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REFLEC
T
PUPIL REFLEXES
- Regulatesthesizeof the pupil
- Controlled by the SNA
• Parasympathetic SN -> produces pupillary contraction
or miosis
• Sympathetic SN -> produces dilationofthe
pupilor mydriasis
PHOTOMOTOR REFLEX AND CONSENSUS
- The pupillary contraction of the eye in which the light is projected is called
directphotomotor reflex
- Contraction of the opposite pupil, even though the light does not reach this
consensual light reflection is called 333
SYNAPSIS
- First 2 arein the visual pathway
3. pretectal nucleus
4. Parasympathetic nuclei of the oculomotor nerve
Afferent impulses travel to 5. ciliary ganglion
through the optic nerve , the chiasma and 6. iris pupil constrictor muscle
optic tract à
In this place a small number of PATHOLOGIES
fibers leave the optictractat º Sx of Adie à photomotor
establishing synapses with cells reflex absent or diminished . C
nerves of the pretectal nucleus ontraction slow or delayed vision
located near the superior colliculus (in close and slow dilation or
midbrain) to delayed night vision. Pb
Impulses are carried by axons is due to a nervous disorder
of the prerectalnervecellsto parasympathetic in M. constrictor
to the parasympathetic nucleiofthe N. of the pupil
oculomotor(Edinger nucleus -
Westphal) from both sides to º Pupil a by Argyll Robertson à pupi
Here the fibers establish synapses l small, fixed size and not
Parasympathetic nerves have a reacts to light, but contracts
route through NC III to as responses to accommodation
to the ciliary ganglion in the orbità al º Sx of Horner to consists in
end, parasympathetic fibers contraction pupillary,lightfallof the
postganglionic pass through eyelid (ptosis), enophthalmos,
short ciliary nerves dilatationofthearteriolescutaneous
reaching the eyeball and the muscle andloss ofsweating . Result
withiris pupil strictor of the loss of innervation
sympathetichead and neck.