Final answer:
The Trochlear nerve, or CN IV, is the fourth cranial nerve responsible for controlling the superior oblique muscle of the eye, which contributes to the intorsion and precise movement of the eye.
Step-by-step explanation:
The Trochlear nerve, also known as CN IV, is the fourth cranial nerve and is primarily responsible for the motor function of the superior oblique muscle, which is one of the extraocular muscles.
The superior oblique muscle is involved in rotating the eye along its axis in the orbit medially, also known as intorsion. This intorsion is a component of focusing the eyes on an object close to the face. By innervating the superior oblique muscle, the Trochlear nerve plays a critical role in coordinated, precise eye movements and is essential for maintaining proper vision alignment and gaze stabilization, particularly during head movements.