Question

In contrast to the oculomotor nerve, the optic nerve:

A) is the second cranial nerve and provides the sense of vision.
B) carries parasympathetic nerve fibers that constrict the pupil.
C) is the third cranial nerve and regulates movement of the eyes.
D) innervates the muscles that cause motion of the upper eyelids.

Answer 1

The optic nerve is the second cranial nerve and is essential for vision, differing from the oculomotor nerve which controls eye movements and pupil constriction.

Step-by-step explanation:

Correctly distinguishing the optic nerve from the oculomotor nerve is crucial for understanding their distinct functions. The optic nerve, identified as the second cranial nerve, is responsible for providing the sense of vision. Its primary role involves transmitting visual information from the retina to the brain, enabling the perception of visual stimuli.

In contrast, the oculomotor nerve, classified as the third cranial nerve, serves a different purpose. It predominantly controls the movement of the eye muscles and contributes to pupil constriction through its parasympathetic fibers. Unlike the optic nerve, the oculomotor nerve is associated with the motor functions of the eye and does not directly participate in transmitting visual information.

Therefore, option A) correctly identifies the optic nerve as the second cranial nerve and emphasizes its role in providing the essential sense of vision without involvement in eye muscle movements or pupil constriction.