Cranial nerves introduction

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The 12 cranial nerves...

Listed from most anterior to most posterior

Olfactory nerve

Optic nerve

Oculomotor nerve

Trochlear nerve

Trigeminal nerve

Abducent nerve

Facial nerve

Vestibulocochlear nerve

Glossopharyngeal nerve

Vagus nerve

Accessory nerve

Hypoglossal nerve

Sensory or motor?

i) Sensory (afferent) modalities

General somatic sensory (GSS) - general sensation from skin

General visceral sensory (GVS) - general sensation from viscera

Special somatic sensory (SSS) - senses derived from ectoderm (sight, sound & balance)

Special visceral sensory (SVS)- senses derived from endoderm (taste)

ii) Motor (efferent) modalities

General somatic motor (GSM) - Skeletal muscles

General visceral motor (GVM) - Smooth muscles of gut & autonomic motor

Special visceral motor (SVM) - Muscles derived from pharyngeal arches

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Origin stories & exit points

i) Origins

Cerebrum = Olfactory & Optic nerves

Brainstem:

Midbrain = Trochlear nerve - posterior side

Midbrain - pontine junction = Oculomotor nerve

Pons = Trigeminal nerve

Pontine - medulla junction = Abducens, Facial & Vestibulocochlear nerves

Medulla Oblongata :

Glossopharyngeal, Vagus & Accessory nerves = Posterior to the olive

Hypoglossal = Anterior to the olive

ii) Exits

Listed anterior to posterior

Cribiform plate = Olfactory nerve

Optic canal = Optic nerve

Superior orbital fissure = Oculomotor, Trochlear, Opthalmic division of Trigeminal

Foramen rotundum = Maxillary division of Trigeminal

Foramen ovale = Mandibular division of Trigeminal

Internal acoustic meatus = Facial & Vestibulocochlear nerves

Jugular foramen = Glossopharyngeal, Vagus & Acessory nerves

Hypoglossal canal = Hypoglossal nerve

** Cranial nerves with the number 2 in them (Optic & Hypoglossal) exit through a canal of the same name + only cranial nerves that pass through canals! **

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Brainstem nuclei

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