Cranial Nerves

• Inferior surface of the brain as it appears on gross dissection.

Nerves in nasal cavity synapse within olfactory bulbs.

The Olfactory nerve (I) – for sense of smell.

The Optic nerve (II) - carries visual information.

The Oculomotor nerve (III) - Controls 4 of

the 6 extrinsic muscles of the eye.

The Trochlear nerve (IV)– Innervates superior oblique eye muscle.

Largest of all the

cranial nerves

1) Ophthalmic branch

skin, lacrimal gland

• The Trigeminal nerve (V)

2) Maxillary branchlower eyelid, upper jaw

3) Mandibular branch

tongue, lower teeth

Has 3 Branches

The Facial nerve (VII)Controls muscles of scalp and facial

expression.Muscles of mastication and speech.

The Abducens nerve (VI)Innervates lateral rectus muscle of eye (abduction!)

Pressure sensations from face.Taste sensations from anterior 2/3 of tongue.

The Facial nerve (VII)

The Vestibulocochlear nerve (VIII)– Monitors sense of balance, position and

movement and also monitors hearing.

The Glossopharyngeal nerve (IX)

Controls swallowing

Taste sensation from posterior 1/3 tongue.

Detects O2 and CO2 content of bloodin carotid artery.

Vital to autonomic control of visceral function

The Vagus nerve (X)

The Accessory nerve (XI)– Internal branch

Innervates swallowing muscles. – External branch

Controls sternocleidomastoid and trapezius.

The Hypoglossal nerve (XII)Voluntary food mixing, swallowing and speech.

Control of tongue movements.

• The Accessory nerve (XI) and Hypoglossal nerve (XII)

Olfactory Nerve (II)

Fig

18.6

FYI

Optic Nerve (II)

Oculomotor Nerve (III)

Trochlear Nerve (IV)

Abducens Nerve (VI)

Trigeminal Nerve (V)

Facial Nerve (VII)

Vestibulocochlear Nerve (VIII)

Glossopharyngeal Nerve (IX)

Vagus Nerve (X)

Accessory Nerve (XI)

Hypoglossal Nerve (XII)

Fig

18.17

FYI