Bell's palsy is a disorder of?

IGNOU PB Bsc Nsg Entrance-2017

Medical & Surgical Nursing

Easy

Appeared in: IGNOU PB Bsc Nsg Entrance-2017

Explanation

Bell's palsy is defined as an idiopathic, acute, unilateral paralysis of the facial muscles.
The facial muscles are innervated by the Facial Nerve, which is the seventh cranial nerve (CN VII).
The condition arises from inflammation and compression of CN VII within the facial canal.
Symptoms directly correspond to the functions of CN VII, including facial drooping, inability to close the eye, and altered taste.

Option A: Cranial nerve IV, the Trochlear nerve, is a motor nerve that controls the superior oblique muscle of the eye. A lesion here causes difficulty looking down and inwards, resulting in vertical double vision (diplopia), not facial paralysis.
Option C: Cranial nerve IX, the Glossopharyngeal nerve, is involved in swallowing, the gag reflex, and taste from the posterior third of the tongue. Damage to this nerve leads to dysphagia (difficulty swallowing) and loss of the gag reflex.
Option D: Cranial nerve X, the Vagus nerve, has extensive functions, including roles in swallowing, speech (phonation), and parasympathetic control of thoracic and abdominal organs. A lesion can cause hoarseness, dysphagia, and deviation of the uvula away from the affected side.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Bell's Palsy and associated cranial nerve as background academic context rather than a clinical decision trigger.
The primary nursing concern in Bell's palsy is protecting the affected eye from injury. Since the patient cannot blink or close the eyelid, the cornea can become dry, ulcerated, or infected. Meticulous eye care is a critical patient-safety intervention.
Patient education is key. Nurses must teach the patient and family about eye care, strategies for eating and drinking, and facial exercises to aid recovery.
What if? If a patient with facial palsy also has a vesicular rash in the ear canal, the diagnosis is likely Ramsay Hunt syndrome (herpes zoster oticus) rather than idiopathic Bell's palsy. This requires antiviral treatment in addition to supportive care.

How to Approach the Question

First, identify the key term in the question: 'Bell's palsy'.
Recall the definition and primary characteristic of Bell's palsy, which is unilateral facial paralysis.
Next, consider the functions of the cranial nerves listed in the options.
Match the primary symptom (facial paralysis) with the cranial nerve responsible for innervating the muscles of facial expression.
Cranial Nerve VII (Facial Nerve) is the nerve that controls these muscles. Therefore, a disorder of this nerve causes the signs of Bell's palsy.
Eliminate the other options by recalling their primary functions (IV: eye movement, IX: swallowing/gag, X: voice/viscera).

Concept Tested & Keywords

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