One of a pair of motor nerves, the fourth and smallest cranial nerve, essential for eye movement.
The fourth cranial nerve (IV), which supplies the superior oblique muscle, one of the muscles responsible for movement of the eyeball in its socket. The action of the trochlear nerve is coordinated with that of the oculomotor and abducens nerves.
The fourth cranial nerve (arising from the brain), which acts upon the superior oblique muscle of the eye.
The fourth cranial nerve, a small mixed nerve arising from the midbrain. It is both sensory and motor to the superior oblique muscle of the eye.
The trochlear nerve is the fourth cranial nerve, and there are two of them originating in the brainstem, one on either side of the midbrain. These nerves pass through openings in the skull bones to reach the eye sockets. Each trochlear nerve governs one of the two superior oblique muscles, which facilitate the downward and outward rotation of the eyes.