TROCHLEAR NERVE ANATOMYThere is a very tiny mixed nerve that can be found protruding from a nucleus housed within the midbrain. If you trace it through the orbital fissure of the orbit, you can trace it all the way back to the nucleus from which it extends. This small nerve is known as the trochlear nerve.
TROCHLEAR NERVE STRUCTUREIts job is to innervate the superior oblique muscle of the eyeball. Delivering both motor and sensory nerve fibers, it offers the eyeball two more directional options. Motor impulses can cause either a downward motion or and the downward motion away from the midline.
The sensory innervation allows the eyeball to send off signals from the proprioceptors that communicate its location and its rate of activity.
Should the trochlear nerve suffer from damage, the eyeball loses its ability to move in the direction offered by this nerve, however there is no sight damage associated with damage to this nerve.
TROCHLEAR NERVE DIAGRAM
Image: Trochlear Nerve