Session 4 & 5 - Cranial Nerves Flashcards
What is the position of the eye in a CN IV lesion?
Upwards and inwards
What cranial nerve comes from the back of the midbrain?
CN VI - Trochlear nerve
What are the distal branches of Va?
- Frontal nerve –> Supraorbital & Supratrochlear nerve
- Nasociliary nerve (Hutchinson’s sign)
- Lacrimal nerve
What are the distal branches of Vb?
- Infraorbital nerve
- Superior alveolar nerves
What are the distal branches of Vc?
- Nerves to Muscles of mastication
- Lingual nerve (general sensory for ant 2/3 tongue)
- Inferior alveolar nerve –> Mental nerve
- Auriculotemporal nerve
What nerve comes from the bottom of the Pons
CN VI - Abducens nerve
Where does the CN VIII come out of from the brainstem?
Pontomedullary junction
Describe the route of CN VIII.
- Comes out of the Pontomedullary junction
- Moves into the Petrous bone via the Internal acoustic meatus
- Goes on to supply the inner ear organs - Cochlear & Vestibular apparatus
What are the 5 functions of the Glossopharyngeal nerve?
- sensory to oropharynx/tonsils
- posterior 1/3 tongue (SS/GS)
- parasympathetic to parotid gland
- motor to stylopharyngeus (swallowing muscle)
- afferents from carotid body & sinus
Describe the Gag reflex.
- Touching oropharynx
- Sensed by CN IX
- Impulse goes to medulla
- Motor neurons of CN X
- Pharyngeal muscles constrict
How do you check for CN X - Vagus nerve function?
- Check for uvula deviation
- Shows which side of the soft palate is paralysed
Describe the route of CN IX & CN X.
- Arise from the medulla
- move through the posterior cranial fossa
- exit via the jugular foramen
- enter the carotid sheath, then exit early after enterring
What hole does CN XI exit the skull through?
Jugular foramen
- just like CN IX and CN X
What hole does CN XII exit the skull through?
Hypoglossal canal
Which muscles of the tongue does CN XII supply?
Styloglossus
Hyoglossus
Genioglossus
Palatoglossus (innervated by CNX)
