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Neuro5
WVSOM -- CN III, IV, VI
Question | Answer |
---|---|
What two nuclei are associated with CN III? | oculomotor and edinger-westphal nucleus |
What nucleus is associated with CN IV? | trochlear nuclus |
What nucleus is associated with CN VI? | abducens nucleus |
What is the pretectal area? | deep in the midbrain. Involved in the reflex for the pupil ot contrict |
What is edinger westfall nucleus? | Preganglionic parasympathetics |
What are the two pathways of CN III? | control size of pupil and one for lens accommodation and convergence |
Where do nerves travel after the 2nd order neurons synaps in the pretectal area? | bilaterally to the edinger-westphal nucleus which projects to the ciliary ganglion which then project to the papillae muscle |
Why do both pupils constrict when you shine a light in one eye? | because both left and right pretectal areas project bilaterally to initiate the reflex to both eyes |
How does lens accommodation work? | Neurons in the visual cortex will project axons to the pretectal area and then the pretecgtal area projects axons to the oculomotor and edingerwestphal nucleus |
How does the edinger-westphal nucleus work with lens accommodation? | Projects to the ciliary ganglion which causes contraction of the ciliary muscles to adjust tension on the lens |
How does the oculomotor nucleus work for lens accommodation? | contraction of medial recti muscles causing convergence |
How does horizontal eye movement work? | The abducens nuclei will project 2 paths…one to the contralateral side which will go thru the ocularmotor nuclei that will inhibit medial movement and one straight to the lateral rectus so that the eyes move together. The same is for the opposite side. |
What is the medial longitudinal fasciulus? | it is the tunnel that connects the abducens with the oculomotor nuclei |
What is theparapontine reticular nucleus | coordinates horizontal eye movements |