Cranial Nerves Flashcards
1
Q
Is the optic nerve (CNII) sensory or motor?
A
Sensory
2
Q
What is CN III?
A
The Occulomotor nerve
3
Q
What is CN II?
A
Optic Nerve
4
Q
What are the 2 cranial nerves that the midbrain beholds?
A
- Occulomotor nerve (CN III)
- Tochlear nerve (CN IV)
(both are motor)
5
Q
Is the trigeminal nerve (CN V) sensory or motor?
A
Both
6
Q
Where is the trigeminal nerve (CN V) located?
A
Pons
7
Q
The pontomedullary junction holds what 3 cranial nerves?
A
- Abducens CN VI
- Facial CN VII
- Vestibulocochlear CN VIII
8
Q
Is the abducens CN VI sensory or motor?
A
Motor
9
Q
Is the Facial nerve CN VII sensory or motor?
A
Both
10
Q
Is the vestibulocochlear CN VIII sensory or motor?
A
Sensory
11
Q
What cranial nerves stem from the medulla?
A
- Glossopharyngeal CN IX
- Vagus nerve (X)
- Hypoglossal nerve (CN XII)
12
Q
Is the glossopharyngeal cranial nerve sensory, motor or both?
A
Both
13
Q
Is the vagus nerve CN X sensory or motor?
A
Both
14
Q
Is the hypoglossal CN XII sensory or motor?
A
Motor
15
Q
What are the midbrain’s key roles?
A
- Visual system
- Accommodation reflex (e.g. optic sensory nerve in and oculomotor nerve out)
- Pupillary light reflex (e.g. constriction/dilation)
- Contains substantial nigra
- Dopaminergic system (movement/behaviour)
16
Q
What 4 reflexes are associated with the pons?
A
- Jaw-jerk reflex (trigeminal)
- Corneal-blink reflex (facial-trigeminal)
- Tensor tympani stapedius reflux
17
Q
What are the medulla oblongata reflexes associated with?
A
- Swallowing & gag reflex (glossopharyngeal + vagus)
- Cough
- Sneeze
- ## Sight of decussation of many neurons
18
Q
Reticular formation in the midbrain is associated with what?
A
- Wakefulness (circadian rhythm)
- Consciousness
19
Q
Are somatic motor fibres associated with voluntary or involuntary muscles?
A
Voluntary
20
Q
How many cranial nerves are there?
A
12
21
Q
What are the 5 types of cranial nerve fibres?
A
- Somatic motor fibres
- Visceral motor fibres
- General visceral sensory
- General somatic sensory
- Special sensory afferents
22
Q
What is CN I and what is it associated with?
A
- Olfactory nerve
- Special sensory (smell)
23
Q
Where does the olfactory nerve (CN I) originate?
A
They originate at the chemoreceptors of olfacotyr epithelium
24
Q
Where does the olfactory nerve (CN I) enter the cranium?
A
m through foramina
of cribriform plate of the ethmoid bone
25
What is the only cranial nerve to attach directly to the cerebrum?
The olfactory nerve (CN I)
26
What is the second cranial nerve (CN II)?
Optic nerve
27
What is the estimated number of fibres does the optic nerves contain?
Est. 1 million
28
What location does the optic nerve (CN II) have a partial crossover after it moves through the optic canal?
optic chiasm
29
Where does the optic nerve (CN II) terminate?
in lateral
geniculate nucleus, (LGN)
In the thalamus
30
What is the name of cranial nerve III (CN III)?
Oculomotor nerve
31
What is CN III associated with?
chief motor nerve to ocular and extraocular muscles (eye muscles)
32
Where does the oculomotor nerve originate?
Midbrain (mesencephalon)
33
What type of fibres does the oculomotor nerve comprise?
Both somatic and visceral motor fibres
34
How many oculomotor nuclei is in the mesencephalon?
2
35
What are the 4 somatic motor fibres of the eye does the oculomotor nerve supply?
superior rectus
* medial rectus
* inferior rectus
* inferior oblique
36
- What 3 things do the VISCERAL oculomotor nerves supply?
- parasympathetic innervation of
eye via ciliary ganglion
* smooth muscle of pupil
(sphincter pupillae) –
constriction
* ciliary body -accommodation
(change in lens shape)
37
What is the cranial nerve IV? and what is it associated with?
- Trochlear nerve
- innervates the superior oblique muscle of the eye
38
Where does the trochlear nerve originate?
dorsal mesencephalon
39
What cranial nerve runs the longest intracranial course?
- Trochlear nerve (CN IV)
40
What mechanism does the (CN IV) trochlear nerve innervate the superior oliquie extraocular muscle of the eye?
- A pully mechanism
41
What is cranial nerve VI?
Abducens nerve
42
What is cranial nerve VI associated with?
Abduction of eye movements and movement of lateral rectus nerve
43
Where does the abducens nerve originate?
the pons
44
What does the abducens nerve (CN VI) innervate?
the lateral rectus extraocular muscle
45
What does the abducens nerve (CN VI) innervate?
the lateral rectus extraocular muscle
46
What happens if you damage the CN VI abducens nerve?
Cannot move eyeball laterally beyond the midpoint
47
What type of nerve is the abducens nerve?
- Primary motor nerve
48
What are the 3 cranial nerves that innervate eye movement?
- CN III (oculomotor nerve)
- CN IV - Trochlear nerve
- CN VI - Abducens nerve
49
What is the mneuonic for the cranial nerves?
On - Olfactory
On - Optic
On - Oculomotor
They - Trochlear
Travelled - Trigeminal
And - Abducens
Found - Facial
Voldemort -
Vestibulocochlear
Guarding - Glossopharyngeal
Very - Vagus
Ancient - Accessory
Horses - Hypoglossal
50
What are the first 3 cranial nerves in order?
CN I - Olfactory
CN II - Optic
CN III - Oculomotor
51
What are the 3 sensory nerves within the cranial nerves?
CN I - olfactory
CN II - Optic
CN VIII - Vestibulocochlear
52
What is the nmeuonic for idenifying sensory, motor or both cranial nerves in order?
Some
Say
Money
Matters
But
My
Bestie
Says
Big
Brains
Matter
Most
53
What can occur if there are injuries to the CN VI - abducens nerve?
- Intracranial pressure
- Septic thrombosis
- Diplopia
54
What is cranial nerve V?
Trigeminal nerve
55
Is the trigeminal nerve sensory, motor or both?
Both
56
Is the olfactory nerve sensory, motor or both?
sensory
57
Is the optic nerve sensory, motor or both?
Sensor
58
Is the oculomotor nerve sensory, motor or both?
Motor
59
Is the trochlear nerve sensory, motor or both?
Motor
60
Is the trigeminal nerve sensory, motor or both?
Both
61
Is the abducens nerve sensory, motor or both?
Motor
62
Is the Facial nerve sensory, motor or both?
B
63
Is the vestibulochochlear nerve sensory, motor, or both?
Sensory
64
Is the glossopharyngeal nerve sensory, motor or both?
Both
65
Is the vagus nerve sensory, motor or both?
Both
66
Is the accessory nerve sensory, motor or both?
Motor
67
Is the hypoglossal nerve sensory, motor or both?
Motor
68
What are the 4 mixed sensory and motor cranial nerves?
- CN V - Trigeminal
- CN VII - Facial
- CN IX - Glosspharyngeal
- CN X - Vagus
69
What is the largest cranial nerve?
Trigeminal
70
What are the key sensory functions of the trigeminal nerve?
Principal sensory nerve of the head (face, teeth, mouth, nasal cavity, cranial dura)
71
Where does the CN V trigeminal nerve originate?
Pons
72
What are the 3 branches of the CN V - trigeminal nerve?
- Ophthalmic
- Maxillary
- Mandibular
73
How many trigeminal nuclei are there?
4
1 x motor
3 x sensory
74
Are the small roots of the trigeminal nerve innervating motor or sensory roots?
- Motor
75
Wha do the large trigeminal nerve roots innervate motor or sensory mechanisms?
Sensory
76
Name the trigeminal nerve branches and if they are sensory or motor or both.
Ophthalmic nerve (CN V1)-sensory only
* Maxillary nerve (CN V2)-sensory only
* Mandibular nerve (CN V3)-sensory and motor
77
What is CN VII?
Facial nerve
78
What is CN VII associated with?
Innervation of motor control of facial expression
Facial Parasympathetic efferents & sensory afferents
Mixed nerve
79
Where does the CN VII facial nerve originate?
Pons - Cerebellopontine
80
What ganglion is associated with facial nerve sensory neurons?
Geniculate ganglion
81
What are the 5 CN VII facial nerve branches?
1. Temporal
2. Zygomatic
3. Buccal
4. Mandibular
5. Cervical
82
What is the most frequently paralysed cranial nerve?
Facial nerve
83
What are the 2 special sensory branches of the vestibulocochlear nerve CN VIII?
- Vestibular (balance)
- Cochlear (hearing)
84
Where does the CN VIII (vestibulocochlear nerve) terminate?
in vestibular and
cochlear nuclei of pons and medulla
oblongata
85
Where does the vestibulocochlear nerve originate?
vestibular
apparatus and cochlea of
inner ear
86
Where does the vestibular and cochlear nerves separate?
Internal acoustic meatus
87
What is the name of CN IX?
- Glossopharangeal nerve
88
What is the major component of the glossopharangeal nerve CN IX?
- Major is general and special sensory innervation
89
How many fibres are shared with CN X from the glossopharangeal nerve?
2
90
Where does the CN IX glossopharangeal nerve originate?
Upper medulla
91
Where does the minor motor innervation of the glossopharangeal nerve occur?
Head & neck (parasympathetic)
92
What is cranial nerve X?
Vagus nerve
93
Where does the vagus nerve originate?
Medulla oblongata
94
What are the 4 divisions of the vagus nerve?
- Cranial
- Cervical
- Thoracic
- Abdominal
95
What is CN XI?
- Accessory nerve
96
Where does the CN XI accessory nerve originate?
Origin: motor nuclei of spinal cord
Column of anterior (ventral) horn motor neurons. C1-C6
97
What does teh accessory nerve CN XI innervate?
Motor input to neck and upper
back muscles
(sternocleidomastoid and
trapezius muscles)
98
Where does the CN XI accessory nerve enter the cranium?
Via foramen magnum
99
Where does the accessory nerve exit?
Via jugular foramen (with IX & X)
100
What is CN XII?
Hypoglossal nerve
101
What is the CN XII hypoglossal nerve associated with?
Motor input to muscles of tongue
Voluntary control
102
Where does CN XII hypoglossal nerve originate?
Medulla oblongata
