Ventral branch

The ventral branch is the larger of the two branches of the oculomotor nerve. It joins the dorsal surface of the ventral rectus muscle before dividing into three terminations.

One innervates the medial rectus muscle, which it joins by passing ventrally to the optic nerve. Another terminates in the ventral rectus muscle. The longest passes between the gap separating the ventral and lateral rectus muscles, reaching the ventral oblique muscle, which it approaches via its caudal edge. Before its division, this ventral branch also gives rise to the oculomotor root of the ciliary ganglion, which constitutes its parasympathetic root and is made up of one or more fine branches.