Nerve Responsible for Sneezing | Crack AIPGDEE 2016

Tickling sensation felt in nose by or sneezing is carried in which nerve

a) Facial nerve

b) Glossopharyngeal nerve

c) Nasopalatine nerve

d) Nasociliary nerve

Ans(d) 

Sneezing reflex is triggered by a variety of stimuli, the most common of which is Stimulation of nasal mucosa (trigcminul nerve endings) by mechanical or chemical stimuli. 

Sneezing reflex has 2 phases

a) Nasal 

•The afferent limb of the nasal phase consists of the ethmoidal and olfactory (cranial

nerve T) which projects to sneezing centre in medulla oblongata.

•So from above reference it is clear that tactile sensation before sneezing is due to ethmoidal nerve. which is  the branch of nasociliary nerve.

•So answer is nasociliary nerve i.c, option d.

•The efferent limb of nasal phase consists of preganglionic fibres of greater petrosal nerve (cranial nerve VlI ) and

the sphenopalatine ganglia (cranial nerve VII) which innervates glands and blood vessels in the nose.

b) Respiratory

•Respiratory phase of the sneezing reflex commences when a critical number of inspiratory and expiratory neurons

arc recruited by sneezing centre.

Another reference - sternutogenesis

A sneeze involves dozens of muscles in the face, chest and abdomen, all operuuug in a correct sequence that has been hard wired in the brain and spinal cord. The sequence is mediated by trigerninal nerve particularly the anterior ethmoidal, posterior nasal and infraorbital brunches.