Olfactory Optic Oculomotor Trochlear Trigeminal (3 divisions…) Abducens Facial Vestibulocochlear (2 divisions) Glossopharyngeal

Olfactory Nerves Eric Johnson

• Sensory Nerves associated with sense of smell

• Contains only axons of sensory, bipolar neurons.

• Located in upper nasal cavity• Olfactory receptor cells carry • impulses to neurons in olfactory • bulbs• Sensory impulses travel from • bulbs along olfactory tracts to the• cerebral centers where they are• interpreted into the sensation of • smell.

Optic Nerves – Jack Baesman• A pair of nerves that leads from the eyes to the brain• Enable sight• Sensory nerves• The cell bodies form ganglion in the eyes, and the axons

pass through the optic foramina• The impulses are interpreted in the visual cortices of

the occipital lobes• Bipolar

Oculomotor Nerves Primarily Motor Arise from the midbrain Pass into the orbits of the eyes The motor fibers transmit

impulses to the muscles to:

Raise eyelids Move eyes Adjust the amount of light

entering the eyes Focus lenses

Primarily Motor The motor fibers

transmit impulses to move the eyes.

Some sensory fibers transmit impulses associated with the condition of the muscles.

Smallest cranial nerves

Arise from the midbrain

Trochlear Nerve

Trigeminal Nerves Largest cranial nerves Arise from pons Mixed nerves Sensory portions more

extensive than motor portions 3 large branches

Ophthalmic Maxillary Mandibular

Abducens

• 6th cranial nerve• Small nerves that

originate from the pons near the medulla oblongata

• Are primarily motor• Enter the orbit of the eye

and control motor impulses in the muscles that move the eye

#7: Facial NerveBy Lauren Sayers

• Location: Arises from the lower part of the pons + emerges on the sides of the face.

• Function: Sensory fibers transmit impulses associated with taste receptors of the anterior tongue.Motor fibers transmit impulses to muscles of facial expression/tear/salivary glands.

Vestibulocochlear nerves (VIII)• Sensory nerves from medulla

oblongata

• Two parts- vestibular branch and cochlear branch

• Vestibular Branch- cell body associated with inner ear and reflexes that help maintain equilibrium.

• Cochlear Branch- Cell body houses hearing receptors, these signals pass through medulla oblongata and pons to be sent to the temporal lobe, where they are interpreted and sent back out.

Glossopharyngeal nerves 9th pair Arise from medulla

oblongata

Predominately sensory fibers, carry impulses to linings of pharynx, tonsils, back of tongue

Innervate muscles of the pharynx that function in swallowing

Vagus Nerves 10th pair Originate in the medulla

oblongata , extend down the neck into chest abdomen

Somatic and autonomic branches

Somatic fibers carry impulses to larynx, help with speech and swallowing

Autonomic fibers supply heart and smooth muscles and glands in thorax and abdomen

Accessory Nerves 11th pair Originate in medulla

oblongata and spinal cord (have cranial and spinal branches)

Cranial branch- joins vagus nerve, innervates muscles of soft palate, pharynx, and larynx

Spinal branch- drops into neck, innervaes trapezius and sternocleidomastoid muscles

Hypoglossal nerve

12th pair Arise from medulla oblongata, into

tongue Motor fibers innervate muscles that

move the tongue for speaking, chewing, and swallowing.