'8th' cranial nerve affects?

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Explanation

The 8th cranial nerve is the vestibulocochlear nerve.
This nerve has two distinct branches: the vestibular nerve and the cochlear nerve.
The vestibular branch is crucial for transmitting signals from the inner ear's vestibular apparatus to the brain, which governs the body's sense of balance and spatial orientation (equilibrium).
The cochlear branch is responsible for transmitting auditory signals, enabling the sense of hearing.
Therefore, any condition affecting the 8th cranial nerve can directly impair a person's equilibrium.

Option A: The sense of taste is not a function of the 8th cranial nerve.
Option B: The general sensation of touch, particularly on the face, is not mediated by the 8th cranial nerve.
Option C: The sense of smell is the specific function of the 1st cranial nerve, not the 8th.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Function of the 8th Cranial Nerve (Vestibulocochlear Nerve) as background academic context rather than a clinical decision trigger.
Nurses perform basic assessments of the 8th cranial nerve by testing hearing (e.g., whisper test) and balance (e.g., Romberg test).
Damage to CN VIII can result from acoustic neuromas (tumors), infections, or exposure to ototoxic drugs like aminoglycoside antibiotics (gentamicin) and loop diuretics (furosemide). Symptoms include vertigo, dizziness, tinnitus (ringing in the ears), and hearing loss.
What if? If a patient receiving gentamicin reports sudden dizziness and ringing in their ears, the nurse must recognize these as signs of potential ototoxicity (damage to CN VIII). The immediate nursing action is to withhold the medication and promptly notify the prescribing physician for further orders.

How to Approach the Question

This is a factual recall question that tests your knowledge of neuroanatomy.
First, identify the specific nerve mentioned in the question: the 8th cranial nerve.
Recall the name and function of this nerve. The 8th cranial nerve is the Vestibulocochlear nerve.
Break down the name into its functional parts: 'Vestibulo-' refers to the vestibular system (balance/equilibrium), and '-cochlear' refers to the cochlea (hearing).
Scan the options to find a function that matches either hearing or equilibrium.
The option 'Equilibrium' directly corresponds to the function of the vestibular part of the 8th cranial nerve.

Concept Tested & Keywords

QYQYNfOqFAfsCl628vo3dD

E6 Anatomy Applied Ashalatha 4e p. 233-235

E6 Medicine Harrison 22e Part 1 p. 280-282

Practise the full RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Attempt every question from this paper in a timed mock, then review the full solution for each one.