-Its the transparent structure located behind the conjunctiva.

-It's thick and curved so it refracts light that passes through it.   

-not as Transparent

-Blue is blocked

-light gets scattered more, Glare- seeing bright areas in the wrong places.

-gets flatter so it can't refract light as well

-more difficult to see closer objects. 

    -Increase Astigmatism- irregular curvature of cornea.  Light doesn't get focused right.

-sensitivity to pain is diminish 

-Hole in the center of hte iris

-Allows light to enter rear region of eye.

-muscle cells in iris control size of pupil.  controlled by ANS

What changes do aged Pupils have?

Strength of muscle cells decreses

-Collagen in iris get stiffer and thicker

-Size of pupil diminishes with each passing year.  Starts @ 20.

-can't react as fast to changing light. 

Behind hte Cornea.  Shaped like a cd .

-gives eye color.

-controls size of pupil 

not as strong.

collagen fibers are thicker and stiffer

can't react as fast 

Transparent

refract light alot.

very elastic.  

behind iris and pupil. 

Four of them:

1) Not as transparent.  Begins in 30's

2)Forming of Opacities-opaque spots in the periphery.  If formed in center of eyes then they're called Cataracts.  

3) Can't refract light well.

    Accumulation of damange proteins and formation of abnormal ones

4) Decrease in flexibility/elasticity

    accomodation increases.   

Liquid that fills the cavity in the eye behind the lens!

-composed of a soft gell.

makes an outward pressure on the eye.  makes hte curve.   

1) Rods - light

2) cones - color 

The thin layer that lines the rear portion of the inner cavity of hte eye. 

Consists of the Sensory Retina and the Pigmented epithelium 

sensitive to color

three types:

red, blue and green.

not very sensitive to light.

are very sensitive to light!

only see in black and white.

This is why in dark rooms you do not see any color.

Rods lengthen

get beint into irregular shapes

result is can't see as well in dim light. 

Beginning at 40 they decrese in lenght and in number.

gradual drop in ability to see in detail and in color. 

Conjunctiva

Cornea

Aqueous Humor

Lens

Vitreous Humor 

Opacity that forms in the center of the lens.

Very cloudy and makes it hard to see.

Chemical changes in lens cause cloudiness

Limited visual acuity 

Retinal degeneration

occurs when the flow of vitreous humor out of the eye becomes blocked

This leads to increased eye pressure.

leaves dark spots in field of view.

Optic nerve damage from pressure in eye blocking blood supply

Diabetes is a risk factor for glaucoma.

steals vision slowly and irreversably

air puff tests quick way to test for it 

Cones shorten/lost   Rods lenghten/bend

Iris isn't as elastic/less light can enter eye

UV light causes lens yellowing

Cataracts

Lens isn't as elastic-poorer near vision

retinal degeneration

Glaucoma

Macular (central) degeneration-smoking risk factor

 Retinal detachment via trauma or diabetes mellitus

Occurs when central part of retina (macular) degenerates

Main cause of vision loss in elderly

Comes in two forms: Dry and Wet

Wet is rare and needs immediate medical attention

Smoking is a major risk factor 

two parts:

Pinna- visible part

ear canal 

thin flexible membrane covering the inner end of the ear canal

vibrated by sound passing through ear canal 

tiny bones in the middle ear:

1)Hammer (malleus)

2)Anvil (incus)

3)Strirrup (stapes) 

specalized organs that relay information to nervous system

associated with hair cells in the cochlea 

Snail shape structure inside inner ear

contains Organ of Corti 

Vibration of ossicles initiates pulse waves that stimulate ____________ associated with hair cells in the ___________.

Eustachian tubes

equilibrate pressure

mucus drainage 

provide orientation input through vestibular nerve

sense movement and position of fluid in the canals

very important for balance.

detect motion in 3d 

found in cochlea

important for auditory

contains hair cells 

Presbycusis-can't hear as well

loss of spatial orientation-dizziness

ear drum thicker and less sensitive

can't hear high pitch noises

impairment in speech processing -can't be helped by hearing aids

Tinnitus

earwax gets sticker and plugs ears 

Presbycusis

decreased ability to hear

affects 40% of those over 75 years old; more in men

cumulative damage from loud noises

leads to problems responding to loud sounds

can be helped with hearing aids 

perception of sounds not present (ringing)

several causes:

obstructions, infections, neural disfunction 

moving organism parts (locomotion and manipulation)

Moving substances from place to place (swallowing-pooping, blood pumping, gland excretion, breathing, birthing)

structural integrity,

hair raising

eye movement

body language

vocal language

dan's mom 

1) Cardiac Muscle

2) Smooth Muscle

3)Skeletal Muscle 

found in heart

striated 

found within organs in many body systems

Ex: Susan's vagina 

moves the body

attached to bones

more than 600 muscles 

Sarcolemma spreads impulse through cell via the _________ to the _________ ________.

the membrane of the endoplasmic reticulum within muscle cells are arranged in the form of lacy tubes that extend over the length of hte cell.

regulate the movement of calcium ions needed for contraction 

1) cellular ATP

2)creatine phosphate and glycogen

3) sarcomeres

4) Mitochondria

5) overall cell thickness 

Growth hormone

Testosterone

DHEA