NCIt definition : One of the extraoculomotor muscles, which arises from a common tendinous ring in the
posterior portion of the orbit, inserts on the upper part of the sclera, is innervated
by CN III, and functions to elevate, adduct, and medially rotate the eye.;
Alternative definition : CDISC: A muscle of the eye, in general extending from the annulus of Zinn to the dorsal
aspect of the eye at the annulus tendineus; primary function is depression of the
eyeball.;