Corneal reflex:
should also be examined as the sensory supply to the cornea is from V nerve. Do this by lightly touching the cornea with the cotton wool. This should cause the patient to shut their eyelid.
The corneal blink reflex is caused by a loop between the trigeminal sensory nerves and the facial motor (VII) nerve innervation of the orbicularis oculi muscles.
Trigeminal Nerve (CN-V light touch sensation)
The Trigeminal nerve (CN V) is involved in sensory supply to the face and motor supply to the muscles of mastication. There are 3 sensory branches of the trigeminalnerve: ophthalmic, maxillary and mandibular
- Initially test the sensory branches by lightly touching the face with a piece of cotton wool followed by a blunt pin in three places on each side of the face:
CLINICAL EXAMINATION OF THE CNS: V NERVE MUSCLES OF MASTICATION
Motor Supply
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To test the motor supply, ask the patient to clench their teeth together, observing and feeling the bulk of the masseter and temporalis muscles
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Ask the patient to then open their mouth against resistance.
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Finally perform the jaw jerk on the patient by placing your left index finger on their chin and striking it with a tendon hammer.mouth should be little bit open ~ This should cause slight protrusion of the jaw.