EYE Flashcards
1
Q
function of eye
A
-focus light rays on rods and cones
2
Q
structures in the anterior chamber of the eye
A
- aqueous humor
- ciliary body
- canal of schlemn
- cornea
- lens
- pupil
- iris
- conjunctiva
3
Q
3 layers of the eye are (from innermost to outermost)
A
- retina
- choroid
- sclera
4
Q
aqueous humour location
A
-front of lens
5
Q
aqueous humour structure
A
-protein like
6
Q
how often is the aqueous humour drained, made and recycled
A
5x a day
7
Q
where is aqueous humor drained from?
A
canal of schlemn
8
Q
where is aqueous humor produced?
A
ciliary body
9
Q
function of aqueous humor
A
carry nutrients for cornea and lens
10
Q
glaucoma
A
- no drainage of aq humor and the optic nerve is harmed and loses capability to send messages to the brain and BLINDNESS
11
Q
how do you correct glaucoma
A
- surgery
- daily intake of meds
12
Q
which structure is the anterior extension of the sclera and is transparent
A
cornea
13
Q
what structure divides the 2 fluid filled cavities
A
lens
14
Q
function of lens
A
-projects light onto the retina (upside down)
15
Q
what makes the lens translucent
A
-apoptosis during fetal development
16
Q
iris function
A
vary size of pupil which determines how much light can get in (not all the light reaches through)
17
Q
which is the pigment part of the eye
A
the iris
18
Q
which structure in the anterior chamber s the furthest from the aq humor
A
iris
19
Q
pupil is the structure where
A
light enters and can be adjusted by contracting iris muscles
20
Q
which mucous membrane covers the entire eye
A
conjunctiva
21
Q
bacteria + conjunctiva =
A
a lot of puss
22
Q
virus + conjunctiva =
A
- less puss
- can go undetected
- aka conjunctivitis (pink eye)
23
Q
structures in the posterior eye
A
- vitreous humor
- sclera
- choroid layer
- retina
- optic nerve
- fovea
- macula lutea
- optic discs
24
Q
vitreous humor structure
A
- covered by sclera
- gel-like
25
vitreous humor function
- protect eye
| - maintain shape and structure
26
choroid layer function
- anteriorly from the ciliary body and iris
| - prevents scattering of light rays in eyes
27
what layers of the eye has bv tat nourish the retina
-choroid layer
28
what eye layer make sup the white part of the eye
-sclera
29
function of retina
has photoreceptors
30
optic nerve function
-takes visual pathways to the brain
31
which region of the has the sharpest vision with the greatest acuity ?
fovea
32
does fovea have rods or cones or both
CONES ONLY, + highest concentration of cones
33
where is the macula lutea located
fovea
34
what is the macula lutea
flap of ct that surrounds fovea
35
macula degeneration is aka
donut vision
36
what happens in macula degeneration
-degeneration of sharpest vison, losing photoreceptors
-peripheral vision only
BLINDNESS
37
what eye structure forms the blindspot
optic discs
38
which structure in the eye has no rods and cones
optic discs
39
function of optic discs
-full of bvs which the optic nerve leaves through
40
accommodation meaning
-changing the strength and shape of lens wit the help of suspensory ligaments
41
when are the suspensory ligaments stretched to the max, taut and tight
sympathetic stimulation of ciliary muscles
42
when is the lens flat and why
sympathetic stimulation and for far vision
43
when are the ciliary muscles relaxed
sympathetic stimulation
44
what happens to the suspensory ligaments during parasympathetic stimulation
they are relaxed and weakened
45
what happens to the lens during parasympathetic stimulation
they are rounded
46
when do we need round lens
for near vision
47
CN 3 nerve aka
oculomotor nerve
48
function of cn 3
-change lens shape, pupil muscles, and ciliary muscles
49
which CN is the trochlear nerve
cn 4
50
function of the cn4, trochlear nerve
-movement of extrinsic eye muscles
51
cn 5 aka
trigeminal nerve
52
which nerve is responsible for sensory info for the head and the neck
CN5, trigeminal nerve
53
which nerve controls extrinsic muscles of the eye
- cn 6, Abducens
| - cn4, trochlear
54
cn 7 aka
facial nerve
55
which nerve releases and produces tears
cn 7, facial nerve
56
hyperopia aka
far - sightedness
57
when is the focus behind the retina
-hyperopia
58
how can hyperopia be corrected
convex lenses
59
what is near sightless referred to as
myopia
60
where does the focal point land in myopia
in front of retina
61
how can myopia be fixed
concave lens
62
which seeing problem is the most common
-myopia
63
what is the shape of the eye ball in myopia
too long
64
the lens is too strong in which seeing problem
myopia
65
what causes prebysopia
old age
66
what happens in prebysopia
- lens start to call out
- lose elasticity
- can accommodate for near vision
67
what condition is fixed with reading glasses
prebysopia
68
when is the eyeball too short and the lens is too weak
hyperopia
69
which eye structure is the extension of the CNS
retina
70
retina contains
-modified neurones called rods and cones
71
which photoreceptor is used for night vision
rods
72
what colour do rods see in
-seeing in shades of grey
73
which photoreceptor has low acuity and sensitive
rods
74
location of rods
abundant in peripheral region
75
what photoreceptor absorbs all wavelengths and can't discriminate ?
rods
76
cones are used for seeing in
the day
77
what are the three colour the cones can see in
red, green, blue
78
which colour has the Lowest wavelengths
blue
79
which photoreceptor has high acuity
cones
80
where are the highest amount of cones located
-centre of retina (fovea + macula lulea)
81
Nighttime blindness is caused by the deficiency of
Vit A
82
what's happens with night blindness
- no transduction
| - reduced # of rods
83
what time of the day can one see With night blindness
- during the day
84
which condition is a result of missing or malfunctioning red and green cones
colour blindness
85
opsin structure
outer covering, disc membrane
86
retinal is a
vit A derivatve
87
function of retinal
-light absorbing part of photopigment
88
photopigments def
set that undergoes chemical alterations when activated by light
89
which segment of a photoreceptor is faces the chord layer and contacts rods and cones that can detect light stimulus
outer segment
90
what does the inner segment of a photoreceptor contain
-metabolic parts of a cell
91
outermost layer of the retina is the closet to
the choriod layer
92
which layer of the retina contains photoreceptors
-outermost layer
93
where are bipolar cells found in the Retina layers
middle player
94
which eye cells display graded potential
bipolar cells
95
which cells are found in the inner layer of the retina
ganglion cells
96
ganglion cells function
-form ap and transmit info to brain
97
which cells unite to form the optic nerve (CN2)
ganglion cells
98
synaptic terminal location
closest to eyes interior
| faces bi-polar cells
99
synaptic terminal function
- transmits small graded potential
| - release neurotransmitters
100
when is the concentration of cGMP high
retina in the dark
101
what controls and the opening and closing of Na+ channels
concentration of cGMP
102
how is darkness perceived?
depolarization occurs, inhibitory neurotransmitter is released
103
when is transducin excited
-when Retinal leaves opsin when light hits the retina
104
what is activated when light hits the retina
phosphodiesterase
105
what happens to the cGMP concentration and Na+ when light hits the retina
- Na+ channels close
| - decreased concentration of cGMP
106
what occurs when light hits the Retina
- inhibitory neurotransmitter is not released
- hyperpolarization
- graded potential
- ganglion cells produce ap which goes to the occitpal lobes
- light is perceived
107
visual pathway
optic nerve -> optic chaism -> optic tract -> lateral geniculate body -> optic radiation
108
where is visual info crossed
optic chaism
109
what takes the info to the thalamus
optic tract
110
lateral geniculate body location
thalamus
111
which structure is in the visual cortex
optic radiation
112
which cells allow lateral inhibition
ganglion cells
113
which type of ganglion is responsible for enhancing image
on - centre
114
in which gangion cell does depolarization occur
on-centre
115
what does the off centre ganglion cell allow
periphery vision
116
which ganglion cell inhibits the cells
off- centre
