Cranial nerve anatomy Flashcards
1
Q
Foramen of CN I
A
Cribiform plate of ethmoid bone
2
Q
Foramen of CN II
A
Optic canal
3
Q
Foramen of CN III
A
Superior orbital fissure
4
Q
Foramen of CN IV
A
Superior orbital fisure
5
Q
Foramen of CN V
A
V1 - Superior orbital fissure
V2 - foramen rotundum
V3 - foramen ovale
6
Q
Foramen of CN VI
A
Superior orbital fissure
7
Q
Foramen of CN VII
A
Internal acoustic meatus
8
Q
Foramen of CN VIII
A
Internal acoustic meatus
9
Q
Foramen of CN IX
A
Jugular foramen
10
Q
Foramen of CN X
A
Jugular foramen
11
Q
Foramen of CN XI
A
Jugular foramen
12
Q
Foramen of CN XII
A
Hypoglossal canal
13
Q
Intracranial route of the trigeminal nerve?
A
Inferior to edge of tentorium cerebelli between posterior/middle cranial fossa
14
Q
Extracranial route of the trigeminal nerve
A
Sensory axons from all 3 divisions course from superficial and deep structures posteriorly back towards respective skull formaninae
Motor of V3 from foramen ovale to skeletal muscles supplied
15
Q
CNV1 sensory innervation
A
Upper eyelid Cornea Conjunctiva Skin of foot, bridge and tip of nose Upper anterior nasal cavity and paranasal sinuses Anterior and posterior cranial fossae
16
Q
CNV2 sensory innervation
A
Skin of lower eyelid Skin over maxilla Ala of nose Skin and mucosa upper lip Maxillary teeth and soft tissues Floor of nasal cavity and palate Maxillary sinuses Lower posterior nasal cavity
17
Q
CNV3 sensory innervation
A
Skin over mandible and TMJ apart from angle of mandible Middle cranial fossa Mandible Anterior 2/3 tongue Floor of mouth Buccal mucosa Mandibular teeth
18
Q
True/false - the great auricular nerve is a branch of a division of the trigeminal nerve
Also what does it supply?
A
False - it is C2,3 nerve roots of cervical plexus
supplies skin over angle of mandible and part of ear
19
Q
Motor innervation from trigmeninal nerve?
A
Tensor veli palatini tensor tympani masseter temporalis medial/lateral pterygoid mylohyoid anterior belly digastric
20
Q
Where is the facial nerve connected to the CNS
A
pontomedullary junction
21
Q
describe the path of the facial nerve
A
Directly to IAM and passes through temporal bone and out SM foramen
Passes through facial canal and meets geniculate ganglion to give off GP nerve
carries through facial canal to give off chorda tympani
last remaining is all motor
22
Q
what does most of the somatic motor supply pass through but not supply and what are the 5 branches of the facial nerve supplying motor innervation
A
parotid gland to zanzibar by motor car Temporal Zygomatic Buccal Mandibular Cervical
23
Q
what does the chorda tympani supply and what nerve does it connect with
A
lingual nerve of CNV3
SS ant 2/3 tongue
parasympathetic for secretomotor submandibular and sublingual glands
stapedius muscle
24
Q
where does chorda tympani pass in relation to the middle ear cavity
A
medial to handle of malleus
25
what are th muscles of facil expression supplied by the facial nerve
frontalis
orbicularis oculi
elevators of lips
orbicularis oris
26
where does the glossopharyngeal nerve connect to CNS
lateral superior medulla oblongata
27
general sensory actions of CNIX
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posterior 1/3 tongue
mucosa nasopharynx and oropharynx and some to laryngopharynx
palatine tonsil
eustachian tube
middle ear
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28
special sensory actions of CNIX
vallate papillae to post 1/3 tongue
29
visceral afferent actions of CNIX
carotid baroreceptoe and carotid body chemoreceptors
30
parasympathetic secretomotor actions of CNIX
parotid gland
31
somatic motor actions of CNIX
stylopharyngeus muscle
32
where is the vagus nerve connected to CNS
lateral aspect medulla oblongata inferior to IX
33
describe the path of the vagus nerve up to the abdomen
passes to jugular foramen
descends in carotid sheath and gives off branches to larynx, pharynx, cardiopulmonary plexuses
gives off recurrent laryngeal
the right lies lateral on trachea and left of the laterla aspect aortic arch
34
describe the path of the vagus nerve within the abdomen
pass through on surface of oesophagus as a plexus and become anterior and posteiror vagal trunks in the abdominal cavity
branches to celiac and SM ganglion
gives off splenic, pancreatic, renal and foregut and midgut branches
last axons are at the splenic flexure of the colon
35
sensory testing of CNV
patient to close eyes
touch V1 areas as upper eyelid and tip of nose
touch V2 areas as lower eyelid, cheek, upper lip and nostril
Touch V3 areas as lower lip, chin, low cheek
36
motor testing CNV
Palpate strength and contraction of masseter and temporalis by asking patient to clench jaw
ask patient to open jaw against resistance
37
testing of muscles of facial expression?
puff out cheeky, close eyes tight, frown, smile
38
clinical testing of vagus nerve?
say ah - uvula should lift in midline
swallow small sip water
listen for hoarseness
assess cough
39
true/false - pathology of the uvula pulls it towards the non functioning side
false - away from the non functioning side
40
describe path and innervation of the spinal accessory nerve
connected to CNS by cervical spine nerve anterior rootlets
ascends through foramen magnum and exits jugular foramen
SCM and trapezius
41
testing of the spinal accessory nerve
shrug shoulders
| turn head and look up
42
describe path and innervation of the hypoglossal nerve
via rootlets lateral to medullary pyramids
anterior to hypoglossal canal
descends in neck lateral to carotid sheath
anterior towards tongue at level of hyoid
most muscles of tongue
43
testing of the hypoglossal nerve
stick tongue straight out
44
true/false - injury to the hypoglossal nerve causes the tongue to deviate to the unaffected side
false - it deviates to the affected side
45
describe the path of special sensory smell to the brain by CN I
nerves are in contact with outside world
pick up stimulus and is trnasmitted back to synapse in olfactory bulb and form olfactory tract
then directly connects with posterior inferior frontal and anteromedial temporal lobe
46
function of the 3rd CN
motor to SR, IR, IO, MR
| parasympathetic to ciliary muscle and sphincter pupillae
47
describe where the origin of oculomotor nerve is
found in the superior colliculus of medial midbrain
oculomotor nucleus
parasympathetic supplied sy edinger westphal
pass out interpeduncular fossa to form CN 3
48
describe where the origin of the trochlear nerve is
close to midline of midbrain at inferior colliculus
trochlear nucleus with motor
crosses midline and exits posteriorly
49
describe where the origin of the abducent nerve is
close to midline and exits abducent nucleus at the pontomedullary junction
50
describe where the origin of the hypoglossal nerve is
lowest part of pons and upper medulla at hypoglossal nucleus
51
describe the origin and pathway of the spinal accessory nerve and its exception
arises from cervical spinal cord from accessory nucleus in anterior horn comes together and arcs through jugular foramen and out by the jugular foramen
accessory fibres called cranial accessory are actually part of the vagus nerve and originate from vagal nuclei
52
where does the motor supply of the trigeminal nerve originate
trigeminal motor nucleus, close to pontine terminal nucleus
53
where is the trigeminal sensory nucleus located and what sections is it split into
from midbrain, through pons and medulla to upper 2 segments cervical spinal cord
mesencephalic nucleus
pontine terminal nucleus
Spinal nucleus
54
what trigeminal sensory info reaches the mesencephalic nucleus
proprioception regarding tough
55
what trigmeninal sensory info reaches the pontine terminal nucleus
discriminative touch and vibration
56
what trigeminal sensory info reaches the spinal nucleus
pain and temperature
57
what is the ventral trigeminothalamic tract
connect thalamus to trigeminal nuclei and further connection to higher centres in cortex
most fibres cross midline but not all
58
facial nerve, what are the nuclei associated with it and why
facial motor nucleus - motor to face
solitary - taste sensation
salivatory - parasympathetics
some facial axons for sensory ear arrive at spinal trigeminal nuclei
59
glossopharyngeal nerve, what nuclei is it associated with and why
post 1/3 taste and touch arrives at solitary nucleus, and carotid baroreceptors/chemoreceptors
general sensory from pharynx and post 1/3 tongue and ear arrive spinal trigeminal nucleus
motor to stylopharyngeal originates from nucleus ambiguous
inferior salivatory provides parasympthetic
60
what nuclei are associated with the vagus nerve and why
dorsal motor nucleus - parasympathetic
solitary nucleus receives taste and visceral info from aortic arch baroreceptors
spinal trigeminal receives sensory from ear, upper oesophagus and lower pharynx
nucleus ambiguous delivers motor info to pharynx/larynx and parasympathetic to heart
61
what is arnolds reflex
sensory stimulation in ear leads to cough
| entry of sensory ear info to spinal trigeminal being misinterpreted to solitary tract and prokoking cough
62
where does input to cranial nerves with parasympathetic efferent come from
hypothalamus mainly
63
what is the corticobulbar tract, what nerves does it implicate and where does it pass
part of the pyramidal tract that passes from primary motor cortex, through itnernal capsule to nuclei of CN V, VII, XI, XII
64
describe the bilateral input of the corticobulbar tract and how this can demonstrate differences in bells palsy and stroke
input to the facial nucleus is only bilateral to the upper section of the muscles of the face
the lower part are contralaterally controlled
fully paralysis of one side of the face implicates a facial nerve palsy, but stroke of the face would only implicate the lower half of a facial palsy
65
what is the reticular formation and what does it do
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network of cells with bodies, axons, dendrites in central core brainstem
integrates CN reflex
conduction and modulation pain
autonomic regulation
basic functyion
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66
how does the reticular formation activate the central cortex
ascending reticular activating system
67
a bilateral lesion of the brainstem reticular formation at or above the upper pons leads to what
irreversible coma
