Which cranial nerve is associated with eye movement and pupil constriction?

The cranial nerve associated with eye movement and pupil constriction is the oculomotor nerve. This nerve is primarily responsible for controlling most of the eye's movements, including the elevation of the eyelid and the movement of the eyeball in various directions. It innervates several extraocular muscles, allowing for coordinated movement necessary for activities such as tracking objects and maintaining the visual field.

Additionally, the oculomotor nerve plays a crucial role in controlling the constriction of the pupil. This function is vital for regulating the amount of light that enters the eye, thereby ensuring optimal visual acuity under varying light conditions. The constriction of the pupil happens through the sphincter pupillae muscle, which is innervated by this nerve.

In contrast, the olfactory nerve is solely responsible for the sense of smell, and does not play any role in eye movements or pupil function. The optic nerve is primarily concerned with vision and transmitting visual information from the retina to the brain, but does not control eye movement or pupil constriction. Lastly, the trigeminal nerve is involved with sensations in the face and motor functions such as biting and chewing, and does not have any connection to eye movement or pupil control. Thus, the o