Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

H&N > Session 5: Cranial Nerves VII-XII - Origin, Route and Function > Flashcards

Session 5: Cranial Nerves VII-XII - Origin, Route and Function Flashcards

1
Q

Nerves arising from pons.

A

Trigeminal

Abducens

Facial

Vestibulocochlear

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

What is CN VII?

A

Facial nerve

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

Route of the facial nerve.

A

Arise from the pontomedullary junction.

Enter the petrous bone via the internal acoustic meatus.

In the petrous bone it gives off three branches at the geniculate ganglion:

Greater petrosal nerve, Chordae tympani, Stapedius nerve

The remaining part of the facial nerve goes out via the stylomastoid foramen and pierces through the parotid gland (does not innervate it) to give its branches to facial expression.

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

Facial nerve branches of facial expression.

A

To Zanzibar By Motor Car

Temporal

Zygomatic

Buccal

Mandibular

Cervical

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

What kind of nerve is the facial nerve?

A

Special sensory

Motor

General sensory

Autonomic

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

Function of the facial nerve.

A

Special sensory: Taste - anterior 2/3rds of the tongue

General sensory: Small area of the external ear

Motor: Muscles of expression (and scalp) + stapedius in middle ear

Autonomic (parasympathetic): Lacrimal glands, mucosal glands in nose and roof of mouth, submandibular gland, sublingual gland

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

What does the nervus intermedius of the facial nerve carry?

A

Parasympathetic and sensory fibres

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

How do you test the facial nerve?

A

Testing muscles of facial expression + corneal reflex.

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

How can lesions of the facial nerve present with different symptoms?

A

Depending on where it sits. If it sits proximal to the geniculate ganglion all branches would be affected. If it has given off its branches only muscles of facial expression would be affected etc…

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

Common symptoms of facial nerve damage.

A

Facial expression muscle palsy (Bell’s palsy), dry eyes, dry mouth, hyperacusis, altered taste

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

Give examples of how the facial nerve can be damaged.

A

Lesions

Middle ear pathology

Parotid gland pathology

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

What is the afferent nerve of the corneal reflex?

A

CN V ophthalmic division

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

What is the efferent nerve of the corneal reflex?

A

The facial nerve

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

What is the 8th cranial nerve?

A

Vestibulocochlear nerve

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

Route of the vestibulocochlear nerve.

A

Arise from the pontomedullary junction.

Go via the internal acoustic meatus to the cochlea and semicircular canals.

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

What type of nerve is the vestibulocochlear nerve?

A

Special sensory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of the vestibulocochlear nerve?

A

Hearing and balance

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

How to test the vestibulocochlear nerve.

A

Crude hearing test (whispering 99 in an ear)

Enquiry of balance

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

What would damage involving of cochlea in relation to the vestibulocochlear nerve?

A

Damage involving the coclea, cochlear component of vestibulocochlear nerve or brainstem nucleus can result in hearing loss.

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

What would happen if there is damage to the semicircular canal or vestibular component of vestibulocochlear nerve?

A

Disturbance of balance (vertigo)

This can also happen if there is damage to the brain nucleus.

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

What is an acoustic neuroma?

A

A benign tumour involving the vestibulocochlear nerve.

They are tumours of the Schwann cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What symptoms and signs can an acoustic neuroma cause?

A

Unilateral hearing loss

Tinnitus

Vertigo

Numbness, pain or weakness down one half of face.

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

Explain why you can get numbness, pain or weakness down one half of the face in an acoustic neuroma.

A

Because the facial nerve runs through the same opening as the vestibulocochlear nerve does which is the internal acoustic meatus.

If there is an acoustic neuroma it can enlarge and impinge on the facial nerve as well.

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

State the four cranial nerves arising from the medulla.

A

Cranial nerve IX Glossopharyngeal

Cranial nerve X Vagus

Cranial nerve XI Accessory

Cranial nerve XII Hypoglossal

25
Q

All the 4 cranial nerves that arise from the medulla exit the base of the skull to enter into what structure?

A

Carotid sheath

(Most quickly exit though)

26
Q

Which cranial nerve runs the length of the carotid sheath?

A

CN X Vagus nerve

27
Q

What is CN IX called?

A

Glossopharyngeal nerve

28
Q

What type of nerve is the glossopharyngeal nerve?

A

General sensation

Special sensory

Autonomic

Motor

29
Q

Explain the general sensation functions of the glossopharyngeal nerve.

A

General sensation to palatine tonsils and oropharynx.

Middle ear and tympanic membrane

Sensory from carotid body and sinus.

Gag reflex (sensory limb)

30
Q

Explain the special sensory of the glossopharyngeal nerve.

A

Taste and general sensation of the posterior 1/3 of the tongue.

31
Q

Explain the autonomic innervation of the glossopharyngeal nerve.

A

Carries parasympathetic innervation to parotid gland.

32
Q

Explain the motor function of the glossopharyngeal nerve.

A

Stylopharyngeus assisting in swallowing.

33
Q

Explain the route of the glossopharyngeal nerve.

A

Arise from the medulla.

Exits via the jugular foramen.

First gives off a branch to sensory from middle ear called the tympanic branch. Second branch to be given off is the parasympathetic to parotid gland. It then gives off branches for taste and general sensation from posterior 1/3 tongue, as well as, sensory fibres from oropharynx.

It then descends to supply the carotid sinus, and carotid bodies.

34
Q

How to test the glossopharyngeal nerve.

A

Usually tested in conjunction with the vagus nerve when asking patients to swallow.

Taste is not formally tested.

The gag reflex is only tested if concerns around swalloing and integrity of nerves involved in this reflex.

Isolated lesions of CN IX are rare.

35
Q

The sensory part of the gag reflex is carried out by the glossopharyngeal nerve. Which nerve does the motor function of the gag reflex?

A

CN X

36
Q

What is CN X called?

A

Vagus nerve

37
Q

Explain the route of the vagus nerve.

A

Arise in the medulla

Goes through the jugular foramen and into the carotid sheath.

It then descends the neck into the thorax and abdomen.

38
Q

What kind of nerve is the vagus nerve?

A

General sensory

Motor

Autonomic

39
Q

Explain the general sensory function of the vagus nerve.

A

Sensory to lower pharynx and the whole larynx.

Sensory to small part of the external ear and tympanic membrane

40
Q

Explain the motor function of the vagus nerve.

A

Muscles of soft palate, pharynx (laryngopharynx not oropharynx) and larynx.

Gag reflex

41
Q

Explain the autonomic function of the vagus nerve.

A

Parasympathetic fibres to thoracic and abdominal viscera.

42
Q

Two important branches of the vagus nerve.

A

Right and left recurrent laryngea nerve.

43
Q

What is special about the recurrent laryngeal nerves?

A

Right turns and loops around the right subclavian artery.

The left turns and loops around the arch of aorta.

44
Q

How to test vagus nerve.

A

Note the patient’s speech, cough and ability to swallow.

Note movement of uvula and soft palate when the patient says ‘Aaah’.

Gag reflex

45
Q

What can injury to the recurrent laryngeal nerve following thyroid surgery cause?

A

Hoarseness of voice and dysphonia

46
Q

What is CN XI also called?

A

Accessory nerve.

47
Q

What kind of nerve is the accessory nerve?

A

Motor

48
Q

Explain the motor function of the accessory nerve.

A

Motor function to sternocleidomastoid and trapezius.

49
Q

Explain the route of the accessory nerve.

A

Arise from the medulla. It then passes through the jugular foramen. It passes deep to SCM and provides it motor innervation to it.

The runs posterolaterally across posterior triangle.

Enters deep to trapezius and gives off its motor innervation to it.

50
Q

Since the accessory nerve runs in the posterior triangle it is quite vulnerable to damage.

What is the consequence of damage in the posterior triangle leading to damage of the accessory nerve?

A

Weakness of trapezius.

51
Q

Accessory nerve does not only supply trapezius yet in the case of damage to the accessory nerve in the posterior triangle SCM remains unaffected.

How is this possible?

A

The accessory nerve gives off its branches to the SCM prior to running into the posterior triangle.

52
Q

How to test the accessory nerve.

A

Shrug shoulders against resistance (trapezius)

Turn head against resistance (SCM)

53
Q

What is CN XII also called?

A

Hypoglossal nerve.

54
Q

What kind of nerve is hypoglossal?

A

Motor

55
Q

Explain the motor function of the hypoglossal nerve.

A

Muscles of the tongue all except one.

56
Q

Explain the route of the hypoglossal nerve.

A

Arises from the medulla.

Passes through the hypoglossal canal and then descends to run medial to angle of the mandible.

It will start by descending lateral to the internal and external carotid arteries but will then cross over laterally to medial.

It then passes inferiorly to the angle of the mandible to then enter the tongue.

57
Q

How to test the hypoglossal nerve.

A

Inspection and movement of the tongue.

58
Q

What are the consequences of damage to the hypoglossal nerve.

A

Damage to the hypoglossal nerve causes wekaness and atrophy of the tongue muscles on ipsilateral side.

59
Q
A

H&N (37 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions