cornea via Trigeminal nerve
99
Corneal reflex trigeminal nerve projects to
Trigeminal principal nucleus
Trigeminal spinal nucleus
- Relays bilaterally to facial nucleus
100
In Corneal reflex, which nerve closes eye?
Facial n.
101
Direct Corneal reflex
Stimulates cornea and ipsilateral eye closes
102
Consensual Corneal reflex
Stimates cornea and contralateral eye closes
