🧠 Testing the Trigeminal Nerve (CN V)

Let’s understand this in a very simple way.

What is the trigeminal nerve?
The trigeminal nerve is the 5th cranial nerve (CN V).

It is responsible for:

• Sensation of the face
• Movements of chewing muscles

How is the trigeminal nerve tested?

✅ Correct Answer: (a) Elevation and Lowering of Jaw

Why?
The trigeminal nerve supplies the muscles of mastication (chewing).

👉 To test its motor function, the nurse asks the patient to:

• Open and close the mouth
• Elevate and lower the jaw
• Clench the teeth

Weakness or deviation of the jaw may indicate trigeminal nerve injury.

Why other options are not correct?

• (b) Inability to tense the jaw → ❌ This is a possible finding, not the test itself
• (c) Blinking of eye → ❌ Mainly involves facial nerve (CN VII)
• (d) Corneal reflex → ❌ Tests sensory CN V and motor CN VII together, not the primary motor test

Simple Exam Trick:
Trigeminal nerve = Chewing muscles → Test by moving the jaw up and down

📌 Disclaimer: For exam preparation only. Follow neurological assessment guidelines in clinical practice.

💚 Exam Objective Nursing – Asha D
Concept clarity • Easy recall • Nursing success