Peripheral distribution of cranial nerves II Flashcards Preview

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Flashcards in Peripheral distribution of cranial nerves II Deck (44)
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1
Q

what are the fibres of the facial nerve

A
  • branchiomotor efferent
  • general visceral efferent
  • special sensory afferent
  • general somatic afferent
    It is associated with the pharyngeal arch number 2 instead of the myotomes
2
Q

what do these parts of the facial nerve innervate?

  • branchiomotor efferent
  • general visceral efferent
  • special sensory afferent
  • general somatic afferent
A

BE: muscles of facial expression, post digastric, stylohyoid & stapedius

GVE: parasympathetic- lacrimal, submandibular and sublingual glands, mucus membranes of nasopharynx

SA: Taste from anterior 2/3 tongue (chorda tympani) and palates ( also have taste buds in the palate)

GSA: Very minor role. Skin of part of external ear and behind (travel with branchiomotor- post auricular)

3
Q

describe the pathway of the facial nerve

A
  • everything apart from the branchiomotor efferent, they all lump together in one big collection called nervous intermedius (the motor compotent is separate from the rest)
  • it passes through the internal acoustic meatus and then it goes through the facial canal
4
Q

describe the parasympathetic supply of the facial nerve

A
  • 50% of the paraysmtpetic supply comes of from the greater petrosal nerve
  • this is joined by the deep petrosal nerve - this is a sympathetic nerve
  • the other 50% of the parasympathetic supply - it goes to the tongue and forms the chorda tympani ( this is the special sensory nerve )
  • the Chorda tympani is joined by the linguinal nerve which comes from V3
5
Q

what does the greater petrosal nerve innervate

A

the mucus gland and lacrimal glands

6
Q

what are the motor branches of the facial nerve

A

Temporal

Zygomatic

Buccal

Marginal Mandibular

Cervical

7
Q

what does the corda tympani innervate

A

Taste to anterior 2/3 of tongue

Parasympathetic supply to sublingal and submandibular glands

8
Q

the facial nerve goes through ..

A

the parotid gland but does not innervate it

9
Q

the facial nerve from the brainstem to the cranial and extracrnaillay to the skeletal muscle is

A

the lower motor neurone

10
Q

the facial nerve going from the cortex to the brainstem is

A

the upper motor neurone

11
Q

what are the lower motor neurones lesions of the facial nerve

A

Ipsilateral paralysis of upper AND lower face
• Cornea at risk of drying out/hyperacusis/loss of taste (ant 2/3rd of tongue) as these are innervated by the facial nerve

Causes include: Bell’s Palsy, viruses such as
Herpes, sarcoid

12
Q

what are the upper motor neurone lesions of the facial nerve

A

Contralateral paralysis of lower face

Forehead sparing due to bilateral innervation
of facial nucleus - therefore people can still frown due to dual innervation from both sides of the brain

Usually caused by Stroke

13
Q

What are the nerve fibres of the vesbulocochlear nerve

A
  • special sensory afferent

- purely sensory nerve

14
Q

what is the vestbulochoclear nerve divided into

A
  • Cochlear branch

- Vestibular branch

15
Q

what do the 2 parts of the vestbulocochlear CNVIII do and what is there pathway

A
  • Cochlear branch from organ of Corti to cochlear nuclei on inferior cerebellar peduncle (hearing) - it picks up the mgantidue of sound waves
  • Vestibular branch from vestibular apparatus to vestibular nuclei at pontomedullary junction (balance) - is helps us orientate the position of head to gravity
16
Q

what is the tympanic membrane

A

bounce of the tympanic membrane and this starts vibrating the bones ossicles in the middle ear – malleus, incus and stapes

17
Q

what happens if the stapes is paralysed

A
  • if the stapes is paralysed causes hypersenstiivey to sound
18
Q

what is the middle ear made out of

A

– malleus, incus and stapes

19
Q

what are the fibres of glossopharygenal CN IX

A
Branchiomotor Efferent (BE3), 
General Visceral Efferent (GVE)
Special Sensory Afferent (SA), 
General Visceral Afferent (GVA)	 
General Sensory Afferent (GSA)
origins in the third phagrgenal arch
20
Q

what do the fibres of the glossopharyngeal innervate

Special Sensory Afferent (SA), 
General Visceral Afferent (GVA)
General Sensory Afferent (GSA)
General Visceral Efferent (GVE)
Branchiomotor Efferent (BE3),
A
  • SA: special taste to posterior 1/3rd of tongue
  • GVA: Oropharynx (“gag”), carotid bodies (O2) & carotid sinus (BP), general sensation post 1/3rd of tongue
  • GSA: auricle, ext. acoustic meatus, mid ear & eustachian tube
  • GVE: parasympathetic to parotid gland (otic ganglion)
  • BE: stylopharyngeus muscle
21
Q

what are the fibres of the vagus nerve

A
  • Branchiomotor Efferent (BE),
  • General Visceral Efferent (GVE)
  • General Somatic Afferent (GSA),
  • General Visceral Afferent (GVA
  • origins in 4th pharyngeal arch
22
Q

what do the fibres of the vagus nerve innervate

  • Branchiomotor Efferent (BE),
  • General Visceral Efferent (GVE)
  • General Somatic Afferent (GSA),
  • General Visceral Afferent (GVA
A

BE: pharynx, larynx & soft palate (swallowing & phonation)
GVE: parasympathetic to thoracic and abdominal viscera
GSA: sensory from upper pharynx and larynx
GVA: sensory information from lower pharynx and larynx, abdominal and thoracic viscera; stretch receptors aortic arch, chemoreceptors and aortic bodies

23
Q

what are the branches of the vagus nerve in the neck

A

pharyngeal branches - these go to the pharynx and the soft palate

superior laryngeal nerve

internal laryngeal – sensory GSA to larynx above vocal folds

external laryngeal nerve – motor BE to cricothyroid muscle

recurrent laryngeal nerve – motor BE to all other intrinsic muscles of larynx and sensory GVA to area below vocal folds

24
Q

what is the pathway of the vagus nerve in the head

A

• In the head:
– Auricular nerve
• external acoustic meatus and tympanic membrane (GSA)
• Exits skull - jugular foramen
• Descends in neck in carotid sheath between the IJV and ICA

25
Q

what is the pathway of the vagus nerve in the neck

A

– Pharyngeal nerves – pharyngeal plexus
– Superior laryngeal nerve – descends on lateral wall of pharynx
– Right recurrent laryngeal nerve – loops under RSCA
– Left recurrent laryngeal – loops under the aortic arch
– Cardiac branches arise

26
Q

what is the pathway of the vagus nerve in the thorax

A

– Cardiac branches to superficial cardiac plexus (aortic arch) & deep cardiac plexus (carina)
– Posterior (R) and anterior (L) vagal trunks - oesophageal plexus

27
Q

what is the pathway of the vagus nerve in the abdomen

A

– Vagal trunks enter abdomen (oesophageal hiatus), GI tract (to splenic flexure)

28
Q

what are the fibres of the spinal Accessory nerve

A
  • branchiomotor efferent BE – from the brainstem
29
Q

where does the spinal accessory nerve originate from (spinal level)

A
  • originates from C1-C5
30
Q

describe the pathway of the spinal accessory nerve CNXI

A
  • they ascend up through foramen magnum and is joined by the cranial root, joined with the cranial root tamphyni, go through the jugular foramen and then the roots separate, the spinal root separates from the cranial root
31
Q

what are the parts of the spinal accessory nerve CNXI

A
  • spinal roots

- cranial part

32
Q

what does the spinal part of the spinal accessory nerve innervate

A
  • Spinal part innervates SCM & trapezius – motor supply
33
Q

what does the cranial part innervate

A
  • it combines with the vagus
34
Q

what happens if you damage the spinal accessory nerve

A
  • weak shrugging shoulder
35
Q

what can cause spinal accessory nerve damage

A

injury e.g during a lymph node biopsy or putting a central line in

36
Q

what are the fibres of the Hypoglossal CNXII

A
  • general somatic efferent - motor nerve only
37
Q

what does the hypoglossal nerve Innervate CNXII

A

All muscles of tonuge except palatoglossus (CNX) (this is innervated by the vagus)

38
Q

describe the pathway of the hypoglossal nerve

A
  • Rootlets from medulla and exits through the hypoglossal canal and goes to the extrinsic and intrinsic muscles of the tongue
  • Joined by C1/C2 spinal nerves which “hitch” a lift to infrahyoid muscles
  • Pass over carotid arteries medial to angle of mandible
39
Q

what happens if you damage the hypoglossal nerve

A

Ipsilateral- tongue deviates on the the same side as the lesion

Tongue deviates Towards lesion

40
Q

describe what causes the uvula to deviate

A
  • when the ulvula deviates it is a contralateral deviation – what ever way the ulvula is facing it is the opposite side that is the nerve effected
41
Q

what are the sympathetic supply to the head

A
  • 3 cervical sympathetic ganglia
    – superior, middle and inferior
    – they are inferior to the skull base
42
Q

describe how the sympathetic supply gets to the head

A
  • starts in the throax with the symaptehtic chain
  • in order for the sympathetic nerves to go from the throax to the structures above they need to ascend up into the head and neck and they converge onto the ganglia
  • from here they will send up the post ganglionic fibres to the organs
  • the post synaptic fibres travel with the internal cartoid artery
43
Q

how do the parasympathetic supply get to the head and neck

A
  • the post synaptic fibres travel with the trigeminal nerve branches to the target organs
44
Q

what is the ganglion, Trigemina branch and target of

  • CNIII - oculomotor nerve
  • CNVII - facial
  • CNVII - Facial
  • CNIX - glossophargneal
A
  • ciliary, ophthalmic, intrinsic eye muscles
  • pterygopalatine, maxillary, lacrimal gland, nasal cavity
  • submandibular, mandibular, submandibular and sublingual glands
  • optic, mandibular, parotid gland