Which cranial nerve is responsible for movement of eye ball?

Question

Question

This question was previously asked in

KGMU Nursing Officer 2023 Memory-Based Previous Year Paper

Answer 1

Correct Answer: Occulomotor

Rationale:

The oculomotor nerve (cranial nerve III) is primarily responsible for controlling most of the movements of the eyeball. It also regulates pupil constriction and maintains the position of the upper eyelid.
This nerve innervates several muscles, including the superior rectus, inferior rectus, medial rectus, and inferior oblique muscles. These muscles are critical for moving the eye in various directions.
Additionally, the oculomotor nerve has a parasympathetic function, helping in pupil constriction via the sphincter pupillae and accommodation of the lens through the ciliary muscles.

Explanation of Other Options:

Vagus (Cranial Nerve X)

Rationale: The vagus nerve is not involved in eye movement. It primarily controls autonomic functions such as heart rate, digestion, and respiratory rate. It also provides sensory input from the throat and abdomen and motor output to the throat muscles.

Trigeminal (Cranial Nerve V)

Rationale: The trigeminal nerve is a mixed nerve responsible for facial sensation and motor functions such as chewing. It does not contribute to the movement of the eyeball.

Olfactory (Cranial Nerve I)

Rationale: The olfactory nerve is solely responsible for the sense of smell. It has no role in eye movement or any motor functions.

Conclusion:

The oculomotor nerve (cranial nerve III) is the correct answer as it is directly responsible for most movements of the eyeball and additional functions such as pupil constriction. Other options, including the vagus, trigeminal, and olfactory nerves, are unrelated to eye movement and serve entirely different functions in the body.