Which of the following nerves helps in raising the upper eyelids?

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2019

Explanation

The oculomotor nerve (Cranial Nerve III) provides motor innervation to the levator palpebrae superioris muscle.
Contraction of the levator palpebrae superioris muscle is the primary action that results in the elevation (raising) of the upper eyelid.
Therefore, the oculomotor nerve is the nerve responsible for opening the eye.

Option A: The optic nerve is a purely sensory nerve responsible for transmitting visual information from the retina to the brain. It has no motor function and does not control any muscles.
Option C: The trigeminal nerve is primarily responsible for facial sensation (touch, pain, temperature) and innervating the muscles of mastication (chewing). While its ophthalmic branch provides sensation to the eyelid skin, it does not control eyelid movement.
Option D: The facial nerve controls the muscles of facial expression. It innervates the orbicularis oculi muscle, which is a sphincter muscle around the eye responsible for forcefully closing the eyelids (blinking). Its function is opposite to raising the eyelid.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Cranial nerve function related to eyelid movement as background academic context rather than a clinical decision trigger.
Assessing eyelid movement is a key part of a neurological examination. Ptosis (drooping eyelid) is a classic sign of oculomotor nerve (CN III) palsy.
Nurses must be able to differentiate the causes of ptosis. For example, ptosis from CN III palsy is often severe and may be accompanied by a dilated pupil and an eye that deviates down and out.
What if? If a patient presents with mild ptosis, a constricted pupil (miosis), and decreased sweating on one side of the face (anhidrosis), the cause is likely Horner's syndrome. This condition results from disruption of the sympathetic nerve pathway, not a CN III lesion.

How to Approach the Question

This is a factual recall question based on anatomy and physiology.
First, identify the specific action described in the question stem: "raising the upper eyelids".
Second, recall the primary muscle responsible for this action, which is the levator palpebrae superioris.
Third, recall the cranial nerve that provides motor innervation to this specific muscle.
Finally, evaluate the given options. The oculomotor nerve (CN III) innervates the levator palpebrae superioris. The other nerves have different functions: CN II is for vision, CN V is for facial sensation, and CN VII is for closing the eyelid.

Concept Tested & Keywords

Qti0QxIhf4nYAsVq3CO0rj

E6 Anatomy Applied Ashalatha 4e p. 426-428

E6 Anatomy Grays 43e Vol 2 Part 1 p. 65-67

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