Cranial Nerves

Cranial Nerves

The 12 pairs of nerves that bring information to the brain, primarily innervating the head and neck.

Olfactory Nerve

CN I; a purely sensory nerve responsible for the sense of smell.

Optic Nerve

CN II; a purely sensory nerve responsible for the sense of vision.

Oculomotor Nerve

CN III; a motor nerve innervating muscles that move the eyeball.

Trochlear Nerve

CN IV; a motor nerve innervating the superior oblique muscle of the eye.

Trigeminal Nerve

CN V; a mixed nerve providing sensory information from the face and motor innervation to muscles of mastication.

Abducens Nerve

CN VI; a motor nerve that innervates the lateral rectus muscle, responsible for eye abduction.

Facial Nerve

CN VII; a mixed nerve responsible for facial expressions, taste, and innervating glands.

Vestibulocochlear Nerve

CN VIII; a sensory nerve responsible for hearing and equilibrium.

Glossopharyngeal Nerve

CN IX; a mixed nerve involved in taste and motor functions in the pharynx.

Vagus Nerve

CN X; a mixed nerve that wanders beyond the head and neck affecting thoracic and abdominal organs.

Accessory Nerve

CN XI; a motor nerve that innervates muscles moving the head and neck.

Hypoglossal Nerve

CN XII; a motor nerve that controls tongue movements.

Cerebrum

The part of the brain where CN I (Olfactory) and CN II (Optic) originate.

Brainstem

The part of the brain where most of the cranial nerves (CN III - CN XII) originate.

Sensory Nerves

Cranial nerves I, II, and VIII; responsible solely for sensory functions.

Mixed Nerves

Cranial nerves V, VII, IX, and X; containing both sensory and motor axons.

Motor Nerves

Cranial nerves III, IV, VI, XI, and XII; primarily containing motor axons.

Cranial Nerve Naming

Each cranial nerve is designated by 'CN', its Roman numeral, its name, and the term 'nerve'.

Oculomotor Functions

Controls eye movements, eyelid elevation, constriction of the pupil, and lens shape adjustment.

The facial nerve has five branches: temporal, zygomatic, buccal, mandibular, and cervical

What are the five facial nerve branches?

Cranial Nerve Passageways

Cranial nerves enter/exit the skull through specific foramina and canals.

Vagus Nerve Unique Feature

The only cranial nerve that extends beyond the head and neck, impacting the thoracic and abdominal cavities.

Trochlea

A fibrous loop that holds the superior oblique muscle, innervated by CN IV.

Jugular Foramen

The passage for cranial nerves IX, X, and XI.

Hypoglossal Canal

The passage through which the hypoglossal nerve (CN XII) enters.

Olfactory Bulb

The structure where the olfactory nerve synapses before sending impulses to the olfactory cortex.