MRCP UK EXAMINATIONS

NEUROLOGY

PERIPHERAL NEUROPATHY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
gag reflex
A
glossopharyngeal
B
vagus
C
trigeminal
D
optic
Explanation: 

Detailed explanation-1: -Glossopharyngeal nerve lesions produce difficulty swallowing; impairment of taste over the posterior one-third of the tongue and palate; impaired sensation over the posterior one-third of the tongue, palate, and pharynx; an absent gag reflex; and dysfunction of the parotid gland.

Detailed explanation-2: -The afferent limb of the reflex is supplied by the glossopharyngeal nerve (cranial nerve IX), which inputs to the nucleus solitarius and the spinal trigeminal nucleus. The efferent limb is supplied by the vagus nerve (cranial nerve X) from the nucleus ambiguus.

Detailed explanation-3: -CN 9 is mainly sensory supplying the mucous membranes of the soft palate and pharynx; it serves as the afferent limb of the gag reflex. In addition to supplying thoracic and abdominal viscera the CN 10 innervates the muscles of the pharynx, palate and vocal cords and so controls phonation and swallowing.

Detailed explanation-4: -The glossopharyngeal nerve is the ninth set of 12 cranial nerves (CN IX). It provides motor, parasympathetic and sensory information to your mouth and throat. Among its many functions, the nerve helps raise part of your throat, enabling swallowing.

There is 1 question to complete.