- lateral horn spinal seg. T1-T3, white communicating ramus to Sympathetic Trunk ascend to Superior Cerv. Ganglion (N124)
- at Sup. Cerv. Ganglion, PRE-Gang. Symp. SYNAPSE with POST-gangl. Symp.
- POST-g. Symp. via Carotid Nerve to Carotid Plexus
- branches from Carotid Plex. to Nasociliary N.
- then to 2 LONG (posterior) CILIARY Nerves that pierce Sclera on either side of optic N. and INNERVATE
- alt. route: axons leave Nasociliary N. via Sensory Root Ganglion, pass trough ganglion to GLOBE via SHORT
- lateral horn > symp trunk > sup. cerv. gang. > cartid N >Carotid plex. > Nasociliary n. > 2 Long Cil.>
pierce sclera to CONTRACT DILATOR PUPILLAE
- notes: symp. stimulation CONTRACTS DILATOR PUPILLAE > DILATES the PUPIL
- also innverv. Tarsal (Mueller's Muscle) - see notes 00235
(2) PARA- Sympathetic
- dervived from EDINGER - WESTPHAL nucleus
- Pregang PANS travel with CN III
- leave CN III via Motor Root of Ciliary Gang. (N82)
- enter Ciliary Gang. where they SYNAPSE
- POST-gang. PANS leave via Short Ciliary Nerves which pierce sclera
- travel to Ciliary Body and either....
(1) SYNAPSE upon CILIARY MUSCLE
(2) enter IRIS to SYNAPSE on SPHINCTER PUPILLAE MUSCLE
- note: there is ALSO sensory root to the Ciliary Gang.
- LIGHT REFLEX: Parasymp. stimulation (light shined into eye) CONTACTS pupils (via Sphincter Pupilllae Muscles)
- Accomodation - Convergence Reflex: when object moved towards eyes....
(1) pupils constrict