pinna or auricle

(earlobe)

"oldsightedness"

farsightedness of old age

• Connects the middle ear cavity with the throat (pharynx)
• Allows pressure to equalize on the 2 sides of the TM (tympanic membrane)

Keratitis

Inflammation of the cornea

Where is the Malleus located?

Describe the Malleus.

Middle ear

shaped like a hammer and attached

to the tympanic membrane

Parts of the middle ear

-Malleus

-Incus

-Stapes

Where is incus located

and describe it

Middle ear

shaped like an anvil and attached to the malleus

Where is stapes located

and describe it

Middle ear

Shaped like a saddle and attached to the oval window

Which fluids are important to the sensory functions of the inner ear?

Endolymph

Which cranial nerve is associated with hearing?

CN VIII

What part of the ear holds the receptors related to equilibrium?

The inner ear

Otitis media

Inflammation or infection of the middle ear

Myringotomy

Incision in eardrum to release fluid trapped inside

   1 – skull                             7 - incus  
   2 – ear canal                       8 - stapes   
   3 – pinna (auricle)               9 - labyrinth (semicircular canals)    
   4 – tympanum                   10 - cochlea   
   5 – fenestra ovalis             11 - auditory nerve/tube      
   6 – malleus                       12 - eustachian tube       

Sclera

whites of the eye

outer layer of eye

has white thick connective tissue

has transparent center (cornea) allows light into eye

Iris

"Colored" part of the eye

Ring of colored muscle that adjusts opening of pupil

The mucous membrane that covers

the front of the eye is?

Conjunctiva

What relaxes to flatten lense

for distance objects

and

contracts causing lense to bulge becoming convex &

stronger power for closer objects?

What does it produce?

Ciliary muscles

Produces aqueous humor for anterior chamber

Pupillary muscles

1.  Constrictor (circular)- encircles pupil

-narrows pupil to let in LESS light

2.  Dilator (radial)- like spokes of a wheel

-contrast to let in MORE light

What are the 3 layers

of the eye?

1.  Sclera

 2. Choroid

3.  Retina

In which area contains the greatest concentration

of cones on the retina?

Fovea centralis

Middle layer

Nourishing layer

Has rich blood supply

Has brown pigment that keeps light from scattering

Lens & iris are part of this layer

Choroid layer

Retina

- Inner layer

- Very delicate

- Layers of sensory neurons called rods & cones

- Responsible for black & white vision

- More dense on sides of retina

- Better for night vision

Rods

- Responsible for colored vision

- More dense in center of retina

- Better for day vision

Cones

Fovea Centralis

- Contains only cones

- Area of sharpest vision

Has 0 rods or cones

Blind spot

Where optic nerve attaches to eye

Optic disc

Anterior Chamber

- In front of lens

- Contains aqueous humor

Posterior Chamber

- Behind lens

- Contains vitreous humor (jellylike)

What are the 4 refractive structures of the eye?

                             1. Cornea

2. Aqueous humor

                     3. Lens (only 1 to change shape)

4. Vitreous humor

What are the 5 nerves that affect the eye and what are their actions?

                             1. Optic: sn

   2. Oculomotor: mn

                             3. Trochlear: mn

4. Abducens: mn

                 5. Opthalmic: (branch of trigeminal nerve)

                      -sensory nerve for pain, touch,

                                         pressure, &temp)

The pathway of light for vision

(9)

1. Conjunctiva                           6. Vitreous humor *

2. Cornea *                               7. Retina

3. Aqueous humor *                   8. Optic nerve

4. Pupil                                     9. Brain in occipital lobe

5. Lens

* Doesn't change shape-bends/refracts light

What are the 2 functions of the ear?

1. Hearing

                     2. Balance  (Equilibrium)

What are the 3 areas of the ear?

List the structural parts of each area

1. Outer                                         3. Inner

    -auricle (pinna)                                           -vestibule

    -External auditory canal                               -semicircular canals

    -Ceruminous glands                                     -cochlea

2.Middle

   -TM

   -ossicles

   -oval window

   -eustachian tube

What does the pinna do?

Directs sound into ear

The part of the ear that moistens & lubricates is?

Ceruminous glands

What parts of the ear vibrates?

1. TM

       2. Ossicles

             3. Oval window

What 2 parts of the ear are responsible for

balance?

1. Vestibule

2. Semicircular canals

Eustachian tube is responsible for?

Equalizing air pressure in middle ear

so TM will vibrate properly

Watery fluid found in labyrinth

Perilymph

Labyrinth contains what 3?

1. Cochlea

2. Vestibule

3. Semicircular canals

Organ of Corti

Sensory neurons in cochlea that's

stimulated by vibrations

-What has 3 in each ear at an angle to each other

-part of cochlea

-has sensory receptors that are sensitive to movement

-impulses are carried by acoustic nerve to brain

Semicircular Canals

area b/w cochlea & semicircular canals

-gelatinous substand w/ calcium stones embedded

-stones shift w/ positioning d/t gravity

-sensory receptors are stimulated & impulse carried by

acoustic nerve to brain

Vestibule

Pathway of sound for hearing

(13)

1. Pinna                                           10. Endolymph

2.Ext. aud.canal                                11.Organ of Corti

3.TM                                                12.Acoustic nerve

4.Malleus                                          13.Brain (Temporal)

5.Incus

6.Stapes

7.Oval window

8.Perilymph

9.Membraneous labyrinth