Cranial nerves Flashcards
Which 2 cranial nerves originate from the cerebrum
CN I - Olfactory nerve
CN II - Optic nerve
Which CN arises from the midbrain
Trochlear nerve - CN VI
Which CN has the longest intracranial course
Trochlear nerve - CN IV
Which CN arises from the midbrain pontine junction
Oculomotor nerve - CN III
Which CN arises from the pons
Trigeminal nerve - CN V
Which CN arises from the pontine medulla junction
Abducens, facial, and vestibulocochlear (CN VI-VIII)
Which CN arise from the medulla posterior to the olive
Glossopharyngeal, vagus and accessory nerve (CN IX-XI)
Which CN arise from the medulla anterior to the olive
Hypoglossal nerve (CN XII)
A lesion in the temporal lobe would give what visual field defect
Superior homonymous quadratonopia
A lesion in the parietal lobe would give what visual field defect
Inferior homonymous quadratonopia
A pituitary adenoma compressing the optic chiasm would give which visual field defect
Bitemporal hemianopia
What are the common causes of an oculomotor nerve palsy
Raised intracranial pressure (compresses the nerve against the temporal bone)
Posterior communicating artery aneurysm
Cavernous sinus infection or trauma
What modalities does the oculomotor nerve carry
Motor
Parasympathetic
The trigeminal nerve is associated with derivatives of which pharyngeal arch
1st
Inferior alveolar nerve block is utilised when undertaking what procedures
Dental procedures
Which CN travels in Dorellos canal
Abducens nerve (CN VI)
The facial nerve is associated with derivatives of which pharyngeal arch
2nd
What are the first 3 branches of the facial nerve
Greater petrosal nerve
Nerve to stapedius
Chorda tympani
What are the terminal 5 branches of the facial nerve and where does it divide into them
Temporal, Zygomatic, Buccal, Marginal mandibular, cervical
Divides within the parotid gland
Which nerve is at risk of damage in a basal skull fracture
Vestibulocochlear nerve (CN VIII)
Which muscles of the pharynx does glossopharyngeal nerve innervate
Stylopharyngeus
The vagus nerve is associated with derivatives of which pharyngeal arches
4th and 6th
Which branches of the vagus nerve arise in the neck
Pharyngeal branches
Superior laryngeal nerve
Recurrent laryngeal nerve
How does the path of the recurrent laryngeal nerve differ on the right and left
Right recurrent laryngeal nerve - hooks under the subclavian artery
Left recurrent laryngeal nerve - hooks under the arch of the aorta
All of the muscles of the larynx are innervated by the vagus nerve except for which
Stylopharyngeus
Innervated by glossopharyngeal nerve
A unilateral recurrent laryngeal nerve lesion will cause which clinical features
Dysphonia
Bilateral recurrent laryngeal nerve lesion will cause which clinical features
Aphonia (loss of voice)
Stridor
What are the 2 muscles innervated by the spinal accessory nerve
Trapezius
Sternocleidomastoid
From which spinal segments does the accessory nerve arise from
C1-C5/C6
Why is the accessory nerve vulnerable to damage
It is found quite superficial
Runs between the investing and prevertebral layers of fascia
The long course of the abducens nerve makes it vulnerable to what
Raised ICP
