The Eye and How It Works pt 1

Question 1

What is the name of the opening between the upper and lower eyelids?

Answer 1

palpebral fissure

Question 2

What is the name of the muscle that lifts open the upper eye lid?

Answer 2

levator palpebrae superiors

Question 3

What is the thick layer of connective tissue that protects the eye and is located in the upper eye lid?

Answer 3

tarsus

Question 4

What is the function of the eyelid?

Answer 4

protects the eye from injury and spreads tears over the eye

Question 5

What is the triangular space on the sides of the cornea when the eyes are open called?

Answer 5

canthi - lateral canthus (outside of eye) and medial canthus (inside of eye)

Question 6

Purpose of eyelids (2)

Answer 6

Protect the eye from injury and excessive light

Question 7

The inside corner of the eye where eye boogers are found. It is modified skin that contains sweat and oil glands with fine cilia.

Answer 7

caruncle

Question 8

Round muscle that goes all the way around the eye that helps the eye close.

Answer 8

orbicularis oculi

Question 9

Three places where tears are formed

Answer 9

lacrimal gland, goblet cells, meibomian glands

Question 10

Small hole near the caruncle that drains tears

Answer 10

punctum

Question 11

small tube between punctum and lacrimal sac

Answer 11

canaliculi (canaliculus - plural)

Question 12

Three functions of tears

Answer 12

forms a smooth refractive surface on the corneal epithelium, maintains a moist environment for the corneal epithelium, carries oxygen to the cornea

Question 13

Tear Flow (3)

Answer 13

punctum -> canaliculus -> lacrimal sac

Question 14

The opaque “white” of the eye.

Answer 14

sclera

Question 15

What is sclera made of?

Answer 15

connective tissue - makes the eye strong to prevent penetration and protect the eye. It also allows passage of nerves and blood.

Question 16

Where the optic nerve goes through the sclera.

Answer 16

lamina cribrosa

Question 17

Part of sclera that is the vascular section. It has connective and elastic tissue to allow the eye to have some give and movement.

Answer 17

episclera

Question 18

mucous membrane that covers the sclera. It is very thin like saran wrap and is continuous from the eyeball to the lid.

Answer 18

conjunctiva

Question 19

2 parts of the conjunctiva

Answer 19

palpebral (on the lids itself) and the bulbar (on the eyeball)

Question 20

Purpose of the conjunctiva

Answer 20

defend and repair the cornea from scratches, wounds and infections.
Catches microorganisms

Question 21

The junctional bay created when the two portions of the conjunctiva meet

Answer 21

fornix

Question 22

What is the conjunctiva made up of?

Answer 22

secretory elements from blood vessels (nutrients, antibodies & leukocytes)
cellular- secretes mucous and oil

Question 23

Transparent, clear, shiny area at the front of the eye.

Answer 23

cornea

Question 24

Details about cornea (3)

Answer 24

• fully developed by age 2
• thickness is maintained
• convex

Question 25

The 1mm transitional zone between cornea and conjunctiva

Answer 25

limbus

Question 26

5 layers of the cornea

Answer 26

epithelium Bowman's layer stroma Descemet's membrane endothelium

Question 27

Epithelium (4)

Answer 27

-Outer part of the cornea (touches tears) -5-7 cells thick (50 microns) - barrier and refractive surface - rapid regeneration without scarring

Question 28

Bowman's Layer (2)

Answer 28

-acellular -10 microns thick

Question 29

Stroma (2)

Answer 29

-Thickest layer of cornea (makes up 90% of the corneal thickness) - 78% water

Question 30

Descemet's Membrane (2)

Answer 30

-3-12 microns thick -basement membrane (attaches to something)

Question 31

Endothelim (2)

Answer 31

-4-6 microns thick -500,000 cells that you are born with

Question 32

What provides nourishment to cornea (3)

Answer 32

- plexus of fine capillaries at limbus - tear film - Aqueous humor (clear fluid between cornea and iris) **there are NO blood vessels in cornea

Question 33

Uvea (3)

Answer 33

iris, cilliary body, choroid **High blood vessel/blood flow area

Question 34

very outermost part of uvea

Answer 34

iris

Question 35

Iris (4)

Answer 35

- very outermost part of uvea - central circular aperature (pupil) - many ridges and furrows - 2 muscles (sphincter - closes, dialator - opens)

Question 36

Ciliary Body

Answer 36

-behind iris - connected to sclera - cilliary processes (plump with many folds, 2/5 mm thick, products aqueous humor) - zonular fibers (fine ligamentous fibers that attach to lens)

Question 37

what connects to cilliary body to control shape of lens

Answer 37

zonular fibers

Question 38

What lies between the retina and sclera that is a vascular structure that provides nourishment to retina?

Answer 38

choroid

Question 39

Structures of "the angle" (5)

Answer 39

- root of iris - anterior surface of ciliary body - scleral spur - canal of Schlemm - trabecular meshwork

Question 40

4 steps of "the angle"

Answer 40

*aqueous hum0r through trabecular meshwork - trabecular meshwork contains pores that takes the aqueous to schlemm's canal - aqueous then leaves the eye through aqueous veins that penetrate the sclera *Obstruction leads to glaucoma

Question 41

lens shape

Answer 41

biconvex (front and back bow outward)

Question 42

lens diameter

Answer 42

9-10 mm (about 1 cm)

Question 43

lens equator

Answer 43

attachment for zonular fibers

Question 44

lens capsule

Answer 44

transparent, elastic envelope that hardens with age

Question 45

lens nucleus (2)

Answer 45

-develops in our 30s -The central portion of the len

Question 46

lens cortex

Answer 46

outer lens fibers

Question 47

The lens onion effect

Answer 47

The lens keeps growing until it gets too big. The center grows outward and we never lose a cell This happens in our 40s and prevents us from being able to focus on close up objects.

Question 48

What makes up 2/3 of the interior volume of the eye?

Answer 48

vitreous humor

Question 49

what is vitreous humor

Answer 49

99% water - jelly like substance, thick and viscous

Question 50

What is vitreous humor made up of?

Answer 50

matrix of collagen fibers hyaluronic acid

Question 51

This is anchors at the ora serrata, optic nerve and various points on the retina

Answer 51

vitreous humor

Question 52

the serrated junction between the retina and the ciliary body

Answer 52

ora serrata

Question 52

What causes floaters in the eye?

Answer 52

The collagen fibers in the vitreous humor break away, condense and lose transparency

Question 53

This part of the eye is an extension of the brain

Answer 53

retina

Question 54

How many layers does the retina have?

Answer 54

10

Question 55

This photoreceptor is responsible for seeing in dim light, is often associated with poor vision as well as action vision and there are about 125,000,000 of them.

Answer 55

rods

Question 56

This photoreceptor is responsible for color vision, fine detailed vision and there are about 6,000,000 of them.

Answer 56

cones

Question 57

The part of the retina where all fine detail comes from

Answer 57

central

Question 58

This part of the retina has a concentrated area of cones and damage to it dramatically reduces acuity.

Answer 58

macula lutea (central)

Question 59

This part of the retina is where most of the rods are located and damage to it causes night blindness

Answer 59

peripheral

Question 60

This sends nutrients to the retina and attaches to the choroid

Answer 60

pigment epithelium

Question 61

The part of the eye at the posterior of the globe that sends visual impulses from the retina to the brain. It has 1,000,000 axons.

Answer 61

optic nerve

Question 62

This supplies 1/3 of blood to the eye and has arteries and veins that branch in an arc patterns

Answer 62

optic nerve

Question 63

Where does optic nerve enter globe?

Answer 63

through the sclera in the lamina cribrosa (the basement of the physiological cup)

Question 64

This keeps what each eye sees on the left side together and what each eye sees on the ride side together.

Answer 64

optic chiasm

Question 65

Where the nasal fibers of one eye have joined with the temporal fibers of the other.

Answer 65

optic tract (the portion after the optic chiasm after the crossover happens)

Question 66

The relay station where fibers spread out in a fan shaped manner and extend to the parietal and temporal lobes.

Answer 66

Lateral Geniculate Body

Question 67

The area of the occipital lobe where conscious recognition occurs.

Answer 67

visual striate area

Question 68

the six muscles that move the eyeball

Answer 68

superior oblique inferior oblique superior rectus inferior rectus medial rectus lateral rectus

Question 69

This muscle adducts the eye to move it horizontally towards the nose

Answer 69

medial rectus

Question 70

This muscle abducts the eye to move it horizontally to the outside

Answer 70

lateral rectus

Question 71

This muscle moves the eye up

Answer 71

superior rectus

Question 72

This muscle moves the eye down

Answer 72

inferior rectus

Question 73

This muscle causes intorsion, moving the eye up and inward

Answer 73

superior oblique

Question 74

This muscle causes extorsion, moving the eye away from and down from the nose

Answer 74

inferior oblique