Test Three Words Flashcards
LGN axons with info from superior retina.
Travel through the parietal lobe and terminate in the cuneus of the occipital lobe.
Lateral geniculate nucleus (LGN)
Where the second neurons cell bodies lie and where the optic tracts terminate. It is part of the diencephalon.the axons that start here; travel as the optic radians and terminate in the visual cortex.
LGN path from inferior retina.
Through temporal lobe to lingual gyrus of the occipital lobe
What will pituitary enlargement affect?
Press on the optic chiasm first effecting the inferior nasal fibers which cross. This will result it loss or reduced vision in the superior temporal VF bitemporally
ICA aneurism on one side
Lies lateral to the optic chiasm so could compress outer temporal fibers resulting in loss of nasal vision on the effected side
CN III ocular motor nerve emerges
From the interpeduncular fossa of the midbrain
CN III ocular motor nerve runs between which veins
Posterior cerebral artery (just anterior to CN3)
Superior cerebellar artery (just posterior)
Posterior communicating artery ( just medial to it)
CN III ocular motor nerve under what and through what
Between anterior and posterior clinoid processes of the tent proud cerebelli ( lateral)
Through the lateral wall of the cavernous sinus
To the orbit through superior orbital fissure
CN III ocular motor nerve between what brain lobe and skull part?
Temporal lobe laterally and Petrous part of the temporal bone medially
CN III ocular motor nerve functions
Motor innervation to skeletal muscles of the eye
Levator palpebrae superioris ( elevates upper eyelid), SR, MR, IR, IO
Parasympathetic motor innervation to smooth muscles: sphincter pupillae ( constricts pupil) and ciliary body muscle (accommodation)
CN III ocular motor nerve superior division
Innervates levator palpebrae superioris and superior rectus
CN III ocular motor nerve inferior division
Medial rectus, inferior rectus, inferior oblique
Vasa nervorum
Centrally located blood vessels with the nerve that supply the blood to the nerve
location of parasympathetic nerve fibers in CNIII
at the level of the midbrain- superficially superior and medially
in or near the cavernous sinus- superficially and medially
In orbit before CNIII divides into sup and inferior divisions- superficially medial and inferiorly
what happens to the position of the eye if CNIII is damaged?
lateral rectus (innervated by CN VI) and superior oblique (CN IV) take over and turn the eye down and out.
