Dr. Carrera-Justiz's lecture

Question 1

pathway for PLR (afferent)

Answer 1

afferent: photoreceptors in retina>CN II>optic chiasm (50-90% deccussation)>optic tract>pretectal nucleus (20% fibers)

Question 2

pathway for PLR (efferent)

Answer 2

efferent: preganglionic fibers in PS nucleus of CN II; PS fibers of CN III>ciliary ganglion>short ciliary nerve>iris sphincter muscle

Question 3

pathway for vision

Answer 3

RGC axons become CN II>optic chiasm (+/- deccussation)>lateral geniculate nucleus (synapse)>optic radiations>occipital cortex (broadmann’s areas 17-19)