S5 L1 Cranial Nerves 7-12 Flashcards
Which part of the ‘system’ can injuries arise?
ANYWHERE
Trigeminal nerve (CN V)
- Where does it arise
- What does it look like in dissection image?
- What are the structures around it?
Trigeminal nerve:
- 3 divisions, where do they pass through, how many branches come from them?
- Sensory distribution over the face - what is it?
Distal branches of Va, Vb, Vc of the trigeminal nerve
- Va: 2
- Vb: 2
- Vc: 4
Va division
- Route of this nerve
- Where do all the distal branches come off
- Anatomical location of the nerves
- Hutchinson’s sign - what is this? which nerve branch? what condition?
Vb division:
- Route of this nerve
- Where do all the distal branches come off
- Anatomical location of the distal nerves?
- How are these distal nerves vulnerable to injury (which injury)?
Vc division:
- Route of this nerve
- Where do all the distal branches come off
- Anatomical location of the distal nerves?
- How are these distal nerves vulnerable to injury (which injury)?
- *Facial nerve - CN VII**
- Origin
- Role (3 major)
- How to examine?
- Points of vulnerability (think about the route of the nerve -> next FC)
ORIGIN: PONTOMEDULLARY JUNCTION
Facial Nerve cont.
- Route
Facial droop: How to tell if it is a stroke or caused by facial nerve palsy?
- What does the face look like with each?
Facial droop: Full explaination of the visual signs of the face of stroke compared to facial palsy
- *CN VIII - Vestibulocochlear**
- Role
- Test/examination
- Presents can present with…
- Route of this nerve
- Points of vulnerability of this nerve…
Special sensory neurone
Points of vulnerability: Vestibular schwannoma (and other posterior cranial fossa tumours) Occlusion of labyrinthine artery (blood supply of CN VIII) Base of skull fracture (involving petrous bone) Brainstem lesion (pons) - rare\*\*
ORIGIN: PONTOMEDULLARY JUNCTION
Vestibular Schwannoma (Acoutic Neuroma)
- Symptoms and signs (and reasons for these)
- locations of it
- *CN IX (Glossopharyngeal) and CN X (Vagus)**
- Routes of these nerves
- Examined together?
- Role of CN IX
- Role of CN X
CN IX and X:
- Patients may present with…
- What to examine
- Points of vulnerability of these nerves (including RLN)
- RLN (Recurrent Laryngeal nerve) 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
How to examine soft palate muscles…
Commonality in routes for cranial nerves exiting medulla (CN IX, X, XI)
- Then what happens to these nerves…
Key branches of vagus nerve (in the neck)
CN XI, XII - Accessory and Hypoglossal
- Arise from?
- Route through base of the skull?
- Arise from medulla (accessory nerve also has some contribution from upper cervical spinal nerves)
- Run through posterior cranial fossa
- Different routes through base of the skull:
Accessory - runs through jugular Foramen
Hypoglossal - runs through the hypoglossal canal - Enter into carotid sheath:
Hypoglossal exits and travels towards tongue
Accessory exits and heads towards posterior triangle
- *CN XII Hypoglossal**
- Origin
- Role
- Points of vulnerability
- Recap on its route
Label
How to test the muscle that protrudes the tongue?
- *CN XI Spinal Accessory nerve**
- Origin
- Test
- Points of vulnerability
CN XI
- Route of nerve
- Signs of this nerve damage
Label these cranial nerves
Which nerves are from the ponstomedullary junction?
Abducens nerve, facial nerve and vestibulocochlear nerve
