The Eye

Question 1

structures of the eye

Answer 1

• eyebrow/eyelid/eyelashes
• conjunctiva
• lacrimal gland
• nasolacrimal duct
• extrinsic muscles of the eye

Question 2

eyebrow/eyelash function

Answer 2

-protects eye from dust and foreign objects

Question 3

eyelid function

Answer 3

-protects eye from foreign objects

Question 4

eyebrow/eyelid/eyelashes function

Answer 4

• keeps eye moist

- contains a small amount of cartilage

Question 5

conjunctiva structure

Answer 5

-thin mucus membrane

Question 6

conjunctiva location

Answer 6

• on the inner surface (on the back part) of the eyelid and sclera
• doesn’t cover the cornea

Question 7

sclera location

Answer 7

-white part of the anterior surface of the eyeball

Question 8

conjunctivitis**

Answer 8

• pink eye

- can be inflamed and diffusely reddened sure to viral infection

Question 9

lacrimal gland

Answer 9

• upper cornea of the orbit
• secretes tears with parth of flow
  
  • ->upper lateral portion of eye to inferior medial part

Question 10

what nerve controls the lacrimal gland?

Answer 10

-facial nerve (CN VII)

Question 11

nasolacrimal duct

Answer 11

-passes from medial corner of the orbit and lateral nose to the nasal cavity

Question 12

extrinsic muscles of the eye

Answer 12

• these muscles allow for superior, inferior, medial lateral rotational
• controlled by skeletal muscles

Question 13

eyeball layers

Answer 13

• outermost
• middle
• innermost

Question 14

outermost eye components

Answer 14

• sclera

- cornea

Question 15

outermost eye: sclera location

Answer 15

• called the white of eye
• tough outermost layer of CT
• continuous with dura mater

Question 16

outermost eye: sclera function

Answer 16

-protects the sensitive inner structure and gives shape

Question 17

outermost eye: cornea location

Answer 17

• transparent anterior portion that bulges

- covers iris, pupils and anterior chamlar

Question 18

is the cornea vascular or avascular?

Answer 18

• avascular

- oxygen diffuses from vessels in sclera

Question 19

is the middle eye vascular or avascular?

Answer 19

vascular

Question 20

middle eye components

Answer 20

• choroid
• ciliary body
• iris

Question 21

middle eye: choroid function

Answer 21

-combines blood vessels supplying interior of eyeball

Question 22

middle eye: ciliary body

Answer 22

-contains muscle which changes shape of the lens

Question 23

middle eye: iris

Answer 23

• colored/pigmented smooth muscle

- regulates size of pupil to protect retina from strong light

Question 24

what is the innermost eye called?

Answer 24

-retina (has 10 layers)

Question 25

retina structure

Answer 25

- one outer pigment layer | - ->black in color which absorbs light rays

Question 26

retina components

Answer 26

- pigmented layer | - nervous layer

Question 27

retina pigmented layer

Answer 27

-only one layer

Question 28

retina nervous layer

Answer 28

- nine layers | - 3 of them involved in conduction of image

Question 29

which nervous layers are involved in the conduction of image?

Answer 29

- rods (dim light) and cones (color) - bipolar cells - ganglion cells

Question 30

what are the steps in the visual response pathway?

Answer 30

- the stimulation of the photoreceptor cells of the retina(rods & cones) as light reached them - impulses generated from retina are passed onto optic nerve and then to visual centers in cortex(occipital lobe)

Question 31

optic nerve composition/location

Answer 31

- composed of axons from ganglion cell layer of retina (forms optic nerve and passes back towards brain) - extends from posterior side of eye

Question 32

optic nerve function

Answer 32

-transmits impulse to visual pathway

Question 33

fovea centralis

Answer 33

-area of most acute vision/sharpest vision

Question 34

optic disc

Answer 34

- aka "blind spot" - where optic nerve enters with blood vessels - no cells of retina here**

Question 35

visual pathway path

Answer 35

retina--> optic nerve--> optic chiasm--> optic tract --> lateral geniculate (thalamus) --> optic radiations --> visual (occipital cortex)

Question 36

lens

Answer 36

- changes shape to help bend light rays | - brings them into sharp focus on the retina

Question 37

lens characteristics

Answer 37

- crystal clear/transparent - contains elastic CT - composed of protein

Question 38

what is the len's adaptability called?

Answer 38

-accomodation

Question 39

what happens if there's excess protein in the lens

Answer 39

- the lens becomes cloudy | - cloudy lens is called a cataract

Question 40

cavities components

Answer 40

- anterior cavity (anterior to lens) | - posterior cavity (posterior to lens)

Question 41

the anterior cavity is composed of what two chambers?

Answer 41

- anterior chamber | - posterior chamber

Question 42

the anterior cavity's chambers contain what?

Answer 42

-aqueous humor

Question 43

aqueous humor

Answer 43

- a clear liquid produced by "ciliary body" | - continually produced

Question 44

glaucoma

Answer 44

-if the aqueous humor isn't drained through channels, the increases in pressure causes blindness (this is called glaucoma)

Question 45

posterior cavity

Answer 45

- aka vitreous chamber | - contains vitreous humor

Question 46

vitreous humor composition

Answer 46

-clear, gelatinous substance produced during embryonic development

Question 47

vitreous humor function

Answer 47

-maintains pressure and shape of eyeball

Question 48

how is the eye supplied with blood?

Answer 48

- vessels enter with optic nerve coming off branches of internal carotid artery - vessels in choroid layer come in laterally

Question 49

what needs to happen for optimum vision?

Answer 49

- light must be focused on the retina - amount of light reaching retina must be regulated - all controlled by ANS

Question 50

what does the eye do for optimal vision?

Answer 50

- change in shape of lens (aka accommodation) - alteration in size of lens - convergence

Question 51

accomodation overall functional components

Answer 51

- focuses on a far object | - focuses on a nearby object

Question 52

how does the eye focus on a far object?

Answer 52

- ciliary muscles relax | - lens move back and stretched out by suspensory ligaments (bc lens is thin)

Question 53

how does the eye focus on a close object?

Answer 53

- ciliary muscles tense up (get larger) | - lens move forward

Question 54

what is convergence?

Answer 54

-eyeballs rotate medially for better focusing of light when viewing an object close up

Question 55

altering size of pupils overall functional components

Answer 55

- dilation | - constriction

Question 56

dilation

Answer 56

- muscle that runs radially (in smooth muscle) | - controlled by oculomotor nerve

Question 57

constriction

Answer 57

- muscle turns in circular direction (in smooth muscle) | - controlled by oculomotor nerve