Chapter 15: The Special Senses Flashcards

1
Q

what is the cornea?

A

transparent area on anterior surface of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the pupil?

A

opening in center of the iris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

function of the pupil

A

transmits light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the conjunctiva?

A

layer of mucous membrane and epithelium that lines the eyelids and anterior eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the tarsal glands?

A

modified sebaceous glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the function of tarsal glands?

A

secretions prevent eyelid from sticking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

conjunctivitis is also known as

A

pinkeye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is conjunctivitis?

A

inflammation of the conjunctiva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

redness of the eye in conjunctivitis is due to __

A

dialation of blood vessels deep in epithelium of conjunctiva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what things can cause conjunctivitis?

A

infection, irritation (physical, chemical, allergic) on conjunctival surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

function of lacrimal gland

A

makes tears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the function of tears?

A

lubricate, nourish, oxygenate and clean the cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

lacrimal gland contains ___ and ___ that attack invading pathogens

A

lysozyme; antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the three tunics (layers) of the eye?

A
  1. outer fibrous
  2. middle vascular
  3. inner
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is contained in the outer layer of the eye?

A

sclera and cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is contained in the middle layer of the eye?

A

iris, choroid, ciliary body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is contained in the inner layer of the eye?

A

retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the 3 functions of the fibrous layer of the eye?

A
  1. support and protect
  2. attachment site for extrinsic eye muscles
  3. curve of cornea focuses light
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

light enters first through the __

A

cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

the vascular layer of the eye contains ___, ___ and ___

A

blood vessels; lymphatic vessels; intrinsic muscles of eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the 4 functions of the vascular layer of the eye?

A
  1. route for blood vessels/lymphatic to eye
  2. regulates amount of light (iris)
  3. secretes / reabsorbs aqueous humour
  4. controls shape of lens (ciliary body) = focus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the iris/

A

coloured part of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

the iris contains __ and __

A

blood vessels and pigment cells (melanocytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

the iris is made of 2 layers of

A

smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the role of the smooth muscle in the iris?

A

contraction changes diameter of pupil to control amount of light entering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the ciliary body?

A

thickened region bulging into interior eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

___ connects ciliary body and lens

A

ring of fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is the choroid?

A

vascular layer under the sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

the choroid has an extensive __ network supplying ___ and __ to the neural layer

A

capillary network; oxygen/nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

function of the outer pigmented layer of the retina

A

absorbs light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

the thick inner neural layer of the retina contains ____

A

photoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what are the 2 types of photoreceptors?

A

rods and cones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

eye cavities are separated by ____

A

lens / ciliary body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

the anterior cavity of the eye extends from __ to __

A

cornea to lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

the anterior cavity contains fluid called __

A

aqueous humor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

the anterior cavity contains 2 chambers ___

A
  1. anterior chamber

2. posterior chamber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

the anterior chamber of the anterior cavity in the eye extends from the ___ to ___

A

cornea to iris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

the posterior chamber in the anterior cavity of the eye extends from ___ to __

A

iris to ciliary body and lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

the posterior cavity is filled with gelatinous ___

A

vitreous body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what is the vitreous humor?

A

fluid part of the vitreous body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what is the ciliary muscle?

A

smooth muscle ring that projects into the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

the aqueous humor circulates within the ___ and passes through the __

A

anterior cavity; pupil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

the aqueous humor is secreted by the epithelial cells of the ____

A

ciliary processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

the aqueous humor diffuses through the ___ to the ___ surface

A

vitreous body; retinal surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

the aqueous humor leaves the eye at the ___

A

scleral venous sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

the aqueous humor flows into veins in the __

A

sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what are the 4 functions of the aqueous humor?

A
  1. transports nutrients and wastes
  2. forms fluid cushion
  3. helps retain eye shape
  4. stabilizes position of the retina
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

the body of the iris is highly __ pigmented ___ tissue

A

vascular; loose connective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

eye colour is determined by genes that influence ___ and ___

A

density/distribution of melanocytes; density of pigmented epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

T/F the cornea is transparent and clear to allow light through

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

the cornea is a dense matrix of multiple layers of __-

A

collagen fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

the cornea is ___ and receives oxygen and nutrients from ___

A

avascular; tears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

what is the primary function of the lens?

A

changes shape to focus image on photoreceptors

54
Q

what is the sclera?

A

the white of the eye

55
Q

what is the sclera made of ?

A

dense fibrous connective tissue + collagen and elastic fibers

56
Q

what are 2 functions of the sclera?

A
  1. stabilizes eye shape during movement

2. insertion for extrinsic eye muscles

57
Q

function of the optic nerve

A

conveys visual information to brain

58
Q

what are 2 functions of the ciliary body?

A
  1. supports lens

2. controls lens shape

59
Q

____ helps resist the urge of the lens to ball up

A

tension in ciliary zonule

60
Q

the retina contains what 4 things?

A
  1. photoreceptors
  2. pigent cells
  3. supporting cells
  4. neurons
61
Q

the two pupillary muscles of the iris are

A
  1. dialator pupillae muscles

2. sphincter pupillae muscles

62
Q

formation of dilator pupillae muscles around pupil

A

extend radially

63
Q

the dilator pupillae muscles are innervated by the ___ nervous system

A

sympathetic

64
Q

formation of sphincter muscles around pupil

A

encircle pupil

65
Q

the sphincter pupillae muscles are innervated by the ___ nervous system

A

parasympathetic

66
Q

what is the macula?

A

patch of retina with lots of photoreceptors

67
Q

the fovea centralis is the central part of the __

A

macula

68
Q

the highest concentration of photoreceptors (sharpest image) is found in the ___

A

fovea centralis

69
Q

explain how light is focused in the eye

A
  1. light is refracted when it comes in through the cornea and again through aqueous humor into lens and is bent towards focal point
70
Q

the focal point is a specific point on the __

A

retina

71
Q

the focal distance of a lens is the distance between the center of __ and its ___

A

lens; focal point

72
Q

the focal distance is determined by two things __ and __

A
  1. distance form object to lens

2. shape of lens

73
Q

T/F the distance from lens to retina can change

A

false

74
Q

eyes focus by changing ___ ( a process called __ )

A

changing shape of the lens; accommodation

75
Q

for close vision; the ciliary muscle _____ (contracts/relaxes) and moves ____ (towards/away) and ____ (increases/decreases tension in ciliary zonule

A

contracts; towards; decreases

76
Q

for distant vision; the cilary muscle ___ and the ciliary zonule ___ on lens

A

relaxes; pulls

77
Q

for close vision, the lens is pulled into a ___ shape

A

spherical

78
Q

the spherical shape of the lens increases __

A

refraction

79
Q

for distant vision, the shape of the lens is __-

A

flattened

80
Q

what is the near point of vision?

A

inner limit of clear vision

81
Q

the near point of vision is determined by __

A

lens elasticity

82
Q

the near point of vision ___ with age

A

increases

83
Q

what is the function of the pigmented layer of the retina

A

prevents visual echoes by absorbing light

84
Q

what is the site of preliminary processing/integration of visual info?

A

neural layer of retina

85
Q

photoreceptors are located closest to the ___ layer

A

pigmented

86
Q

rods are highly ___

A

sensitive

87
Q

the function of rods

A

allow vision in dim light

88
Q

T/F rods can distinguish colour

A

false

89
Q

function of cones

A

colour vision, sharper, clearer images

90
Q

cones require what kind of light?

A

intense

91
Q

rods and cones synapse with ___

A

bipolar cells

92
Q

bipolar cells synapse on ___

A

ganglion cells

93
Q

what is the innermost layer of the retina?

A

ganglion cells

94
Q

axons of ganglionic cells converge at the ___ to form the optic nerve

A

optic disc

95
Q

what is the blind spot?

A

where the optic nerve leaves the eye

96
Q

blood vessels follow the ___ to supply inner neural layers

A

optic nerve

97
Q

cones are most dense at the ___

A

fovea centralis of the macula

98
Q

are there rods located in the fovea centralis?

A

no

99
Q

cone density directly correlated to ___

A

visual acuity

100
Q

maximum density of rods s located at ___

A

periphery

101
Q

the visible light spectrum

A

400-700 nm

102
Q

rods respond to ___ wavelengths

A

blue-green

103
Q

what are the 3 types of cones?

A
  1. blue cones
  2. green cones
  3. red cones
104
Q

what is the most abundant type of cones?

A

red cones

105
Q

if all three cone types are stimulated, what colour do we see?

A

white

106
Q

colour blindness is caused by __

A

nonfunctional or absent cones

107
Q

red-green colour blindness is caused by a lack of what type of cones?

A

red cones

108
Q

describe the visual pathway

A

photoreceptors —> bipolar cells —> ganglion cells

109
Q

the 2 optic nerves reach the diencephalon at the ____

A

optic chiasm

110
Q

from the optic chiasm, continue along the ___

A

optic tracts

111
Q

about half the fibers from the optic nerve go to the ___ nucleus on the ___ side of the brain and the other half to the ___ side

A

lateral geniculate; same side, opposite side

112
Q

what is optic radiation?

A

bundle of projection fibers linking each lateral geniculate body with visual cortex on the same side

113
Q

collaterals from fibers synapsing in lateral geniculate bodies go to subconscious processing centers in the ___ and ___

A

diencephalon and brainstem

114
Q

what is depth perception?

A

ability to judge depth / distance by interpreting 3D relationships

115
Q

depth perception is perceived by comparing ___ within images received by both eyes

A

relative positions of objects

116
Q

T/F images form right and left eyes overlap

A

true

117
Q

emmetropia is ___ vision

A

normal

118
Q

in normal vision; when the ciliary muscle is relaxed and lens flattened, distant image is focused on ___

A

retinal surface

119
Q

myopia is ____ vision

A

nearsightedness

120
Q

in myopia, the focal distance is too ___

A

short

121
Q

in myopia, the image focuses on ___

A

area in front of retina

122
Q

shape of the eyeball that causes myopia

A

too deep (egg-shaped)

123
Q

in myopia, the resting curvature of the eye is too ___

A

great

124
Q

myopia is corrected with ___ lenses

A

diverging / concave

125
Q

what is the function of concave lenses?

A

spreads light rays apart to shift focus onto retina

126
Q

hyperopia is ___ vision

A

farsighted

127
Q

in hyperopia, the focal distance is too __

A

long

128
Q

in hyperopia, the image focuses on __

A

area behind the retina

129
Q

shape of eyeball with hyperopia

A

too flat

130
Q

hyperopia is corrected with ___ lenses

A

converging / convex

131
Q

what is the function of convex lenses?

A

provides additional refraction to focus on retina