4) Cranial nerves Flashcards
1
Q
Which cranial nerves attach to the midbrain?
A
Occulomotor (III), Trochlear (IV)
2
Q
Which cranial nerves attach to the pons?
A
Trigeminal (V)
Abducens (VI)
Facial (VII)
Vestibulocochlear (VIII)
NB. VII & VIII from cerebellomedullary pontine angle
3
Q
Which cranial nerves are likely to be affected by an acoustic neuroma?
A
Vestibulocochlear
Facial
4
Q
What is the method of testing the olfactory nerve?
A
Offer something familiar to smell
5
Q
What is the method of testing the optic nerve?
A
Acuity - Shellen chart
Colour - ishihar plates
Visual fields - wiggle finger in periphery
Visual reflexes - pupillary constriction
6
Q
What is the method of testing the occulomotor nerve or the trochlear nerve?
A
Draw 2 large H’s with finger - follow with eyes
7
Q
What is the method of testing the sensory part of the trigeminal nerve?
A
Corneal reflex - touch cornea with cotton & should close eyes
Touch face with cotton wool (forehead/cheek/jaw)
8
Q
What is the method of testing the motor part of the trigeminal nerve?
A
Asks patient to clench teeth & open mouth against resistance.
Jaw jerk - put finger on chin and strike with tendon hammer
9
Q
How would you test the abducens nerve?
A
Same as III & IV - eye movements
10
Q
How is the motor function of the facial nerve tested?
A
Crease forehead, close eyes & keep them closed against resistance, puff out cheeks, reveal teeth
11
Q
How is the cochlear part of the vestibulocochlear nerve tested and is the vestibular part normally tested?
A
Cochlear part - Rinne test (tuning fork on mastoid process and then next to ear - 2nd should be louder)
-Weber test (tuning fork on central forehead - is it louder in either ear?)
Vestibulocochlear not normally tested
12
Q
How is the sensory part of the glossopharyngeal nerve tested?
A
Test gag reflex
13
Q
Is the sensory part of vagus easily tested?
A
no
14
Q
How would you test the other components of the vagus nerve?
A
Speaking
Say ahhh - check uvula lies centrally
15
Q
How would you test the accessory nerve?
A
Ask patient to turn head and shrug against resistance
16
Q
How would you test the hypoglossal nerve?
A
Stick tongue out (no deviation)
17
Q
Which cranial nerve is involved in the pupillary light reflex?
A
Afferent - optic (II)
Efferent - occulomotor (III); sphincter pupillae
18
Q
Which cranial nerve is involved in the corneal reflex?
A
Afferent - opthalmic (V1)
Efferent - facial (VII); orbicularis oculi
19
Q
Which cranial nerve is involved in the gag reflex?
A
Afferent - glossopharyngeal (IX)
Efferent - Vagus (X)
20
Q
What 6 structures can be seen on the cerebellum when viewed from the position of the pons?
A
Sup/mid/inf peduncles
Flocculi (x2)
Tonsils (x2)
Nodule
21
Q
What are the main functions of the cerebellum?
A
Receives sensory information and regulates motor movements (eg. posture balance, speech).
Also important in learning motor behaviours
22
Q
What is past pointing?
A
Finger overshoots intended mark (to side of cerebellar damage)
23
Q
What is intention tremor?
A
Tremor during voluntary movements
24
Q
What is dysdiadochokinesis?
A
Inability to perform rapidly alternating movements
25
What is obex?
Bottom V of opening of 4th ventricle
26
How does the optic nerve pass out of the skull?
Through optic canal
27
Does the occulomotor nerve have some parasympathetic component?
Yes
28
What are the 3 parts of the trigeminal nerve?
V1 - opthalmic
V2 - Maxillary
V3 - Mandibular
29
What does the mandibular nerve innervate?
Muscles of mastication
| Sensation to ant 2/3 tongue
30
What does the facial nerve innervate?
Motor - muscles of facial expression
| PS - salivary glands (NOT parotid)
31
What nerve innervates the parotid gland?
Glossopharyngeal
32
What does the glossopharyngeal nerve innervate?
Sensory - pharynx
Parotid gland
Stimulate carotid sinus
33
Other than its parasympathetic function, what else does the vagus nerve supply?
Muscles - larynx, pharynx, palate
34
How does the spinal accessory nerve enter the cranial cavity and after doing so what does it do?
Through foramen magnum, then joins cranial accessory >> accessory nerve
35
What does the hypoglossal nerve innervate?
Tongue muscles (except 1 innervated by vagus)
36
Which cranial nerves exit the cranial cavity through the jugular foramen?
IX, X, XI
37
How many possible fibre types of cranial nerves are there?
7
38
What is a nucleus?
Collection of cell bodies in CNS
39
Where are cranial nerve nuclei located?
Tegmentum of brainstem (all 3 parts)
40
What is the function of a sensory cranial nerve nucleus?
Receives information from fibres entering brainstem. Axons synapse and information is sent to appropriate higher centre
41
What is the function of a motor cranial nerve nucleus?
Receives information from higher centres
| -Fibres synapse >> motor fibres that leave brainstem in cranial nerves
42
Are sensory and motor nuclei located laterally or medially within brainstem?
Sensory - laterally
| Motor - medially
43
Where are the cranial nerve nuclei located in relation to the ventricular system?
Anteriorly (in tegmentum)
44
Why does the occulomotor nerve have 2 nuclei within the brainstem and what are they called?
Carries 2 types of fibres - somatic motor & visceral motor
45
What structures are innervated by the somatic and visceral motor fibres of the occulomotor nerve?
Somatic motor - extraoccular muscles
| Visceral motor - sphincter pupillae & ciliay muscles
46
The 4 autonomic ganglia of the head and neck are associated with which cranial nerve?
Trigeminal nerve
47
What are the names of the 4 autonomic ganglia?
- Ciliary
- Submandibular
- Pterygopalatine
- Otic
48
Autonomic fibres carried in which cranial nerve synapse at the ciliary autonomic ganglion? What nerve are the post synaptic fibres carried in and what is their target?
Pre-synaptic fibres = III
Post-synaptic fibres = v1
Target = sphincter pupillae
49
The pre synaptic and post synaptic fibres of the pterygopalatine ganglion are carried in what nerves and what is the target?
Pre-synaptic fibres = VII
Post-synaptic fibres = v2
Target = lacrimal gland
50
The pre synaptic and post synaptic fibres of the submandibular ganglion are carried in what nerves and have what target?
Pre-synaptic fibres = VII
Post-synaptic fibres = v3
Target = submandibular & sublingual glands
51
The pre synaptic and post synaptic fibres of the otic ganglion are carried in what nerves and have what target?
Pre-synaptic fibres = IX
Post-synaptic fibres = v3
Target = parotid gland
52
What are the 3 autonomic functions of the head and neck?
-Sphincter pupillae
-salivary glands (submandibular/sublingual/parotid)
Lacrimal gland
53
Which 4 cranial nerves contain autonomic fibres?
- Occulomotor
- Facial
- Glossopharyngeal
- Vagus
54
How do the autonomic fibres of the cranial nerves pass to their target organ?
Synapse at autonomic ganglia in trigeminal nerves and travel with these nerves
55
What is the course of the facial nerve and what branches does it give off at which point?
Through internal acoustic meatus - gives off GREATER PETROSAL nerve
Through facial canal - branch to stapedius muscle and chorda tympani
Though stylomastoid foramen - POSTERIOR AURICULAR BRANCH
Divides into 5 MOTOR BRANCHES (temporal/zygomatic/buccal/marginal mandibular/cervical)
56
What does the greater petrosal nerve carry?
PS fibres to lacrimal gland (via pterygopalatine ganglion)
57
What does the chorda tympani nerve from the facial nerve carry?
Fibres carry sensation to ant 2/3 tongue
| Unites with lingual branch of v3 >> sublingual &submandibular glands
58
What are the 5 motor branches of the facial nerve? When are they given off?
```
Temporal
Zygomatic
Buccal
Marginal mandiular
Cervical
```
-After stylomastoid foramen
59
What 2 muscles are supplied by the temporal branch of facial nerve?
Frontalis
| Orbicularis oculi
60
Which muscle is supplied by zygomatic branch of the facial nerve?
Orbicularis oculi
61
Which 2 muscles are supplied by the buccal branch of the facial nerve?
Buccinator
| Zygomaticus
62
Which 2 muscles are supplied by the marginal mandibular branch of the facial nerve?
Orbicularis oris
| Mentalis muscle
63
Which muscle is supplied by the cervical branch of the facial nerve?
Platysma
64
Damage to which cranial nerve leads to inability to swallow food and regurgitation of liquid?
Vagus (X) and/or Glossopharyngeal (IX)
65
Damage to which cranial nerve cause hoarseness?
Vagus - paralysis of intrinsic laryngeal muscles
66
Unilateral tongue atrophy is likely due to damage of which cranial nerve?
Hypoglossal (on one side)
67
Unilateral trapezius atrophy is likely due to damage of which cranial nerve?
Accessory (XI)
68
If one pupil was smaller than the other but both pupils reacted to light, what is this likely due to damage to?
Sympathetic trunk
69
Why does the uvula deviate from the midline on phonation in unilateral vagus nerve damage?
Vagus nerve supplies levator veli palantini
| - deviation away from damaged side
70
Which cranial nerves emerge from the cerebellopontine angle?
Facial (VII)
| Vestibulocochlear (VIII)
71
Which cranial nerve emerges from the interpeduncular fossa?
Occulomotor (III)
72
Which cranial nerve emerges immediately lateral to the medullary olives?
Hypoglossal (XII)
73
Which cranial nerves emerge immediately lateral to the medullary pyramids?
Glossopharyngeal (IX)
| Vagus (X)
74
Which cranial nerve emerges from the dorsal surface of the brain stem?
Trochlear (IV)
75
Which 2 cranial nerves are not true peripheral nerves, why?
Olfactory (I) and Optic (II)
| -CNS structrues
76
Where are the true peripheral olfactory nerves?
Nasal mucosa >> cribiriform plate of ethmoid bone to olfactory bulb
77
The olfactory nerve is most commonly damaged as a result of head injury, how may such damage occur?
Haemorrhage following head injury
78
What is anosmia?
Loss of smell
79
The optic nerve is formed from what embryonically?
Outgrowth of diencephalon
80
Sensory components of the trigeminal nerve supply what?
Skin, teeth, mucous membranes of face
81
Motor components of the trigeminal nerve supply what?
Mastication muscles
Some swallowing muscles
Tensor tympani
82
What is the innervation and function of the tensor tympani?
Trigeminal nerve
| -dampens amplitude of vibrations
83
Where are the cell bodies of most of the trigeminal sensory fibres located?
In trigeminal ganglion
| -at convergence of opthalmic, maxillary & mandibular nerves
84
Through which foramina do the 3 divisions of the trigeminal nerve exit the cranial cavity?
Opthalmic - Superior orbital fissure
Maxillary - foramen rotundum
Mandibular - foramen ovale
85
What are the 4 branches of the mandibular division of the trigeminal nerve?
- Auriculotemporal nerve
- Inf alveolar nerve
- Buccal nerve
- Lingual nerve
86
The maxillary division of the trigeminal nerve gives off what 2 important branches?
Infraoribital nerve
| Sup alveolar nerve
87
Which 2 nerves from the trigeminal nerve hang from the pterygopalatine ganglion?
Greater & lesser palatine nerves
88
What do the greater and lesser palatine nerves supply?
Greater palatine - mucosa, glands and gingiva (hard palate), roof of oral cavity
Lesser palatine - soft palate
89
Which 2 reflexes are tested when examining the trigeminal nerve and which other cranial nerves are involve in these?
```
JAW JERK REFLEX
-trigeminal nerve
CORNEAL REFLEX
-opthalmic nerve (afferent)
-facial nerve (efferent)
```
90
What is neuralgia?
Burning/stabbing pain along a damaged nerve
91
What is trigeminal neuralgia?
Stabbing pain in cheek/lips/gums/chin on 1 side of face
92
What kind of fibres does the facial nerve carry?
Sensory, motor and autonomic (PS)
93
What kind of fibres does the trigeminal nerve carry?
Sensory, motor and carries autonomic (PS)
94
What are the sensory functions of the facial nerve?
Taste - ant 2/3 tongue
| Sensation - floor of mouth, palate & external ear
95
Where are the cell bodies of the sensory fibres running in the facial nerve located?
Geniculate ganglion in facial canal
96
What are the parasympathetic functions of the facial nerve?
Innervation of sublingual & submandibular ganglion
| PS fibres to lacrimal gland and nasal/oral mucous membranes
97
What is the function of the facial nerve fibres running in the greater petrosal nerve?
Form pterygopalatine ganglion
| -PS fibres to mucous glands and lacrimal gland
98
What is Bells palsy?
Facial nerve damage >> paralysis/weakness on one side of face
99
What is hyperacusis?
Over sensitivity to certain sound
| - may be due to facial nerve damage (provide stapedius muscle)
100
How can the vestibular part of the vestibulocochlear nerve be tested?
Weber test - tuning fork in centre of forehead
101
How can the cochlear part of the vestibulocochlear nerve be tested?
Rinne test - tuning fork on mastoid process then next to ear
102
What is an acoustic neuroma?
Tumour affecting vestibulocochlear nerve
103
Dysphagia is caused by damage to which cranial nerves?
Vagus and/or glossopharyngeal
104
What is dysphagia?
Difficulty swallowing
105
What is dysarthria?
Poor articulation
106
Which nerves are involved in the gag reflex?
Glossopharyngeal (IX) - afferent
| Vagus (X) - efferent
107
Is the glossopharyngeal nerve mostly sensory or motor?
Mainly sensory
108
What sensory information is carried in the glossopharyngeal nerve?
Post 1/3 tongue
Chemoreceptors & baroreceptors in carotid body
Cutaneous from ear
109
What does the PS component of the glossopharyngeal nerve supply?
Parotid gland (via otic ganglion)
110
The vagus nerve provides PS innervation to what?
Thoracic and abdominal viscera
111
What does the vagus nerve carry motor fibres to?
Striated muscle
112
What is the vagus nerve joined by? What do they supply together?
Cranial root of accessory nerve
| -striated muscles of palate/pharynx/larynx
113
The functioning of the vagus and cranial accessory nerves can be tested by asking the patient to say aah and observing the movements of the soft palate, what normally happens?
Ulvula should move anteriorly and not deviate
114
Do the spinal and cranial roots of the accessory nerve have the same function?
No
115
What is the origin of the spinal part of the accessory nerve?
Rootlets from upper cervical cord
116
Do the spinal and cranial roots of the accessory nerve have the same function?
Through foramen magnum
117
What happens once the spinal part of the accessory nerve runs into the cranial cavity?
Joins cranial accessory nerve briefly & travels through jugular foramen
-separates >> SCM and trapezius
118
How would you test the functioning of the spinal root of the accessory nerve?
Turn head and shrug shoulders
119
What does the hypoglossal nerve supply?
Motor - intrinsic & extrinsic muscles of tongue
120
How would you assess the functioning of the hypoglossal nerve?
Protrude tongue - no deviation
121
What happens to PS and S fibres in the 4 autonomic ganglia of the head?
- Pre and post synaptic parasympathetic fibres synapse here
| - Sympathetic pass through without synapsing
