WARM UP 4/29WARM UP 4/29

1.1. Write the 12 cranial nerves in orderWrite the 12 cranial nerves in order

2.2. What does each do?What does each do?

a. Medullaa. Medulla

b. Ponsb. Pons

c. Pituitaryc. Pituitary

d. Corpus collosumd. Corpus collosum

3. 4 ways to test the brain’s function.3. 4 ways to test the brain’s function.

NOTES Ch 11 4/29NOTES Ch 11 4/29

The eyeThe eye

EYE ANATOMYEYE ANATOMY

3 layers:3 layers:

1. Sclera 1. Sclera

* outer layer* outer layer

* white* white

* protects * protects and maintains and maintains shapeshape

2.2. CHLOROIDCHLOROID

* middle layer* middle layer

* many blood vessels* many blood vessels

3.3. RETINARETINA

* inner layer* inner layer

* where image is focused* where image is focused

CORNEA - Clear front of the eye CORNEA - Clear front of the eye

PUPIL – circular dark opening of the eyePUPIL – circular dark opening of the eye * close or bright light – constricts* close or bright light – constricts * far or dim light – dilates* far or dim light – dilates

IRIS - colored part of the eye (muscle)IRIS - colored part of the eye (muscle)- Due to the amount of melaninDue to the amount of melanin

- low melanin = blue- low melanin = blue

- high melanin = brown- high melanin = brown

- no melanin = pink (albinism) - no melanin = pink (albinism)

Muscles – sphincter and dilator papillaeMuscles – sphincter and dilator papillae

LENS LENS

* Behind iris and pupil* Behind iris and pupil

* elastic, disc-shaped, curved* elastic, disc-shaped, curved

* ciliary body – muscle that holds or * ciliary body – muscle that holds or

stretches lensstretches lens

* bends light rays so you can focus* bends light rays so you can focus

VITREOUS HUMORVITREOUS HUMOR

* clear jelly-like substance in the center * clear jelly-like substance in the center of the eyeof the eye

RETINARETINA

* Layer in the eye where image is focused * Layer in the eye where image is focused onon

Contains RODS and CONESContains RODS and CONES

RODS – sense black and whitesRODS – sense black and whites

CONES – sense colorsCONES – sense colors

After imageAfter image

BLIND SPOTBLIND SPOT

* Where the optic nerve meets the eye on * Where the optic nerve meets the eye on the retina there are no rods and cones so the retina there are no rods and cones so cannot see an image therecannot see an image there

BLIND SPOT TESTBLIND SPOT TEST

CONJUCTIVA – thin membrane that lines CONJUCTIVA – thin membrane that lines eyelids and eye; secrete mucous for eyelids and eye; secrete mucous for lubricationlubrication

LACRIMAL GLAND – secret LACRIMAL GLAND – secret tears and lubricating fluid tears and lubricating fluid into the eyeinto the eye

- located in the upper and - located in the upper and outer cornerouter corner

LACRIMAL DUCT – tube LACRIMAL DUCT – tube that tear drain into. Empties that tear drain into. Empties into the nasal cavity.into the nasal cavity.

                                                                                                                         

   

LABELING THE EYELABELING THE EYE

1.1. CorneaCornea

2.2. IrisIris

3.3. PupilPupil

4.4. LensLens

5.5. ConjunctivaConjunctiva

6.6. Ciliary bodyCiliary body

7.7. Vitreous humorVitreous humor

8.8. RetinaRetina

9.9. Blind spotBlind spot

10.10. Optic nerveOptic nerve

11.11. ChoriodChoriod

12.12. ScleraSclera

EYE PHYSIOLOGYEYE PHYSIOLOGY

Image Image Enters eye through pupil Enters eye through pupil cornea cornea lens lens RetinaRetinarods/ cones stimulatedrods/ cones stimulatedMessage through optic nerveMessage through optic nerveInterpreted at the occipital lobeInterpreted at the occipital lobe

The eye forms a reversed image on the retina. The eye forms a reversed image on the retina. Right at the beginning of your development as Right at the beginning of your development as a baby, your brain learned to turn the reversed a baby, your brain learned to turn the reversed image right-side up and to interpret it.image right-side up and to interpret it.

Your brain adds to, removes from, reorganizes, Your brain adds to, removes from, reorganizes, and interprets the sensory clues it receives. And and interprets the sensory clues it receives. And your senses can trick you. This is what we call your senses can trick you. This is what we call an optical illusion.an optical illusion.

                                      Look at the gray part. Which side (right or left) do you think is darker...?

Are the horizontal lines parallel, or do Are the horizontal lines parallel, or do they slope?they slope?

How many legs does this How many legs does this elephant have?elephant have?

Man playing a horn?Man playing a horn?Or woman's face?Or woman's face?

A rabbit, looking right?A rabbit, looking right?Or a duck, looking left?Or a duck, looking left?

A skull? A skull? Or a woman looking into a vanity Or a woman looking into a vanity

mirror?mirror?

A Native American profile? A Native American profile? Or an Eskimo entering a cave?Or an Eskimo entering a cave?

One face? One face? Or two profiles facing each other?Or two profiles facing each other?

Young woman or old woman?Young woman or old woman?

Which inner circle is bigger?Which inner circle is bigger?

Up or down?Up or down?

Which is your dominant eye?Which is your dominant eye?

Point your finger at an object in the room far Point your finger at an object in the room far away. Try to line your finger up with it.away. Try to line your finger up with it.

Now close your left eye, then open it and Now close your left eye, then open it and close your right eye. What eye has the close your right eye. What eye has the object lined up?object lined up?

That is your dominant eyeThat is your dominant eye

Test – Hole through your handTest – Hole through your hand

Roll a sheet of paper into a tube (longways)Roll a sheet of paper into a tube (longways)

Hold it up to your right eyeHold it up to your right eye

Hold your left hand in front of your left eye Hold your left hand in front of your left eye and move it out along the tubeand move it out along the tube

What happens?What happens?

Why 2 eyes?Why 2 eyes?

Each eye has a slightly different view, when Each eye has a slightly different view, when put together things looks 3D – DEPTH put together things looks 3D – DEPTH PERCEPTIONPERCEPTION

LABLAB

DEPTH PERCEPTION – ability to tell DEPTH PERCEPTION – ability to tell distances with the eyesdistances with the eyes