Sensory input from the upper respiratory tract reaches the central nervous system through which cranial nerve?

Sensory input from the upper respiratory tract reaches the central nervous system through which cranial nerve?

• A. Trigeminal nerve (CN V)
• B. Glossopharyngeal nerve (CN IX)
• C. Vagus nerve (CN X)
• D. Facial nerve (CN VII)

Answer: (A)

General sensation from the mucosa of the upper airway is carried to the brain by the trigeminal nerve. The nasal cavity and paranasal sinuses are supplied by branches of CN V (the ophthalmic and maxillary divisions), which convey touch, pain, and temperature as general somatic afferent information. This information travels from the nasal mucosa to the trigeminal ganglion and then to the brainstem nuclei. Sensation from smell, a separate type of input, travels via the olfactory nerve (CN I), not CN V. Sensory fibers from the pharynx and larynx are carried mainly by the glossopharyngeal and vagus nerves, not by the trigeminal, which is why the trigeminal nerve is the best answer for sensory input from the upper respiratory tract.

General sensation from the mucosa of the upper airway is carried to the brain by the trigeminal nerve. The nasal cavity and paranasal sinuses are supplied by branches of CN V (the ophthalmic and maxillary divisions), which convey touch, pain, and temperature as general somatic afferent information. This information travels from the nasal mucosa to the trigeminal ganglion and then to the brainstem nuclei. Sensation from smell, a separate type of input, travels via the olfactory nerve (CN I), not CN V. Sensory fibers from the pharynx and larynx are carried mainly by the glossopharyngeal and vagus nerves, not by the trigeminal, which is why the trigeminal nerve is the best answer for sensory input from the upper respiratory tract.