Special Senses Flashcards
(110 cards)
1
Q
_ percent of all sensory receptors are in the eyes
A
70 %
2
Q
each eye has over _ nerve fibers
A
a million
3
Q
most of the eye is enclosed in _
A
a bony orbit
4
Q
a cushion of _ surrounds most of the eye
A
fat
5
Q
_ meet at the medial & lateral commissure (_)
A
eyelids, (canthus)
6
Q
_ are tarsal glands that produce an oily secretion that lubricates the eye
A
eyelashes
7
Q
_ is a membrane that lines the eyelids
A
conjunctiva
8
Q
_ connects to the outer surface of the eye
A
conjunctiva
9
Q
_ secretes mucus to lubricate the eye & keep it moist
A
conjunctiva
10
Q
_= lacrimal gland + ducts
A
lacrimal appartatus
11
Q
_ produces lacrimal fluid; situated on the lateral aspect of each eye
A
lacrimal gland
12
Q
_- drain lacrimal fluid from eyes medially
A
lacrimal caniliculi
13
Q
_- provides passage of lacrimal fluid towards nasal cavity
A
lacrimal sac
14
Q
_- empties lacrimal fluid into the nasal cavity
A
nasolacrimal duct
15
Q
protects, moistens, & lubricates the eye
A
lacrimal apparatus
16
Q
empties into the nasal cavity
A
lacrimal apparatus
17
Q
Tears are a.k.a…
A
lacrimal secretions
18
Q
Lacrimal secretions contain: (4 things)
A
mucus, antibodies, dilute salt solution, lysozyme
19
Q
an enzyme that destroys bacteria
A
lysozyme
20
Q
How many muscles attach to the outer surface of the eye?
A
6 muscles
21
Q
extrinsic eye muscles produce what?
A
produce eye movements
22
Q
the 3 layers that form the wall of the eyeball
A
Fibrous layer (outside), Vascular layer (middle), Sensory layer (inside)
23
Q
white connective tissue area of eye
A
sclera
24
Q
seen anteriorly as the ‘white of the eye’
A
sclera
25
transparent, central anterior portion of eye
cornea
26
allows for light to pass through
cornea
27
repairs itself easily
cornea
28
the only human tissue that can be transplanted without fear of rejection
cornea
29
a blood-rich nutritive layer in the posterior of the eye
choroid
30
pigments prevents light from scattering
choroid
31
modified anteriorly into 2 structures
vascular layer
32
smooth muscle attached to lens
ciliary body
33
regulates amount of light entering eye
iris
34
pigmented layer that gives eye color
iris
35
rounded opening in the iris
pupil
36
2 layers of the retina
outer pigmented layer & inner neural layer
37
which layer contains receptor cells (photoreceptors)
sensory layer
38
what are the 2 receptor cells?
rods & cones
39
sclera & cornea are in which layer?
fibrous layer
40
choroid, ciliary body, iris, & pupil are in which layer?
vascular layer
41
retina, rods & cones are in which layer?
sensory layer
42
signals pass from photoreceptors via a _?
a two-neuron chain
43
signals pass from the photoreceptors via a _, in which layer?
sensory layer
44
which 2 neurons are a part of the 2 neuron chain in the sensory layer?
bipolar neurons, ganglion cells
45
signals leave the retina toward the _ and through the _
toward the brain and through the optic nerve
46
where the optic nerve leaves the eyeball
optic disc (blind spot)
47
cannot see images focused on the _
optic disc
48
neurons of the retina & vision are in which layer?
sensory layer
49
most are found towards the edges of the retina
rods
50
allow dim light vision & peripheral vision
rods
51
all perception is in gray tones
rods
52
allow for detailed color vision
cones
53
densest in the center of the retina
cones
54
lateral to blind spot
fovea centralis
55
area of the retina with only cones
fovea centralis
56
visual acuity (sharpest vision) is here
fovea centralis
57
no photoreceptor cells are at the _
optic disc
58
biconvex crystal-like structure
lens
59
held in place by a suspensory ligament attached to the ciliary body
lens
60
anterior to the lens
anterior (aqueous) segment (chamber)
61
contains aqueous humor
anterior segment
62
anterior chamber aka...
aqueous chamber
63
posterior to the lens
posterior (vitreous) segment (chamber)
64
contains vitreous humor
posterior segment
65
posterior segment aka...
vitreous chamber
66
a way to get nutrients to the cells that are constantly regenerating
aqueous humor
67
watery fluids found bw lens & cornea
aqueous humor
68
similar to blood plasma
aqueous humor
69
helps maintain intraocular pressure *
aqueous humor & vitreous humor
70
aqueous humor is a part of which segment?
anterior segment
71
provides nutrients for the lens & cornea *
aqueous humor
72
reabsorbed into venous blood through the scleral venous sinus, or canal of Schlemm
aqueous humor
73
gel-like substance posterior to the lens
vitreous humor
74
vitreous humor is a part of which segment?
posterior segment
75
prevents the eye from collapsing
vitreous humor
76
light must be focused to a point on the _ for optimal vision
retina
77
the eye is set for _ vision
distance vision
78
distance vision is about how many feet?
over 20 feet away
79
the lens must change shape to focus on closer objects (less than 20 feet away), what is this called?
accomodation
80
images formed on the retina are called:
real images
81
what is reversed from left to right, upside down, & smaller than the object?
real images
82
location where the optic nerves cross
optic chiasma
83
fibers from the medial side of each eye cross over to the opposite side of the brain, what is this called?
optic chiasma
84
contain fibers from the lateral side of the eye on the same side & the medial side of the opposite eye
optic tracts
85
name an eye reflex
photopupillary reflex
86
internal muscles are controlled by which system?
the autonomic nervous system
87
bright light causes pupils to constrict through the action of which 3 muscles?
radial, circular, & ciliary muscles
88
in response to focusing on a near object, then looking at distant object (and vice versa)
accommodation (reflex)
89
_ muscles control eye movement to follow objects
external muscles
90
viewing close objects causes _
convergence (eyes moving medially)
91
eye focuses images on the retina properly
emmetropia
92
Myopia is _sighted
nearsighted
93
distant objects are blurry, what is this called?
myopia
94
light from those objects fails to reach the retina & are focused in front of it
myopia
95
results from an eyeball that is too long
myopia
96
hyperopia is _sighted
farsighted
97
near objects appear blurry while distant objects are clear
hyperopia
98
distant objects are focused behind the retina
hyperopia
99
results from an eyeball that is too short or from a "lazy lens"
hyperopia
100
images are blurry, results from focusing as lines, not points, on the retina due to unequal curvatures of the cornea or lens
astigmatism
101
inhibited rod function that hinders the ability to see at night
night blindness
102
genetic conditions that result in the inability to see certain colors
color blindness
103
due to the lack of 1 type of cone
(partial) color blindness
104
when lens becomes hard & opaque, our vision becomes lazy & distorted
cataracts
105
can cause blindness due to increasing pressure within the eye
glaucoma
106
loss of the same side of the visual field of both eyes; results from damage to the visual cortex on one side only
hemianopia
107
instrument used to illuminate the interior of the eyeball
ophthalmoscope
108
can detect diabetes, arteriosclerosis, degeneration of the optic nerve & retina
ophthalmoscope
109
night blindness, color blindness, & cataracts are all what?
homeostatic imbalances of the eyes
110
glaucoma, & hemianopia are both what?
homeostatic imbalances of the eyes
