Afferent component of corneal reflex is mediated by

AIPG 2006 Anatomy and Genetics

001. Afferent component of corneal reflex is mediated by:

1. Vagus nerve.

2. Facial nerve.

3. Trigeminal nerve.

4. Glossopharyngeal nerve.

Answer

2. Trigeminal Nerve

Reference

Golwalia Physical Diagnosis 8^th Edition Page 533

Quality

Spotter

Status

Repeat

QTDF

All Books

Discussion

When a wisp of cotton wool twisted to a point is used for touching the cornea (the eye being approached from the side to avoid a winking reflex), with the patient’s lower lid held down and he be asked to look up to the side, the normal response consists of an instantaneous closure of the eyes

Explanation

Ä The afferent component is mediated through the fifth nerve – Trigeminal Nerve

Ä The efferent component is mediated through the seventh cranial nerve – Facial nerve

Comments

Corneal Reflex is absent in

1. Trigeminal nerve lesion
2. Cerebellopontine angle tumour
3. Aged persons after Cataract Surgery
4. Loss of corneal reflex in the absence of drug overdose is a poor prognostic indicator

Tips

Corneomandibular reflex : consists of movement of the jaw to the opposite side along with eyelid closure after stimulation of one cornea. It appears contralaterally after a hemispheric lesion and bilaterally in coma.