Pupillary light reflex

[purplelife]

Pupillary light reflex

F.A. says light reflex goes through CN-2-optic n. and Uworld says it goes through CN3-oculomotor to Edinger-Westphal n. Does it go through both of them?

This is what I understand so far.. Please correct me if I’m wrong.

Pupilllary light reflex

Light->retina->cilliary ganglion of Cn2(optic)->Cn3(oculomotor)?->{enters Midbrain: to bilater Edinger Westphal n.->pretectal n->optic tract->optic n.-> Bilateral pupil constriction(consensual reflex)


Thank you!

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[MLT2MT2DO]

http://ccn.aacnjournals.org/content/27/1/62/F2.large.jpg

Note, optic nerve doesn't synapse on ciliary ganglia

 

[Charles_Carmichael]

Afferent is II, efferent is III. So, you need both intact to have an appropriate response.

PS. II doesn't have a motor component. It's sensory only. Review your cranial nerves if you're having issues keeping sensory vs. motor vs. both straight. FA has a decent mnemonic for it if you need it. Hope that helps.

 

[purplelife]

Thank you both of you for clarifying! That link really helped me understand it better. I'm gonna draw it out a couple times so I remember it forever. Thank you again!