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External Anatomy of the Eye

Eyelids: Protection, Lubrication

Eyelashes: Protection

Glands: Meibomian and CiliaryMeibomian: Oil glands, modified

sebaceous glands on eyelids

Ciliary: Modified sweat glands.

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Third eye-lid

Gathers dust

and produces

eye crispies.

In other animals

It can cover theEye.

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What is the Lacrimal apparatus and

what does it do?

Lacrimal apparatus. Fig 12.5

Lacrimal glands: release tears

Lacrimal ducts (eyelid) and canals (nose) Nasolacrimal ducts: empties into the nose

Lacrimal Secretion: Tears have

antibodies and lysozyme. Cleans,moistens.

Why is it called a healthy cry?

Lysozyme

http://www.npr.org/blogs/health/2012/01/19/145466010/how-tears-go-pac-man-to-beat-bacteria?ps=sh_stcatimghttp://cim.ucdavis.edu/EyeRelease/Interface/TopFrame.htmhttp://www.npr.org/blogs/health/2012/01/19/145466010/how-tears-go-pac-man-to-beat-bacteria?ps=sh_stcatimghttp://cim.ucdavis.edu/EyeRelease/Interface/TopFrame.htm

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What are the Muscles of the eye

and how do they move it?

Lateral rectus: Moves eye laterally

Medial rectus: Moves eye medially

Superior rectus: Moves eye up Inferior rectus: Moves eye down

S & I Obliques

Fig 8.15, 197 Fig 12.7, pg 296

Practice using

The Eye Muscles

http://cim.ucdavis.edu/EyeRelease/Interface/TopFrame.htmhttp://cim.ucdavis.edu/EyeRelease/Interface/TopFrame.htmhttp://cim.ucdavis.edu/EyeRelease/Interface/TopFrame.htm

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What are the internal structures

of the eye? Pg. 295, Fig 12.6

Sclera: white of the eye

Cornea: Clear

Iris: colorful part of the eye

Pupil: Opening of the Iris

Lens and ciliary body: Ciliary body holds

the lens in place. The lens focuses light on

the back of the eye.

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What fills the inner eye? Pg 298

Aqueous Humor: Circulates from the

cornea to the Lens through the canal of

Schlemm.

Vitreous Humor: In the space behind the

lens. Keeps the eyes shape, and keeps

intraocular pressure stable.

Floaters?

Glaucomma?

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What lines the back of the eye?

Retina: photoreceptor layer

Rods: Black and white

Cones: Color

Choroid coat: Dark, vascularized layer.

Absorbs light. *Non-humans are different

Sclera: Thick, white covering

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How do you see? Pg. 299

.

Fields of Vision

http://www.innerbody.com/anim/vision.htmlhttp://www.innerbody.com/anim/vision.html

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Light travels through the

Cornea to the Aqueous humor to the Pupil tothe lens.

In the Lens light is bent so that it will hit the

Retina of the eye.To get to the Fovea Centrals light must

continue to pass through Vitreous humor.

Light then hits the Retina where Rods andCones interpret the image and sends it tothe Optic nerve to the brain.

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Where is your vision the best and

the worst?

Worst vision: The blind spot. To find

your blind spot go to pg 297 in the book.

Blind spot is where the optic nerve takes theimage to your brain. There are no rods or

cones here. Your brain just fills in the gaps.

Best vision: Fovea Centralis. Lateral tothe blind spot, only contains cones. This

is the spot of greatest visual acuity.

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Focal

plane

Light

Lens

Emmetropia

(normal)

Myopia

(nearsightedness)

Hyperopia

(farsightedness)

Presbyopia

(aged)

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Why do cones see better than

rods?

See Fig 12.8

Many Rods, one nerve = blurred edges.

One Cone, one nerve = crisp lines. Which do you think causes Night Blindness?

What type of cones do you have:

Blue cones: see blue light Green cones: see green light

Red cones: see red and green light.

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Component colors are detected by cone cells in theretina.All colors in the visible spectrum can be represented as a

combination of red, green, and blue. In the retina, a full-color image is broken up into component colors by conecells specialized to detect red light (long wavelength),green light (med. wavelength), blue light (shortwavelength).

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What is colorblindness?

The lack of a type of cone, or all cones.

Sex-linked gene.

Men suffer from color blindness moreoften than females.

Vision of theColorblind

http://www.webexhibits.org/causesofcolor/2.htmlhttp://www.webexhibits.org/causesofcolor/2.htmlhttp://www.michaelbach.de/ot/http://www.webexhibits.org/causesofcolor/2.htmlhttp://www.webexhibits.org/causesofcolor/2.htmlhttp://www.webexhibits.org/causesofcolor/2.htmlhttp://www.michaelbach.de/ot/

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Steps

to

LASIK

Surgery

How is Lasiks

performed?

http://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.medeyelasik.com/http://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=GaoA4PLb7hchttp://www.medeyelasik.com/

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Optic nerve

Optic tract

Lateral geniculate nucleus

Optic radiation

Optic chiasm

Primary visual cortex

Illusions

More Illusions

http://www.michaelbach.de/ot/http://www.npr.org/templates/story/story.php?storyId=1902700http://www.michaelbach.de/ot/http://www.michaelbach.de/ot/http://www.npr.org/templates/story/story.php?storyId=1902700

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The Ear

Pg. 302& 303

Functions: Hearing and

Equilibrium.

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External Ear

Auricle

External Auditory Meatus-2.5 cm long

leads to Middle ear

How the

Ear hears.

http://www.medindia.net/animation/ear_anatomy.asphttp://www.medindia.net/animation/ear_anatomy.asphttp://www.medindia.net/animation/ear_anatomy.asp

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The Middle Ear

Tympanic Cavity: air-filled space

Tympanic Membrane- ear drum

Pressure changes cause it to vibrate, enhances

the sound wave Auditory Ossicles: smallest bones in the

body. Malleus, incus, and stapes.

The Stapes vibrate at the oval windowcausing fluid in the inner ear to move,stimulating hearing receptors.

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STAPES

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INCUS

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MALLEUS

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Auditory tube mucous membranes

connect directly with the middle ear linings.

Thus, mucous membrane infections of thethroat may spread through these tubes and

cause a middle ear infection.

Question: Why is it important to keep a

babies head up when bottle feeding?

How the

Tubes work

Xylitol gum and chewing it

could help prevent ear

infections.

http://www.cleanvideosearch.com/media/action/yt/watch?videoId=dCCh5mI3f8Qhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=dCCh5mI3f8Qhttp://www.medindia.net/animation/ear_anatomy.asphttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=dCCh5mI3f8Qhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=dCCh5mI3f8Qhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=dCCh5mI3f8Qhttp://www.medindia.net/animation/ear_anatomy.asp

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Inner Ear. Pg. 304

Cochlea: hearing Oval Window: the stapes vibrates this in

order for your nerves to fire and for you to

hear sound.

Review of the Ear:In depth on Cochlea

And Hearing

Sound on Cochlea

http://www.sumanasinc.com/webcontent/animations/content/soundtransduction.htmlhttp://www.sumanasinc.com/webcontent/animations/content/soundtransduction.htmlhttp://www.sumanasinc.com/webcontent/animations/content/soundtransduction.htmlhttp://www.hhmi.org/biointeractive/media/cochlea-lg.movhttp://www.hhmi.org/biointeractive/media/cochlea-lg.movhttp://www.sumanasinc.com/webcontent/animations/content/soundtransduction.htmlhttp://www.neurophys.wisc.edu/animations/corti155.mov

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Inner Ear: pg. 306 - 307

Semicircular Canals: maintain equilibrium

The vestibular system

http://www.sumanasinc.com/webcontent/animations/content/vestibular.htmlhttp://www.neurophys.wisc.edu/animations/cochlmtn.movhttp://www.sumanasinc.com/webcontent/animations/content/vestibular.htmlhttp://www.neurophys.wisc.edu/animations/cochlmtn.movhttp://oldsite.vislab.usyd.edu.au/projects/balance/balance.mpg

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Hearing Illusions

http://listverse.com/2008/02/29/top-10-incredible-sound-illusions/http://www.medindia.net/animation/ear_anatomy.asphttp://listverse.com/2008/02/29/top-10-incredible-sound-illusions/http://www.medindia.net/animation/ear_anatomy.asp

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The Nose. Fig 12.3

Smells using Olfactory Receptors

Yellow-brown mass located at the top of each

nasal cavity

Size of a postage stamp.

Sex and

Smell

Factoid:These swirl the

Air so that

Dust and germs

Stick to the

Mucus.

How we smell

http://www.pbs.org/wgbh/evolution/library/01/6/l_016_08.htmlhttp://www.pbs.org/wgbh/evolution/library/01/6/l_016_08.htmlhttp://www.bbc.co.uk/science/humanbody/body/factfiles/smell/smell_ani_f5.swfhttp://oldsite.vislab.usyd.edu.au/projects/balance/balance.mpghttp://www.bbc.co.uk/science/humanbody/body/factfiles/smell/smell_ani_f5.swfhttp://oldsite.vislab.usyd.edu.au/projects/balance/balance.mpghttp://www.pbs.org/wgbh/evolution/library/01/6/l_016_08.htmlhttp://www.pbs.org/wgbh/evolution/library/01/6/l_016_08.htmlhttp://www.pbs.org/wgbh/evolution/library/01/6/l_016_08.html

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How do olfactory receptor cells

smell?

Use Olfactory Hairs

Must be covered in mucus

Chemicals dissolve in mucus

Trigger nerve Olfactory Nerve

Connects to the Olfactory Bulb in Brain.Travels to temporal lobe for interpretation.

Tied to the limbic system (emotional system)of the brain. Smells stimulate memories.

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Interesting Nose facts

Olfactory neurons that are over stimulated shutoff. (Cant smell X after a while.)

Anosmias: loss of smell due to head injuries,nasal cavity inflammation (cold, allergy,smoking) or age. Often caused by a zinc deficiency

Olfactory auras: epileptics may have smell

hallucinations before a seizure. Because dust in space does not settleAustronoauts sneeze about 100 times a day!

h

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The Tongue.

Fig. 12.4

.

Factoid:You can detect

and distinguish

between 10,000

odors, but

only 5 tastes.

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How Do You Taste? Gustatory cells- respond to chemicals

that are dissolved in saliva

Taste buds- receptor sites for tastes.

Most are on the tongue. Some are on the

roof of the mouth and cheeks

Papillae- on the sides of this structure is

where taste buds are found

How do you

Taste?

http://www.cleanvideosearch.com/media/action/yt/watch?videoId=FSHGucgnvLUhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=FSHGucgnvLUhttp://www.pbs.org/wgbh/nova/sciencenow/0404/01.htmlhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=FSHGucgnvLUhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=FSHGucgnvLUhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=FSHGucgnvLUhttp://www.pbs.org/wgbh/nova/sciencenow/0404/01.html

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Basic Taste Sensations

Sweet- sugar, OH- groups

Sour- acidic, H+

Umami- meaty or savory

Bitter- alkaloid bases, very few H+ bonds

Salty- metal ionsThe science

Of

Picky Eaters

http://www.pbs.org/wgbh/nova/sciencenow/0404/01.htmlhttp://www.pbs.org/wgbh/nova/sciencenow/0404/01.htmlhttp://www.pbs.org/wgbh/nova/sciencenow/0404/01.htmlhttp://www.pbs.org/wgbh/nova/sciencenow/0404/01.html

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What effects taste?

Temperature

Smell

Texture

Genetics