Head and Neck
Dilator pupillae is supplied by (AIPG -2012)
|B||Sympathetic fibers from the fronto-orbital branch of trigeminal nerve|
|C||Postganglionic sympathetic fibers from cervical sympathetic chain|
|D||Postganglionic parasympathetic fibers|
1. T-1 sympathetic (pre-ganglionic) fibers arising from the of thoracic spinal cord (lateral horns) ascend up the sympathetic chain to synapse in the superior cervical ganglion.
2. Superior cervical ganglion sends post-ganglionic fibers to reach the muscle dilator pupillae in the eyeball.
3. These post-ganglionic fibers make sympathetic plexus around the carotid artery branches and then reach the ciliary ganglion in the orbit. The next course is passing along the long ciliary nerves to reach the dilator pupillae muscle.
4. Sympathetic fibers to dilator pupillae are carried by the long ciliary nerves, which are branches of nasociliary nerve (trigeminal nerve)