pupillary reflex pathways

Question 1

primary visual/geniculostriate pathway

Answer 1

REtina-> LGN (via optic tract)

LGN-> primary visual cortex (via optic radiations of meyers loops)

Question 2

eye movement pathway

Answer 2

Retina-> superior colliculus -> pulvinar -> parietooccipital cortex-> CN nuclei of extraocular muscles (visual attention)

Question 3

Pupillary reflex

Answer 3

Direct and consensual light reflex (parasympathetic)
Accommodation (parasympathetic)
Pupil dialation (sympathetics)

Question 4

Direct and consensual light reflex

Answer 4

afferent limb (CN2) retinal ganglion cells (bilateral)->
Central pathway (midbrain) (pre tectal areas bilateral)->
Efferent limb (CN3) - Edinger westphal nucleus to ciliary ganglia to sphincter pupillae

anatomy of oculomotor nucleus: parasympathetics located peripherally in nerve (compression lesions)
ischemic lesions (blood vessels in middle) spare the parasympathetics

Question 5

CN reflexes for death and coma

Answer 5

corneal reflex: CN 5 (sensory), CN 7 motor
Pupillary light reflex: dialated pupils= midbrain lesion
vestibuloocular reflex look to the sound

Question 6

accommodation reflex

Answer 6

3 components near triad
Pupil constriction (sphincter pupillae M contract)
Lens accommodation (ciliary m contract)
medial rectus eyes converge

afferent limb: perception of object by visual cortex Retinal ganglion cells (bilateral -> LGN via optic radiations-> V1-> visual association cortices

Efferent to EW_. changes lens shape and pupil constriction +oculomotor
oculomotor->convergence of eyes

Question 7

argyll robertson pupil

Answer 7

accommodation reflex present

Pupillary Reflex absent

Question 8

pupillary dilation reflex

Answer 8

afferent: perception of object by visual cortex-> hypothalamus
efferent: autonomic regulatory nuclei in hypothalamus lat horn sp cd. Superior cervical ganglion, internal carotid nerve plexus, long and short ciliary nn, dialator pupillae m

Question 9

horners syndrome

Answer 9

messed up sympathetics
miosis, ptosis, anhidrosis erythematosis

anisocoria=pupil asymmetry

Question 10

pupillary light reflex

Answer 10

Retina (CN2)-> Pretectal nuclei-> EW nucleus-> sphincter

s;lide 20