Chapter 14 - Section 14.6 - Study Guide - Assess Your Learning Outcomes - Page 555: 1

The brain communicates with the rest of the body by the spinal cord, but also through twelve pairs of nerves, the cranial nerves CNs: This group includes the following:' CN I : Cranial nerve #1 is the olfactory nerve. It originates in the olfactory and nasal mucosa and exits the skull through the cribriform foramina of the ethmoid bone. CN II: This is the optic nerve. It originates in the retina and exits the skull through the optic foramen CN III, the oculomotor is predominantly motor. It originates in the midbrain of the brain stem BS) and leaves the skull through the superior orbital foramen. CN IV is the trochlear nerve. This, too, is predominantly motor. It originates in the midbrain (BS) and leaves the skull through the superior orbital fissure CN V is the trigeminal nerve. As the name implies this nerve has three parts (roots): these are the ophthalmic (V1) the the maxillary ( V2) and the mandibular (V3) V1 leaves the skull through the superior orbital fissure; V2 exits by way of the foramen rotundum, and the infraorbital foramen; V3 is a mixed nerve; its motor fibers derive from the midbrain. It leaves the skull through the foramen ovale CN VI This is the abducens nerve. It originates in the inferior pons (BS) and exits the skull through the superior orbital fissure.

CN VII: The facial nerve, is associated with the pons (BS), and leaves the brain by way of the internal acoustic meatus and the stylomastoid foramen. CN VIII. This is the vestibulocochlear. It is also associated with the pons (BS). Its route of exit is the internal acoustic meatus. C IX. The glossopharyngeal is a mixed nerve. Its motor fibers originate in the medulla oblongata. It l leaves the brain through jugular foramen CN X. This is the vagus. Like the glossopharyngeal its associated with the medulla and exits the skull through the jugular foramen. CN XI. The spinal accessory originates in the spinal cord and connects with the brain through the jugular foramen. CN XII . Number 12, has its own exit canal , the the hypoglossal canal. It is a complex nerve which originates in the medulla and functions in tongue movements related to food manipulation, swallowing, and speech.