Bell's Palsy

What is the reflex arc for Bells phenomenon?

[Dr Sharma]

Hi there. Bell’s phenomenon is a normal defense reflex present on three quarters of the population resulting in the elevation of globes when blinking or when there approached threateningly like by touching the cornea with finger. It is noticeable when orbicularis oculi muscle becomes weak as in bilateral facial palsy associated with gullian barre syndrome. it is usually present behind forcibly closed lids in most of the healthy people and should not be treated as a pathognomic sign. The afferent is nasociliary brach of the ophthalmic division V1 of the fifth cranial nerve or the trigeminal nerve. Efferent is obviously the seventh or the facial nerve possibly mediated by a medullary centre. Hope this helps. Take care.