File:A treatise on physiology and hygiene for educational institutions and general readers (1884) (14590335769).jpg The cranial nerves are twelve pairs of nerves that emerge directly from the brain , including the brainstem , in contrast to the spinal nerves which emerge from segments of the spinal cord . Each cranial nerve has a specific function and is numbered based on its location from the front of the brain to the back. The following table provides an overview of the cranial nerves, their primary functions, and their anatomical pathways.
Number
Name
Function
Pathway
I
Olfactory nerve
Sense of smell
From the olfactory epithelium to the olfactory bulb
II
Optic nerve
Vision
From the retina to the optic chiasm and then to the lateral geniculate nucleus
III
Oculomotor nerve
Eye movement , pupil constriction
From the midbrain to the extraocular muscles and ciliary ganglion
IV
Trochlear nerve
Eye movement (superior oblique muscle)
From the midbrain to the superior oblique muscle
V
Trigeminal nerve
Facial sensation , mastication
From the pons to the face , with three branches: ophthalmic , maxillary , and mandibular
VI
Abducens nerve
Eye movement (lateral rectus muscle)
From the pons to the lateral rectus muscle
VII
Facial nerve
Facial expression , taste (anterior 2/3 of the tongue), salivation , tear production
From the pons to the facial muscles , submandibular gland , sublingual gland , and lacrimal gland
VIII
Vestibulocochlear nerve
Hearing , balance
From the inner ear to the pons
IX
Glossopharyngeal nerve
Taste (posterior 1/3 of the tongue), salivation , swallowing
From the medulla oblongata to the pharynx , parotid gland , and posterior tongue
X
Vagus nerve
Parasympathetic control of the heart, lungs, and digestive tract, taste , swallowing
From the medulla oblongata to the thoracic and abdominal organs
XI
Accessory nerve
Shoulder and neck movement
From the medulla oblongata and spinal cord to the sternocleidomastoid and trapezius muscles
XII
Hypoglossal nerve
Tongue movement
From the medulla oblongata to the muscles of the tongue
See Also [ edit ]
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