Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Semester 3 - Head and neck > 8. Cranial Nerves Continued > Flashcards

8. Cranial Nerves Continued Flashcards

1
Q

What is CNVII and where does it originate from?

A

Facial nerve, lateral lower pons (pontomedullary junction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the path of CNVII?

A

Lower pons → Enters petrous bone via Internal auditory Meatus → 3 branches within petrous bone → Exits via sylomastoid foramen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What type of fibres are in CNVII?

A

Special sensory, Motor, parasympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What autonomic fibres are in CNVII and what do they innervate?

A

Parasympathetic: Lacrimal glands, nasal glands, Salivary glands (except parotid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the special sensory function of CNVII?

A

Anterior 2/3 of tongue (taste)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the motor function of CNVII?

A

Muscles of facial expression, Stapedius (in middle ear)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where does the facial nerve first branch and what is the name of the branch?

A

At the geniculate ganglion in the petrous bone

- first of the three intrapetrous branches = greater petrosal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the route of the greater petrosal nerve and where does it branch?

A

Leaves petrous bone and branches at pterygopalatine fossa to lacrimal, nasal and oral/palatal mucosal glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the 2nd branch of the facial nerve?

A

nerve to stapedius - branches in middle ear cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of fibres are in the greater petrosal nerve?

A

purely parasympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what type of fibres are in nerve to stapedius?

A

purely motor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If a lesion affects the nerve to stapedius how may it present?

A

hyperacoustic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the third branch of the facial nerve in the petrous bone

A

chorda tympani

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What fibres are in the chorda tympani nerve and what are their functions?

A

Parasympathetic: Salivary glands

Special sensory: Anterior 2/3rd tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe the route of the facial nerve after it passes through the stylomastoid foramen?

A

now only contain motor fibres

- route through parotid gland and gives of five terminal extra cranial branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the 5 extra cranial branches of facial nerve?

A

To Zanzibar By Motor Car

temporal
zygomatic 
buccal
marginal mandibular
cervical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is CNVII tested?

A

Mainly by testing muscles of facial expression (and the corneal reflex orbicularis oculi to close the eye)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why can symptoms of CNVII lesion vary?

A

Depends on where along the nerve route the pathology is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how do facial nerve lesions present?

A

Unilateral facial droop +/- reporting symptoms due to absence of other facial nerve functions:
Hyperacusis (noise sensitivity), dry eyes, altered taste, dry mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why can middle ear and parotid pathology affect CNVII?

A

Occurs in petrous bone which facial nerve passes through. Passes through parotid gland.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are some causes of facial nerve lesions?

A
  • Lesions in/around internal acoustic meatus & posterior cranial fossa tumours - point of vulnerability
  • Basal skull fracture (involving petrous bone)
  • Middle ear disease
  • Inflammation in facial canal…facial nerve palsy e.g. Bell’s Palsy, Ramsay-Hunt Syndrome
  • Parotid disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is Bell’s Palsy?

A

facial nerve paralysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is Ramsay-Hunt syndrome?

A

Varicella zoster infecting facial nerve - shingles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are distinguishing features of Ramsay hunt syndrome

A

unilateral facial droop

vesicles or rash within external ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is key when determining whether facial droop is due to stroke or facial nerve lesion?
forehead sparing - stroke - Involving motor pathways anywhere along path from primary motor cortex to where synapse with facial nerve motor nuclei Upper half of contralateral face spared (has back-up) - Involving facial nerve anywhere from from exit from brain stem And along its route to target tissue Whole half ipsilateral face
26
explain how to identify if forehead spared?
if forehead affected - no furrows, cannot raise eyebrows | if forehead spared - furrows remain and able to raise eyebrows
27
why is the forehead spared in stroke but not facial nerve lesion?
facial nerve nuclei split into top and bottom half and top half has both contralateral and back up ipsilateral innervation from PMC so if contralateral affected in a stroke then it has a back up supply so forehead spared. lower half has only contralateral supply so leads to contralateral facial droop of lower half if the facial nerve is affected after it has left brainstem, all motor elements it supplies will be affected on the ipsilateral side
28
What is CNVIII and where does it originate from?
Vestibulocochlear, from the lateral lower pons (pontomedullary junction)
29
What is the path of CNVIII
Cochlea & Semicircular canals (vestibular system) {within petrous bone} → Vestibulocochlear nerve → Internal Acoustic Meatus → lower pons
30
What type of fibres does CNVIII have?
Special sensory
31
What is the function of CNVIII?
Hearing and balance
32
How is CNVIII tested?
gross bedside hearing test (whispering 99 in each ear)* and enquiring about balance + tuning fork testing
33
how do CNVIII lesions present?
Hearing loss +/- dizziness (vertigo) +/- tinnitus
34
what are causes of CNVIII lesions?
- Vestibular schwannoma (and other posterior cranial fossa tumours) - Occlusion of labyrinthine artery - Base of skull fracture (involving petrous bone) - Brainstem lesion (pons)- rare ++
35
What is an acoustic neuroma/Vestibular schwannoma?
Benign tumour of schwann cells surrounding the vestibulocochlear nerve, compressing the nerve
36
What are the signs and symptoms of acoustic neuroma?
* Unilateral hearing loss * Tinnitus * Vertigo * Numbness, pain or weakness down one half of face (involvement of facial and trigeminal nerves )
37
Define presbyacusis.
old-age related hearing loss
38
Damage to what structures causes hearing loss?
Cochlea, cochlear component of vestibulocochlear nerve, or brainstem nucleus
39
Damage to what structures causes balance disturbance?
Semicircular canals, vestibular component of vestibulocochlear nerve, or brain nucleus
40
What do the 4 medullary cranial nerves enter after leaving the skull?
Carotid sheath, all exit at some point except vagus
41
What is CNIX and where does it originate from?
Glossopharyngeal Nerve from the lateral superior medulla
42
What is CNX and where does it originate from?
Vagus, from later upper medulla
43
describe the route of CN IX and X
Arise from medulla Run through posterior cranial fossa Exit through jugular foramen Enter into carotid sheath- close relationship with internal and external carotid arteries
44
What type of fibres does CNIX have?
General sensory, special sensory, autonomic, motor
45
What is the MAIN function of CNIX?
Sensory supply of oropharynx, posterior ⅓ tongue (SS and GS)and middle ear
46
What is the general sensation of CNIX?
* (Palatine) tonsils and oropharynx * Middle ear and tympanic membrane (medial side) * Sensory from carotid body and sinus * Pos 1/3 tongue
47
WHat is the special sensory of CNIX?
Taste of posterior 1/3 tongue
48
What is the autonomic function of CNIX?
Carries parasympathetic innervation to parotid gland
49
WHat is the motor function of CNIX?
Supplies one muscle (stylopharyngeus) which assists in swallowing
50
How is CNIX function tested?
Tested in conjunction with vagus nerve (CN X) (when asking patient to swallow)
51
What type of fibres are in CNX?
General sensory, motor and autonomic
52
What are the general sensory functions of CNX?
* Sensory to laryngopharynx, and the whole larynx | * Sensory to small part of external ear(external auditory meatus) and tympanic membrane(lateral side)
53
What is the motor function of CNX?
• Muscles of soft palate, pharynx, larynx
54
What are the autonomic functions of CNX?
Parasympathetic to thoracic (e.g. heart, tracheobronchial tree) and abdominal viscera
55
How is CNIX and X function tested?
tested together Speech, swallow, cough, soft palate movement & uvula position [CN X] [gag reflex: IX & X]
56
how is soft palate elevation tested?
get patient to say AHHH if both right and left side of soft palate innervation is intact, soft palate muscle rises equally and uvula stays in centre if vagus nerve lesion on one side, affected side soft palate won't elevate and uvula deviates away from weaker side
57
what can cause lesions of CN IX and X?
- RLN branch of CN X- (thyroid pathology or surgery; superior thorax/mediastinal pathology) - Pathology involving carotid sheath structures (e.g. common or internal carotid artery dissection/surgery) - Posterior cranial fossa tumours, base of skull #s (jugular foramen) - Brainstem (medullary) lesions e.g. infarct, MND
58
What is CNXI and where does it originate from?
Spinal accessory nerve, Posterolateral medulla
59
What is CNXII and where does it originate from?
Hypoglossal nerve, lateral to medullary pyramid
60
describe the path of CN XI and XII
* Arise from medulla (accessory nerve also has some contribution from upper cervical spinal nerves) * Run through posterior cranial fossa * CNXI exit skull through jugular foramen * CNXII exit through hypoglossal canal * Enter into carotid sheath- * Hypoglossal exits and travels towards tongue * Accessory exits and heads towards posterior triangle
61
What type of fibres are in CNXI?
Motor
62
What is the function of CNXI?
Motor to sternocleidomastoid and trapezius
63
What is the path of CNXI?
Medulla → Jugular foramen → carotid sheath → deep to SCM → posterolaterally across posterior triangle → deep to trapezius
64
How is function of CNXI tested?
* Shrug shoulders against resistance (trapezius) | * Turn head against resistance (sternocleidomastoid)
65
Where is CNXI susceptible to damage?
* Spinal accessory runs inferiorly through neck in posterior triangle (is quite superficial) * Susceptible to injury in this area e.g. in lymph node biopsies, surgery, stab wound
66
causes of CNXI lesions?
fd
67
What is the path of CNXII?
Medulla → hypoglossal canal → carotid sheath → medial to mandible angle → between carotids
68
What type of fibres are in CNXII?
Motor
69
What is the function of CNXII?
Innervates Muscles of the tongue (all except one)
70
How is CNXII function tested?
Inspection and movement of the tongue, damage to CNXII cause weakness and atrophy of tongue on ipsilateral side, tongue deviates towards damaged side
71
describe tongue protrusion test for hypogossal damage
when asked to stick tongue out, should stay in middle. if damage to hypoglossal nerve, muscle on affected side becomes weak and so tongue deviates to weaker side. tongue never lies
72
what can cause hypoglossal nerve lesions?
Inspection and movement of the tongue, damage to CNXII cause weakness and strophy of tongue on ipsilateral side, tongue deviates towards damaged side

Semester 3 - Head and neck (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions