Anatomy and Physiology Lab 11: Cranial Nerves, Eye, and Ear

CN I

Olfactory nerve

• SENSORY

• olfactory bulb on the end

• sits on cribiform plate

• When we are sick, CN I can become compressed which is why we can loose our sense of smell

CN II

Optic nerve

• SENSORY

• passes through optic canal

• connects to eye

• one optic nerve per eye

• the two optic nerves are connected by the optic chiasm

CN III

Oculomotor

• MOVEMENT

• passes through superior orbital fissure

• eye movement

• constrict pupil (parasympathetic)

CN IV

Trochlear

• MOTOR

• passes through superior orbital fissure

• 1 specific eye muscle

• can cause double vision or eye misalignment if damaged

CN V

Trigeminal

• 3 branches

  • Ophthalmic: SENSORY to superior face; passes thru superior orbital fissure

  • Maxillary: SENSORY to middle face; passes through foramen rotundum

  • Mandibular: MOTOR and SENSORY to inferior face/jawline (opens and closes jaw); passes through foramen ovale

CN VI

Abducens

• MOTOR

• passes through Superior orbital fissure

• abducts eye (move one specific eye muscle)

CN VII

Facial

• MOTOR and SENSORY

• passes through internal acuoustic meatus

• facial expressions and blinking

• salivation

• taste to front 2/3 of tongue

• sensory to ear

CN VIII

Vestibulocochlear

• SENSORY (Balance and Hearing)

• passes through internal acoustic meatus

• stays in inner ear

• 1 branch attaches to cochlea

• 1 branch attaches to semicircular canals

CN IX

Glossopharyngeal

• MOTOR and SENSORY

• passes through jugular foramen

• swallowing, salivation

• taste of back 1/3 of tongue

• sensory to middle ear, auditory tube, oralpharynx

CN X

Vagus

• MOTOR and SENSORY

• passes through jugular foramen

• Motor: swallowing, decrease heart rate and respiration

• General sensory: ear, thoracic, and abdominal organs

• Special sensory: taste of epiglottis (back of throat)

CN XI

Accessory

• MOTOR

• passes through jugular foramen

• neck and shoulder movement

CN XII

Hypoglossal

• MOTOR

• passes through hypoglossal canal

• tongue movement

O.O.O.T.T.A.F.V.G.V.A.H

Some say marry money, but my brother says big brain matter more.

***figure out a way to remember order of cranial nerves

What are these?

orbits/ eye sockets

What are these?

extraocular muscles

What layer of the eye is this?

Cornea

Where is the aqueous humor?

Right under the cornea and on top of the iris (?). It helps keep the shape of the cornea.

What layer of the eye is this?

Sclera (whites of the eye)

What layer of the eyes is this?

Choroid

What layer of the eye is this?

Ciliary body (sits on top of the iris)

What is this?

Lens

What layer of the eye is this?

Iris

what part of the eye is this?

pupil

What layer of the eye is this?

Retina

Where is the optic disk?

In the back of the eye, on the inside. It is where the optic nerve connects to the eye. There is a blind spot in that location because the optic disk has no rods or cones to detect light.

What is the order of the layers of the eye from superficial to deep?

1.) cornea

2.) aqueous humor

3.) sclera

4.) iris/ciliary body (surrounds iris)

5.) choroid

6.) retina

7.) lens

8.) vitreous humor

Anterior segment

Posterior segment

Middle ear

Inner ear

Auricle

External auditory canal

Tympanic membrane

aka ear drum

Malleolus

Incus

Stapes

Auditory tube

Vestibule

Cochlea

Semicircular canal