Week 2 - Neurology Flashcards
A positive menace response requires an intact
Facial nerve and Cerebellum (ipsilateral).
Present from 10-12 weeks.
How do the pathways for PLR and the Menace response differ?
Menace response axons reach conscious level after synapsing with lateral geniculate nucleus . Axons involved with PLR do not reach conscious level
Cranial nerve III innervates
Occulomotor nerve
Dorsal, ventral and media recti extraoccular muscles and ventral oblique.
Also plays role in efferent arm of PLR and eyelid movement
Which nerves does the Vestibulococular nerve test? (4 nerves)
Afferent: Vestibulo-ocular reflex (CN VIII)
Efferent: CN III, IV, VI
An ability to move the eye dorsoventrally would be indicative of damage to which CN?
CN III, Oculomotor nerve is required to move the eye dorsal, ventral and medially.
If the eye cannot be rotated dorsoventrally = CN III damage
What muscle in the eye does CN IV, Troclear nerve innervate?
CN IV innervates the dorso-oblique muscle which allows for inward rotation of the eye
Which nerve is responsible for the sensory innervation to the face and the cornea?
CN V, Trigeminal
Afferent/ Efferent nerves for the Palpebral reflex
Afferent: CN V, Trigeminal
Efferent: CN VII, Facial
Blink reflex elicited by touching the medial/ lateral canthus of the eye.
Which branch of CN V provides sensory innervation to a) Cornea b) Medial canthus c) Lateral canthys
CN V= Trigeminal
Ophthalmic branch provides innervation to medial canthus and cornea. (+ skin on dorsum of the nose)
Maxillary branch innervates the lateral canthus.
Trochlear nerve
CN IV innervates DO, Dorsal Oblique.
Required for inward rotation of the eyeball
Which ocular muscles does the adcucent nerve innervate (CN VI)
cn vi - ABDUCENT innervates the lateral rectus and retractor bulbi muscles
Pathway for palpebral reflex
SUBCORTICAL!
V-> Brainstem -> VII
Pathway for corneal reflex
V-> Brainstem -> VII
