cranial 3 Flashcards
How many extraocular muscles do we have
six
how many pairs do we have to innervate
3
what is the oculomotor nerve classified as
somatic motor and visceral control
The lesion can affect the
eye movement down inferiorly and laterally
Whatdoes the somatic motor innervate
levator palpebrae superioris (superior eyelid)
superior, inferior, medial rectus & inferior oblique
The visceral motor causes
constriction of light (light response) which is controlled by the parasympathetic ganglion = innervating sphinter pupillae and ciliary muscles
Where is the CNS nucleus for the visceral motor
Edinger Westphald (midbrain region)
Lesion can cause
dilated pipil, ptosis, loss pupillary reflex
What are the functions for the Edinger Westphald
Accommodation & dilation
What is accommodation
constriction of pupils as the object is going from distant to closeup
Explain accommodation process
- Medial rectus contracts - converges
- Pupullary convergence
- Ciliary muscle contractions = lens thickness
What is the foramen for the 3rd cranial nerve
superior orbital fissure
What is the 4th nerve
Trochlear nerve
What is the only cranial nerve to originate from dorsal side
trochlear
What is the trochlear’s main function
innervates superior oblique (extraocular muscle) (GSE - general somatic efferent)
