Chapter 8 Flashcards
(178 cards)
1
Q
5th sense
A
equilibrium, housed in the ear
2
Q
Of all the sensory receptors, what % are in the eyes?
A
70%
3
Q
The accessory structures of the eye include the
A
extrinsic eye muscle
eyelids
conjunctiva
lacrimal apparatus
4
Q
Anteriorly eyes are protected by
A
eyelids
5
Q
Eyelids meet at the
A
medial and lateral commissure
6
Q
The space between the eyelids in an open eye
A
palpebral fissure
7
Q
Glands that produce an oily secretion that lubricates the eye
A
Tarsal gland
8
Q
Modified sweat glands
A
Ciliary glands, lies between the eyelashes
9
Q
Lines the eyelids and covers part of the outer surface of the eyeball
A
Conjunctiva
10
Q
Conjunctiva secrets?
What does it do?
A
Mucus, which helps to lubricate the eyeball and keep it moist
11
Q
Inflammation of conjunctiva
A
conjunctivitis
results in reddened, irritated eyes.
12
Q
Pinkeye
A
caused by bacteria or virus
highly contagious
13
Q
Located above the lateral end of each eye
A
lacrimal glands
14
Q
The tears flush across the eyeball into the; then into the; and finally into the
A
Lacrimal canaliculi
lacrimal sac
nasolacrimal duct
15
Q
Lacrimal secretion contains
A
mucus
antibodies
lysozyme
16
Q
An enzyme that destroys bacteria
A
lysozyme
17
Q
Causes congestion and sniffles
A
When lacrimal secretion increases substantially, tears spill over the eyelids and fill the nasal cavities, causing congestion and the sniffles.
18
Q
How many extrinsic or external eye muscles are attached to the outer surface of each eye
A
6
19
Q
What makes it possible for eyes to follow a moving object
A
extrinsic or external eye muscles
20
Q
Role of eyelids
A
to protect the eyes
21
Q
structure of the eye that forms tears
A
Lacrimal gland
22
Q
what are tears?
A
dilute saline solution that contains lysozyme and antibodies
23
Q
visual role of the external eye muscles?
A
direct the eyeball towards whatever you wish to see
24
Q
eye itself commonly called
A
eyeball, is a hollow sphere
25
The interior of the eyeball is filled with fluids called
humors, that help to maintain its shape
26
The main focusing apparatus of the eye
lens
27
Lateral rectus
moves eye laterally
28
Medial rectus
moves eye medially
29
Superior rectus
Elevates eye and turns it medially
30
Inferior rectus
Depresses eye and turns it medially
31
Inferior oblique
Elevates eye and turns it laterally
32
Superior oblique
Depresses eye and turns it laterally
33
Outermost layer of the eye
Fibrous layer
34
Fibrous layer consists of the protective; transport
sclera
| cornea
35
"white of the eye"
The sclera, thick, glistening white connective tissue
36
Cornea is well supplied with
nerve endings, most are pain fibers
37
Most exposed part of the eye and the most vulnerable to damage
cornea
38
The only part of the body that is transplanted from one person to another without the worry of rejection
cornea
39
cornea has no
blood vessels, beyond the reach of the immune system
40
Middle layer of the eyeball
Vascular layer
41
3 regions of vascular layer
Choroid
Ciliary body
iris
42
A blood rich nutritive tunic that contains a dark pigment
choroid
43
choroid is attached by 2 smooth muscle
ciliary body and iris
44
The pigmented iris has a rounded opening
pupil, through which the light passes through
45
Innermost layer of the eye
sensory layer
46
The outer pigmented layer of retina is composed of pigmented cells that
absorb light and prevent light from scattering inside the eye
47
Outer pigmented layer of the retina also acts as
phagocytes to remove dead or damaged receptors cells and store vitamin A needed for vision
48
Describe optic disc
The photoreceptor cells are distributed over the entire retina, except where the optic nerve leaves the eyeball. This area is called the optic disc
49
Another name for optic disc
blind spot
50
When light from an object is focused on the optic disk
the object disappears from our view and we cannot see it
51
Rods allow us to see in
gray tones in dim light and they provide our peripheral vision
52
Anything that interferes with rod function hinders our ability to see at night, a condition called
night blindness
53
Cause of night blindness?
prolonged vitamin A deficiency
54
Vitamin A is one of the building blocks
of the pigments of the photoreceptor cells need to respond to light
55
Allows us to see in color
Cones
56
densest in the center of the retina and decrease in number toward the retinal edge
cones
57
A tiny pit that contains only cones
foveacentralis, greatest visual acuity
58
Lack of all 3 cone type results in total
color blindness
59
Lack of one cone type leads to
partial blindness
60
sex linked condition
color blindness, occurs exclusively in men
61
Light entering the eye is focused on the retina by
lens
62
Lens become hard and opaque as we age, causes vision to become hazy and distorted
Cartaracts
63
The lens divides the eye into 2 segments
```
Anterior segment (aqueous humor)
Posterior segment (vitreous humor)
```
64
Helps prevent the eyeball from collapsing inward by reinforcing it internally
vitreous humor
65
FUnctions of aqueous humor
- maintain intraocular pressure
| - provide nutrients for the avascular lens and cornea
66
Aqueous humor is reabsorbed into the venous blood through the
scleral venous sinus or canal of schlemm
67
Common cause of blindness in the elderly
glaucoma
68
Used to measure the intraocular pressure
tonometer
69
Instrument that illuminates the interior of the eye ball, allowing retina, optic disc and internal of the eyeball to be examined
ophthalmoscope
70
examination of the interior of the eye can reveal
diabetes, arteriosclerosis and degeneration of the optic nerve and retina
71
When light passes from one substance to another substance that has a different density, its
speed changes and its rays are bent or refracted
72
Refractive or bending, power of the cornea and humors is
constant
73
The resting eye is set for
distant vision
74
Light from a close object tends to
scatter and to diverge or spread out
75
Ability of the eye to focus specifically for close objects
accommodation
76
The image formed on the retina as a result of the light bending activity of the lends is a
real image
77
Loss of the same side of the visual field of both eyes
Hemianopia
78
Hemianopia results from
damage to the visual cortex on one side only
79
What are necessary for proper eye function
internal and external eye muscles
80
Internal muscles are controlled by
autonomic nervous system
81
Rectus and oblique muscles are
external muscles
82
The external muscles control
eye movements and make it possible to follow moving objects
83
Reflexive movement of the eyes medially when we view close objects
Convergence
84
Photopupillary reflex
When the eyes are suddenly exposed to bright light, the pupils immediately constrict
85
Pupils constrict reflexively when we view close objects
accommodation pupillary reflex
86
What are the refractory media of the eye?
cornea, aqueous humor, lens and vitrous humor
87
What must be stirred to stimulate the receptors of the ear?
fluids
88
Sound vibrations move fluid to stimulate
hearing receptors
89
Receptors sensitive to mechanical pressures such as sound, touch or contractions
mechanoreceptors
90
Information from this helps us to maintain our balance
hearing apparatus
91
3 major areas of the ear
External
middle
Internal
92
Structures that are involved with hearing only
external and middle ear
93
Functions in both equilibrium and hearing
Internal ear
94
External ear is composed of the
auricle and the external acoustic meatus
95
Another name for auricle?
pinna
96
Most people call this ear
auricle or pina
97
Describe auricle
shell shaped structure surrounding the auditory canal opening.
98
The function of auricle in human
is generally lost
99
Describe external acoustic meatus
S short, narrow chamber carved into the temporal bone of the skull
100
Another name of external acoustic meatus
auditory canal
101
In External acoustic meatus's skin lined walls
| What does it secrete?
Ceruminous glands
waxy yellow cerumen or earwax
102
Function of carumen or earwax?
Provides a sticky trap for foreign bodies and repels insects
103
Sound waves entering the auditory canal eventually hit the
tympanic membrane or eardrum
104
The canal ends at
the eardrum which separates the external from the middle ear
105
Another name for middle ear
tympanic cavity
106
Describe middle ear
small air filled, mucosa lined cavity within the temporal bone
107
Middle ear is flanked by
eardrum
| bony wall with 2 openings, oval and round window
108
Runs obliquely downward to link the middle ear cavity with the throat and mucosa lining
Pharyngotympanic tube or auditory tube
109
Inflammation of the middle ear
otitis media
110
otitis media
common result of a soar throat, especially in children, whose pharyngotympanic tubes run more horizontally
111
What is required when large amounts of fluid or pus accumulate in the cavity?
an emergency myringotomy
112
Not a good idea to feed infants when they are lying flat?
The more horizontal course of the pharyngotympanic tube
113
Inner ear is a maze of bony chambers called the
bony or osseous labyrinth
114
3 subdivisions of the bony osseous labyrinth
peasized cochlea
vestibule
semicircular canals
115
the bony labyrinth is filled with a plasmalike fliud called?
| Suspended in it?
perilymph
Membranous labyrinth?
116
Describe membranous labyrinth
a system of membrane sacs that more or less follows the shape of the bony labyrinth
117
membranous labyrinth contains a thicker fliud called
endolymph
118
Which structures of the ear transmit sound vibrations from the eardrum to the oval window?
The ossicles
119
Does not see hear or feel
equilibrium sense
120
equilibrium respond to what?
head movements
121
the equilibrium receptors of the inner ear, collectively called the
vestibular apparatus
122
vestibular apparatus can be divided into
static equilibrium
| dynamic equilibrium
123
Maculae
receptors within the membrane sacs of the vestibule
124
maculae are essential to our sense of
static equilibrium
125
macula help us to
keep the head erect
126
jelly like mass studded with otoliths
otolithic membrane
| tine stones made of calcium salts
127
A division of cranial nerve VII
vestibular nerve
128
dyanatic equilibrium receptors are found and what does it respond to?
in the semicircular canals
| respond to angular or rotatory movements of the head rather than to straight like movements
129
Semicircular canals are orients in
3 planes of space
130
A swollen region at the base of each membranous semicircular canal
ampulla
131
A receptor region within the ampulla
crista ampullaris or crista
132
Crista consists of a tuft of hair cells covered with a gelatinous cap called the
cupula
133
Bending of the cupula in the opposite direction reduces
impulse regeneration
134
what sense do the vestibule and semicircular canals serve?
balance or equilibrium
135
The hair cells that function as hearing receptors are located in
Spiral organ of Corli
136
The chambers above and below the cochlear duct contain
perilymph
137
protects photoreceptors
photopupillary reflex
138
ciliary body brings about the
lens bulge
139
circular muscles of the iris produce the
accommodation pupillary reflex
140
function of maculae
report on changes in the position of the head in space with respect to the pull of gravity when the body is not moving
141
helps us to keep our head erect
maculae
142
within the membrane sacs of the vestibules are receptors called
maculae
143
Each macula is a patch of receptor hair cells with their hairs embedded in the
otolithic membrane
144
dynamic equilibrium receptors are found in
semicircular canals
145
dynamic equilibrium respond to
angular or rotatory movements of the head rather than to straight like movements
146
swollen region at the base of each membranous semicircular canal
ampulla
147
within ampulla is a receptor region called
crista ampullaris
148
responsible for dynamic and static equilibrium
receptors of the semicircular canals and vestibules
149
The hair cells that function as hearing receptors are located in
Spiral organ of Corti
150
chambers above and below the cochlear duct contains
perilymph
151
used to diagnose ear problems
tuning fork or audiometry testing
152
types of deafness
conduction and sensorineural
153
conduction deafness results when
something interferes with the conduction of sound vibrations to the fluids of the inner ear. Build up of ear wax
154
fusion of the ossicles
otosclerosis
155
causes of conduction deafness
otosclerosis, ruptured eardrum and otitis media
156
sensorineural deafness occurs when
there is degeneration or damage to the receptor cells in the spiral organ of Corti, to the cochlear nerve or to neurons of the auditory cortex
157
sensorineural deafness often results from
listening to loud sounds
158
serious pathology of the inner ear
Meniere's syndrome
159
cause of Meniere's syndrome
degeneration of cranial nerve 8, arteriosclerosis and increased pressure of the inner ear fliuds
160
in Meniere's syndrome, what occurs?
progressive deafness
161
sensation of spinning
vertigo
162
becomes inflated and swollen during cold or nasal inflammation
lacrimal mucosa
163
lens is attached by a suspensory ligaments called
ciliary zonule
164
electrical signals pass from the photoreceptors via a 2 neuron chain
bipolar cells and ganglion
165
most common partial color blindness
red or green receptors
166
genes regulating color vision are on
X (female) sex chromosome
167
vitreous segment is filled with a gel like substance called
vitreous humor or vitreous body
168
aqueous humor is located at the
junction of the schlera and cornea
169
posterior wall of the eye
fundus
170
at the optic chiasma
the fibers from the media side of each eye cross over to the opposite side of the brain
171
runs to the occupital lobe of the brain
optic radiation
172
reading requires
photopupillary reflex and accommodation pupillary reflex
173
muscles of the ciliary body
bring about the lens bulge
174
circular muscles of the iris produce
accommodation pupillary reflex
175
pharyngotypanic tubes can be opened by
yawning
176
smallest bones in the body
ossicles
177
function of ossicles
transmit the vibratory motion of the eardrum to the fluids of the inner ear
178
chemical substances must be dissolved in aqueous solution to
excite the receptors for smell and taste
