Which cranial nerve is responsible for muscle control of the eye and pupil constriction?

The cranial nerve responsible for muscle control of the eye and pupil constriction is the oculomotor nerve, which is cranial nerve III. This nerve plays a crucial role in the movement of most of the eye muscles, allowing for various eye movements such as looking up, down, and inward. Additionally, it controls the muscles responsible for pupil constriction through the parasympathetic fibers. When exposed to bright light, the oculomotor nerve facilitates the constriction of the pupils to protect the retina and improve vision clarity.

In contrast, other cranial nerves listed do not perform these functions. The trigeminal nerve primarily handles sensory information from the face and motor control for chewing. The facial nerve is mainly involved in facial expression muscles and taste sensations. The abducens nerve is solely responsible for lateral eye movement, specifically controlling the lateral rectus muscle, and does not influence pupil size or control multiple eye muscles. Understanding these specific roles emphasizes the unique function of the oculomotor nerve in eye movement and pupil response.