Which of the following nerve serve as the afferent pathway for light pupillary reflex?
Afferent limb of pupillary reflex arises in the ganglion cells of the retina that send their axons into the optic nerve, optic chiasm and optic tract. Some axons from optic tract pass to the pretectal region in the midbrain, from there impulses are sent to Edinger Westphal nucleus of both eyes. Impulses from these nuclei travel in the oculomotor nerve to reach the ciliary ganglia. From the ciliary ganglia impulses travel to the eye where they cause the pupils to constrict by activation of the constrictor pupillae muscle. Pupillary light reflex refers to constriction of pupils of both eye when light is shone into the pupil of an eye. Constriction of the pupil in the eye into which light is shining is called direct response and constriction of the opposite pupil is called consensual response. Ref: Diabetes: Best Practice & Research Compendium edited by Anthony H. Barnett page 51.
Trigeminal nerve
Optic nerve
Abducent nerve
Ciliary nerve