cranial nerves - unit 3 - clinical anatomy lab

one

I

olfactory nerve

has only sensory fibers

starts in the nasal cavity

sense of smell

two

II

optic nerve

has only sensory fibers

starts at the retina of the eye

provides vision

three

III

oculomotor nerve

has only motor fibers

for voluntary eye movements

innervates 6 extrinsic muscles:

• Medial rectus

• superior rectus

• inferior rectus

• inferior oblique

• Levator palpebrae superioris

four

IV

trochlear nerve

has only motor fibers

for voluntary eye movements

Innervates the superior oblique

five

V

trigeminal nerve

A mix of sensory and motor fibers

• sensory: touch, pain, and temperature of the face & the anterior 2/3 of the tongue

• motor: controls the muscles for chewing

has three divisions

• ophthalmic: sensory only (V1)

• maxillary: sensory only (v2)

• mandibular: sensory and motor (v3)

six

VI

abducens nerve

has only motor fibers

Innervates the lateral rectus muscle of the eye

seven

VII

facial nerve

a mix of sensory and motor fibers

• sensory: taste for the anterior 2/3 of the tongue ( sweet, salty, sour, bitter, and umami)

• motor: innervates the muscles for facial expressions as well as regulates the lacrimal and salivary glands

eight

VIII

vestibulocochlear nerve

has only sensory fibers

has two branches:

• vestibular branch: for balance. detects or senses movements that are linear and angular/turning

• cochlear branch: for hearing. Responsible for hearing sounds

nine

IX

glossopharyngeal nerve

A mix of sensory and motor fibers

• Sensory: for taste in the posterior 1/3 of the tongue. Also has sensory neurons in the pharynx and eardrum

• motor: inervates the muscles for swallowing and the parotid salivary glands

ten

X

vagus nerves

A mix of sensory and motor fibers:

• sensory:

  • pharynx

  • external acoustic meatus

  • diaphragm

  • internal organs of the thoracic and abdominopelvic cavities

• motor:

  • palate

  • pharynx

  • autonomic motor fibers to internal organs

eleven

XI

Spinal accessory nerve

has only motor fibers

Innervates the trapezius and the sternocleidomastoid muscles in the neck

originates from the spinal cord

twelve

XII

hypoglossal nerve

has only motor fibers

innervates the muscles that move the tongue

Label the cranial nerves on the brain

1. olfactory

2. optic

3. ocuomotor

4. trochlear

5. trigeminal

6. abducens

7. facial

8. vestibulocochlear

9. glossopharyngeal

10. vagus

11. spinal accessory

12. hypoglossal