sphincter pupillae

Introduction

A ring of smooth muscle surrounding the pupillary border of the iris.

Innervation

• parasympathetic
  • preganglionic fibers
    • cell bodies in Edinger-Westphal nucleus
    • fibers carried by oculomotor nerve (CN III)
• postganglionic fibers
  • cell bodies in ciliary ganglion
  • fibers carried by short ciliary nerves

More general terms

• smooth muscle (unstriated/unstriped/visceral muscle)
• sphincter