Anatomy_Key Terms_Ch16 Flashcards
1
Q
taste buds
A
house taste receptors, in the mucosa of the mouth and pharynx, mostly on the surface of the tongue, a few others occur on the posterior region of the palate, on the inner surface of the cheeks, on the posterior wall of the pharynx, and on the epiglottis
2
Q
papillae
A
peglike projections of the tongue mucosa in which most taste buds occur
3
Q
fungiform papillae
A
scattered over the entire surface of the tongue, the taste buds are on the apical surface, small
4
Q
vallate papillae
A
arranged in an inverted V near the back of the tongue, large, taste buds occupy the epithelium on the sides
5
Q
foliate papilla
A
on the posterolateral surface of the tongue, the taste buds are in the side walls
6
Q
gustatory hairs
A
project from the gustatory epithelial cells and extend through a taste pore to the surface of the epithelium
7
Q
gustatory epithelial cells and basal epithelial cells
A
two major cell types contained in each taste bud
8
Q
gustatory pathway
A
taste information reaches the brain stem and cerebral cortex through the _
9
Q
olfactory epithelium
A
covers the superior nasal concha and the superior part of the nasal septum and is bathed by swirling air that has been inhaled into the nasal cavity
10
Q
olfactory sensory neurons
A
bipolar neurons contained in the speudostratified columnar (olfactory) epithelium
11
Q
supporting epithelial cells
A
columnar cells surrounding the olfactory sensory neurons
12
Q
olfactory stem cells
A
short undifferentiated neuroepithelial cells that continually form new olfactory sensory neurons, at the base of the epithelium
13
Q
olfactory cilia
A
”"”hairs””, act as the receptive structures for smell by binding odor molecules to receptor proteins located in the plasma membrane of the cilia”
14
Q
filaments of the olfactory nerve
A
nerve bundles which penetrate the cribrifirm plate of the ethmoid bone and enter the overlying olfactory bulb of the forebrain
15
Q
olfactory bulb
A
“the olfactory nerve axons branch profusely and synapse with neurons called mitral cells in complex synaptic clusters called glomeruli (““balls of yarn””)”
16
Q
uncinate fits
A
olfactory hallucinations in which they perceive some imaginary odor
17
Q
eye
A
visual organ, a spherical structure with a diameter of about 2.5 cm
18
Q
eyebrows
A
coarse hairs in the skin on the superciliary arches, shade the eyes from sunlight and prevent perspiration running down the forehead from reaching the eyes
19
Q
eyelids
A
aka palpebrae, thin, skin-covered folds supported internally by connective tissue structures called tarsal plates
20
Q
palpebral fissure
A
eye slit, separates the upper and lower eye lids
21
Q
lacrimal caruncle
A
”"”a bit of flesh””, medial angle of the eyelids contains a reddish elevation called the _”
22
Q
tarsal plates
A
give the eyelids their curved shape and serve as attachment sites for the eye-closing muscle, the orbicularis oculi
23
Q
levator palpebrae superioris
A
”"”lifter of the upper eyelid””, skeletal muscle that voluntarily opens the eye”
24
Q
eyelashes
A
projecting from the free margin of each eyelid, richly innervated by nerve endings
25
tarsal glands
modified sebaceous glands embedded in the tarsal plates
26
chalazion
"""swelling"", infection of a tarsal gland results in an unsightly but usually painless cyst"
27
sty
infection of the ciliary glands causes a painful inflammation
28
conjunctiva
"""joined together"", a transparent mucous membrane that covers the inner surfaces of the eyelids as the palpebral conjunctiva and folds back over the anterior surface of the eye as the bulbar conjunctiva"
29
conjunctival sac
when an eye is closed, the slitlike space that forms between the eye surface and the eyelids
30
conjunctivitis
inflammation of the conjunctiva
31
pinkeye
a highly contagious form of conjunctivitis caused by bacteria or viruses
32
lacrimal apparatus
"""tear"", keeps the surface of the eye moist with lacrimal fluid (tears), consists of a gland and ducts that drain the lacrimal fluid into the nasal cavity"
33
lacrimal punctum
"""puncture"", each lid contains a tiny opening (_) at the medial angle which empties into a small tube, the lacrimal canaliculus"
34
lacrimal sac
"from the lacrimal canaliculus (""small canal""), the fluid drains into the _ in the medial orbital wall"
35
nasolacrimal duct
fluid inters the _ from the lacrimal sac, then empties into the nasal cavity at the inferior nasal meatus
36
lysozyme
an enzyme that destroys bacteria
37
extrinsic eye muscles
(outer), originate from the walls of the orbit and insert onto the outer surface of the eyeball, control the movement of each eye and hold the eyes in the orbits
38
common tendinous ring
or anular ring, at th posterior point of the orbit, origin point for the four rectus (straight) extrinsic eye muscles
39
trochlea
"""pulley"", ligamentous sling suspended from the frontal bone in the anteromedial part of the orbit roof"
40
superior oblique muscle
"originates posteriorly near the common tendinous ring, runs anteriorly along the medial orbit wall, and then loops through the trochlea, then its tendon runs posteriorly and inserts on the eye's posterolateral surface"
41
inferior oblique muscle
originates on the anteromedial part of the orbit floor and angles back to insert on the posterolateral part of the eye
42
anterior pole
most anterior point of the eyeball
43
posterior pole
most posterior point of the eyeball
44
fibrous layer
most external layer of the external wall of the eye, consists of dense connective tissue arranged into two different regions: sclera and cornea
45
sclera
"""hard"", opaque white, hard, forms the posterior 5/6 of the fibrous layer, protects the eyeball and provides shape and a sturdy anchoring site for the extrinsic eye muscles"
46
cornea
anterior sixth of the fibrous layer, transparent, through which light enters the eye
47
vascular layer
middle coat of the eyeball, has three parts: the choroid, the ciliary body, and the iris
48
choroid
"""membrane"", highly vascular, darkly pigmented membrane that forms the posterior five-sixths of the vascular layer"
49
ciliary body
postteriorly continous with the choroid, a thickened ring of tissue that encircles the lens
50
ciliary muscle
smooth muscle that acts to focus the lens
51
ciliary processes
nearest the lens, the posterior surface of the ciliary body is thrown into radiating folds called _
52
ciliary zonule
halo of fine fibrils that extends from around the entire circumference of the lens and attaches to the ciliary processes
53
iris
"""rainbow"", visible, colored part of the eye, lies between the cornea and lens, and its base attaches to the ciliary body"
54
pupil
round central opening of the iris, allows light to enter the eye
55
pupillary light reflex
constriction of the pupils that occurs when a bright light is flashed in the eye is a protective response
56
inner layer
contains the retina (thin pigmented layer and a far thicker neural layer) and the optic nerve
57
pigmented layer
outer thin layer of the retina which lies against the choraid, single layer of flat-to-columnar melanocyes, functions to absorb light and prevent it from scattering within the eye
58
neural layer
thicker inner layer of the retina is a sheet of nervous tissue that contains the light-sensitive photoreceptor cells
59
optic nerve
axons from the ganglion cells run along the internal surface of the retina and converge posteriorly to form the _ which runs from the eye to the brain
60
photoreceptor cells
signal the bipolar cells when stimulated by light, are of two types (rod cells and cone cells), considered neurons but resemble tall epithelial cells turned upside down
61
rod cells
more sensitive to light and permit vision in dim light, provide neither sharp images nor color vision
62
cone cells
operate best in bright light and enable high-acuity color vision
63
ora serrata
"""sawtoothed mouth"", junction where the neural layer ends at the posterior margin of the ciliary body"
64
macula lutea
"""yellow spot"", lying precisely at the eye's posterior pole"
65
fovea centralis
"""central pit"", tiny pit at the center of the macula lutea, contains only cones and provides maximal visual acuity"
66
optic disc
a few milimeters medial to the fovea, a circular elevation where the axons of ganglion cells converge to exit the eye as the optic nerve, called the blind spot because it lacks photoreceptors
67
central artery and vein of the retina
supply the inner two-thirds of the retina, enter and leave the eye by running through the center of the optic nerve
68
posterior segment
lens and its halolike ciliary zonule divide the eye into posterior and anterior segments, filled with the clear vitreous humor
69
vitreous humor
(glassy), a jellylike substance that contains fine fibrils of collagen and a ground substance that binds termendous amounts of water
70
anterior segment
divided into an anterior chamber between the cornea and iris and a posterior cahmber between thi iris and lens, filled with aqueous humor
71
aqueous humor
a clear fluid sumilar to blood plasma, renewed continously and is in constant motion
72
scleral venous sinus
large vessel at the corneoscleral junction which returns the aqueous humor to the blood
73
lens
thick, transparent, biconvex disc that changes shape to allow precise focusing of light on the retina, enclosed in a thin elastic capsule and is held in place posterior to the iris by its ciliary zonule
74
lens epithelium
confined to the anterior surface, consists of cuboidal cells
75
lens fibers
form the bulk of the lens, contain no nuclei and few organelles, transparent due to precisely folded proteins
76
refractory media
light-bending parts of the eye, the cornea, the lens, and the humors (most to least bending)
77
accomodation
adjustability that allows the eye to focus on nearby objects
78
visual pathway
visual information travels to the cerbral cortex trhough the main _
79
optic tract
axons continue in the optic tract after the axons from the medial half of each eye decussate
80
lateral geniculate nucleus of the thalamus
most of the axons from the optic tracts go to the _ where they synapse with thalamic neurons
81
optic radiation
axons of those neurons then poject through the internal capsule to form the _ of fibers in the cerebral white matter
82
pretectal nuclei
mediate the pupillary light reflexes
83
suprachiasmatic nucleus
"the ""timer"" that runs our daily biorhythms and requires visual input to keep it in synchrony with the daylight-darkness cycle"
84
optic vesicles
paired lateral outgrouwths from the dienchephalon appearing by week 4 of the embryo
85
optic cups
double-layered _ formed from the hollow optic vesicles indenting
86
optic stalks
medial part of the outgrowths form the basis of the optic nerves (week 4)
87
lens placode
once a growing optic vesicle reaches the overyling surface ectoderm, it signals the ectoderm to thicken and form a _
88
lens vesicle
by week 5, the lens placode has invaginated to form a _
89
retinopathy of prematurity
a visual imparment that affects many infnts born so prematurely that they need to receive oxygen in an oxygen tent; new blood vessels start to grow extensively within the eyes, then hemorrhage, leading to retinal detachment and then blindness
90
trachoma
"""rough growth"", highly contagious infection of the conjunctiva and cornea, transmitted by hand-to-eye contact, by flies that go from eye to eye, or by placing contaminated objects in or near the eye"
91
presbycusis
"""old hearing"", gradual loss of hearing with age"
92
external ear
consists of the auricle and the external acoustic meatus
93
auricle
aka pinna, is the shell-shaped projection that surrounds the opening of the external acoustic meatus, mostly cartilage
94
helix (ear)
(rim), part of the auricle consisting of elastic cartilage covered with skin
95
lobule (ear)
"""earlobe"", fleshy, dangling part of the auricle, lacks supporting cartilage"
96
tympanic membrane
(drum) or eardrum, thin, translucent boundary between the external ad middle ears, shaped like a flattened cone, the apex of which points medially into the middle ear cavity
97
middle ear
aka tympanic cavity, small, air-filled space inside the petrous part of the temporal bone, lined by a thin mucous membrane and shaped like a hockey puck standing on its side, bounded by the tympanic membrane and a wall of bone that separates it from the internal ear
98
epitympanic recess
midlle ear arches upward as the _, its superior boundary is the roof of the petrous portion of the temporal bone
99
mastoid antrum
canal leading to the mastoid air cells in the mastoid process; the posterior wall of the middle ear opens into it
100
pharyngotympanic tube
or auditory tube, links the middle ear to the pharynx; normally closed but can be opening by yawning or swallowing to equalize air pressure
101
auditory ossicles
transmit the vibrations of the eardrum across the cavity to a fluid in the internal ear
102
malleus
hammer, which looks like a club with a knob on top, lateral ossicle
103
incus
anvil, which resembles a tooth with two roots, middle ossicle
104
stapes
which looks like the stirrup of a saddle, medial ossicle, base vibrates aginst the oval window
105
tensor tympani
originates on the cartilage part of the pharyngotympanic tube and inserts on the malleus
106
stapedius
runs from the posterior wall of the middle ear the stapes, contracts (with tensor tympani) reflexively to limit the vibration of the ossicles when assaulted by very loud sounds
107
internal ear
aka labyrinth (maze), complex shape, lies within the thick protective walls of the petrous part of the temporal bone, consists of two main divisions (bony labyrinth and membranous labyrinth)
108
bony labyrinth
cavity in the petrous part of the temporal bone consisting of a system of twisting channels that has three parts: from posterolateral to anteromedial, simicircular canals, vestibule, and cochlea
109
membranous labyrinth
continuous series of membrane-walled sacs and ducts that fit loosely within the bony labyrinth and more or less follow its contours
110
oval window
superior window, base of the stapes vibrates against it, as does the scala vestibuli base
111
round window
inferior window, scala tympani ends at the _ at the base of the cochlea
112
endolymph
"""internal water"", the membranous labyrinth is filled with a clear fluid"
113
perilymph
"""surrounding water"", external to the membranous labyrinth, the bony labyrinth is filled with another clear fluid, continuous with the crebrospinal fluid that fills the subarachnoid space"
114
cochlea
"""snail shell"", spiraling chamber located inferiorly in the bony labyrinth"
115
modiolus
pillar of bone around which the cochlea coils about two and a half turns
116
osseous spiral lamina
spiraling projection of bone on the modiolus
117
cochlear nerve
cholear division of the vestibulocochlear nerve (VIII), running through the bony core of the modiolus
118
scala vestibula and scala tympani
(scala=ladder), two perilymph-filled chambers of the bony labyrinth
119
helicotrema
"""the hole in the spiral"", scala vestibuli and scala tympani are continuous with each other at the apex of the cochlea in a region called the _"
120
cochlear duct
or scala media, the part of the membranous labyrinth that contains the sensory receptors for hearing
121
vestibular membrane
"""roof"" of the cochlear duct, separating it from the scala vestibuli"
122
basilar membrane
sheet of fibers attached to the osseous spiral lamina which together make up of the floor of the cochlear duct
123
spiral organ
supported by the basilar mebrane; the receptor epithelium for hearing
124
inner hair cells
columnar supporting cells of the tall epithelium spiral organ, receptor cells, three sterocilia arranged linearly
125
outer hair cells
columnar supporting cells of the tall epithelium spiral organ, three rows of receptor cells, stereocilia form a W pattern
126
tectorial membrane
"""roofing membrane"", gel-like _ has sterocilia embedded in it"
127
spiral ganlion
house cell bodies of bipolar neurons, in the osseous spiral lamina and modiolus
128
vestibule (ear)
central cavity of the bony labyrinth, lies just medial to the middle ear, and the oval window is in its lateral bony wall
129
utricle
"""leather bag"", egg-shaped part of the membranous labyrinth suspended within the vestibul's perilymph, continuous with the semicircular ducts"
130
saccule
"""little sac"", egg-shape part of the membranous labyrinth, suspended within the vestibule's perilympth, continuous with the cochlear duct"
131
macula
"""spot"" spot of sensory epithelium housed on each of utricle and saccule, contain receptor cells that monitor the position of the head when the head is held still (static equalibrium)"
132
vestibular nerve
vestibular division of the vestibulocochlear nerve (VIII)
133
hair cells
receptors that synapse with sensory fibers of the vestibular nerve, each has many sterocilia (long microvilli) and a single kinocilium (a true cilium) protruding from its apex
134
otolith membrane
overlying jellylike disc in with the tips of the stiff hairs (hair cells) are embedded
135
otoliths
"""ear stones"", heavy crystals of calcium carbonate contained in the otolith membrane"
136
semicircular canals
lie posterior and lateral to the vestibule, each of three lies in one of the three planes of space
137
ampulla
"""flask"", expansion at one end of the semicircular canals"
138
anterior and posterior semicircular canals
lie in vertical planes at right angles to each other
139
lateral semicircular canal
lies almost horizontally
140
semicircular duct
snaking through each semicircular canal is part of the membranous labyrinth, the _
141
membranous ampulla
swelling in each semicurcular duct within the corresponding bony ampulla
142
crista ampullaris
"""crest of the ampulla"", small crest housed in each membranous ampulla, contain the receptor cells that measure rotational (angular) acceleration of the head"
143
ampullary cupula
tall, jellylike mass that resembles a pointed cap, into which the receptor hair cells project
144
auditory pathway
ascending, transmits auditory information primarily from the cochlear receptors of the inner hair cells to the cerbral cortex
145
cochlear nuclei
impulses first pass through the cochlear nerve to the _ in the medulla
146
superior olivary nuclei
from the medulla, some neurons project to the _ which lie at the junction of the medulla and pons
147
lateral lemniscus
a fiber tract, axons ascend in the _ after the medulla/pons junction
148
inferior collicus
auditory reflex center in the midbrain, from the lateral lemniscus to the _
149
medial geniculate nucleus of the thalamus
inferior collicus projects to the _; axons of the thalamic neurons then project to the primary auditory cortex which provides conscious awareness of sound
150
primary auditory cortex
receives impulses from both ears since not all the fibers of the auditory pathway cross over to the other side of the brain
151
equilibrium pathway
transmits information on the position and movements of the head via the vestibular nerve to the brain stem
152
otic placode
thickening on the surface ectoderm (week 4) that begins to form the internal ear
153
otic pit
otic placode invaginates to form the _
154
otic vesicle
edges of the otic pit fuse to form the _ which detaches from the surface epithelium
155
branchial groove
an indentation of the surface ectoderm, from which the external acoustic meatus differentiates
156
motion sickness
common disorder of equilibrium in which particular motions lead to nausea and vomiting
157
"Meniere's syndrome"
membranous balyrinth is apparetly distorted by excessive amounts of endolymph; equilibrium so disturbed that standing is nearly impossible, transiet but repeated attacks of vertigo, nausea, and vomiting, and tinnitus, roaring or buzzing sounds in the ears such that hearing is impaired and perhaps ultimately lost
158
conduction deafness
occurs when sound vibrations cannot be conducted to the internal ear
159
sensorineural deafness
results from damage to the hair cells or to any part of the auditory pathway to the brain
160
cochlear implants
for complete sensorineural deafness, placed in the temporal bone, convert sound energy into electrical signals and deliver these signals directly to the cochlear nerve fibers
161
house taste receptors, in the mucosa of the mouth and pharynx, mostly on the surface of the tongue, a few others occur on the posterior region of the palate, on the inner surface of the cheeks, on the posterior wall of the pharynx, and on the epiglottis
taste buds
162
peglike projections of the tongue mucosa in which most taste buds occur
papillae
163
scattered over the entire surface of the tongue, the taste buds are on the apical surface, small
fungiform papillae
164
arranged in an inverted V near the back of the tongue, large, taste buds occupy the epithelium on the sides
vallate papillae
165
on the posterolateral surface of the tongue, the taste buds are in the side walls
foliate papilla
166
project from the gustatory epithelial cells and extend through a taste pore to the surface of the epithelium
gustatory hairs
167
two major cell types contained in each taste bud
gustatory epithelial cells and basal epithelial cells
168
taste information reaches the brain stem and cerebral cortex through the _
gustatory pathway
169
covers the superior nasal concha and the superior part of the nasal septum and is bathed by swirling air that has been inhaled into the nasal cavity
olfactory epithelium
170
bipolar neurons contained in the speudostratified columnar (olfactory) epithelium
olfactory sensory neurons
171
columnar cells surrounding the olfactory sensory neurons
supporting epithelial cells
172
short undifferentiated neuroepithelial cells that continually form new olfactory sensory neurons, at the base of the epithelium
olfactory stem cells
173
"""hairs"", act as the receptive structures for smell by binding odor molecules to receptor proteins located in the plasma membrane of the cilia"
olfactory cilia
174
nerve bundles which penetrate the cribrifirm plate of the ethmoid bone and enter the overlying olfactory bulb of the forebrain
filaments of the olfactory nerve
175
"the olfactory nerve axons branch profusely and synapse with neurons called mitral cells in complex synaptic clusters called glomeruli (""balls of yarn"")"
olfactory bulb
176
olfactory hallucinations in which they perceive some imaginary odor
uncinate fits
177
visual organ, a spherical structure with a diameter of about 2.5 cm
eye
178
coarse hairs in the skin on the superciliary arches, shade the eyes from sunlight and prevent perspiration running down the forehead from reaching the eyes
eyebrows
179
aka palpebrae, thin, skin-covered folds supported internally by connective tissue structures called tarsal plates
eyelids
180
eye slit, separates the upper and lower eye lids
palpebral fissure
181
"""a bit of flesh"", medial angle of the eyelids contains a reddish elevation called the _"
lacrimal caruncle
182
give the eyelids their curved shape and serve as attachment sites for the eye-closing muscle, the orbicularis oculi
tarsal plates
183
"""lifter of the upper eyelid"", skeletal muscle that voluntarily opens the eye"
levator palpebrae superioris
184
projecting from the free margin of each eyelid, richly innervated by nerve endings
eyelashes
185
modified sebaceous glands embedded in the tarsal plates
tarsal glands
186
"""swelling"", infection of a tarsal gland results in an unsightly but usually painless cyst"
chalazion
187
infection of the ciliary glands causes a painful inflammation
sty
188
"""joined together"", a transparent mucous membrane that covers the inner surfaces of the eyelids as the palpebral conjunctiva and folds back over the anterior surface of the eye as the bulbar conjunctiva"
conjunctiva
189
when an eye is closed, the slitlike space that forms between the eye surface and the eyelids
conjunctival sac
190
inflammation of the conjunctiva
conjunctivitis
191
a highly contagious form of conjunctivitis caused by bacteria or viruses
pinkeye
192
"""tear"", keeps the surface of the eye moist with lacrimal fluid (tears), consists of a gland and ducts that drain the lacrimal fluid into the nasal cavity"
lacrimal apparatus
193
"""puncture"", each lid contains a tiny opening (_) at the medial angle which empties into a small tube, the lacrimal canaliculus"
lacrimal punctum
194
"from the lacrimal canaliculus (""small canal""), the fluid drains into the _ in the medial orbital wall"
lacrimal sac
195
fluid inters the _ from the lacrimal sac, then empties into the nasal cavity at the inferior nasal meatus
nasolacrimal duct
196
an enzyme that destroys bacteria
lysozyme
197
(outer), originate from the walls of the orbit and insert onto the outer surface of the eyeball, control the movement of each eye and hold the eyes in the orbits
extrinsic eye muscles
198
or anular ring, at th posterior point of the orbit, origin point for the four rectus (straight) extrinsic eye muscles
common tendinous ring
199
"""pulley"", ligamentous sling suspended from the frontal bone in the anteromedial part of the orbit roof"
trochlea
200
"originates posteriorly near the common tendinous ring, runs anteriorly along the medial orbit wall, and then loops through the trochlea, then its tendon runs posteriorly and inserts on the eye's posterolateral surface"
superior oblique muscle
201
originates on the anteromedial part of the orbit floor and angles back to insert on the posterolateral part of the eye
inferior oblique muscle
202
most anterior point of the eyeball
anterior pole
203
most posterior point of the eyeball
posterior pole
204
most external layer of the external wall of the eye, consists of dense connective tissue arranged into two different regions: sclera and cornea
fibrous layer
205
"""hard"", opaque white, hard, forms the posterior 5/6 of the fibrous layer, protects the eyeball and provides shape and a sturdy anchoring site for the extrinsic eye muscles"
sclera
206
anterior sixth of the fibrous layer, transparent, through which light enters the eye
cornea
207
middle coat of the eyeball, has three parts: the choroid, the ciliary body, and the iris
vascular layer
208
"""membrane"", highly vascular, darkly pigmented membrane that forms the posterior five-sixths of the vascular layer"
choroid
209
postteriorly continous with the choroid, a thickened ring of tissue that encircles the lens
ciliary body
210
smooth muscle that acts to focus the lens
ciliary muscle
211
nearest the lens, the posterior surface of the ciliary body is thrown into radiating folds called _
ciliary processes
212
halo of fine fibrils that extends from around the entire circumference of the lens and attaches to the ciliary processes
ciliary zonule
213
"""rainbow"", visible, colored part of the eye, lies between the cornea and lens, and its base attaches to the ciliary body"
iris
214
round central opening of the iris, allows light to enter the eye
pupil
215
constriction of the pupils that occurs when a bright light is flashed in the eye is a protective response
pupillary light reflex
216
contains the retina (thin pigmented layer and a far thicker neural layer) and the optic nerve
inner layer
217
outer thin layer of the retina which lies against the choraid, single layer of flat-to-columnar melanocyes, functions to absorb light and prevent it from scattering within the eye
pigmented layer
218
thicker inner layer of the retina is a sheet of nervous tissue that contains the light-sensitive photoreceptor cells
neural layer
219
axons from the ganglion cells run along the internal surface of the retina and converge posteriorly to form the _ which runs from the eye to the brain
optic nerve
220
signal the bipolar cells when stimulated by light, are of two types (rod cells and cone cells), considered neurons but resemble tall epithelial cells turned upside down
photoreceptor cells
221
more sensitive to light and permit vision in dim light, provide neither sharp images nor color vision
rod cells
222
operate best in bright light and enable high-acuity color vision
cone cells
223
"""sawtoothed mouth"", junction where the neural layer ends at the posterior margin of the ciliary body"
ora serrata
224
"""yellow spot"", lying precisely at the eye's posterior pole"
macula lutea
225
"""central pit"", tiny pit at the center of the macula lutea, contains only cones and provides maximal visual acuity"
fovea centralis
226
a few milimeters medial to the fovea, a circular elevation where the axons of ganglion cells converge to exit the eye as the optic nerve, called the blind spot because it lacks photoreceptors
optic disc
227
supply the inner two-thirds of the retina, enter and leave the eye by running through the center of the optic nerve
central artery and vein of the retina
228
lens and its halolike ciliary zonule divide the eye into posterior and anterior segments, filled with the clear vitreous humor
posterior segment
229
(glassy), a jellylike substance that contains fine fibrils of collagen and a ground substance that binds termendous amounts of water
vitreous humor
230
divided into an anterior chamber between the cornea and iris and a posterior cahmber between thi iris and lens, filled with aqueous humor
anterior segment
231
a clear fluid sumilar to blood plasma, renewed continously and is in constant motion
aqueous humor
232
large vessel at the corneoscleral junction which returns the aqueous humor to the blood
scleral venous sinus
233
thick, transparent, biconvex disc that changes shape to allow precise focusing of light on the retina, enclosed in a thin elastic capsule and is held in place posterior to the iris by its ciliary zonule
lens
234
confined to the anterior surface, consists of cuboidal cells
lens epithelium
235
form the bulk of the lens, contain no nuclei and few organelles, transparent due to precisely folded proteins
lens fibers
236
light-bending parts of the eye, the cornea, the lens, and the humors (most to least bending)
refractory media
237
adjustability that allows the eye to focus on nearby objects
accomodation
238
visual information travels to the cerbral cortex trhough the main _
visual pathway
239
axons continue in the optic tract after the axons from the medial half of each eye decussate
optic tract
240
most of the axons from the optic tracts go to the _ where they synapse with thalamic neurons
lateral geniculate nucleus of the thalamus
241
axons of those neurons then poject through the internal capsule to form the _ of fibers in the cerebral white matter
optic radiation
242
mediate the pupillary light reflexes
pretectal nuclei
243
"the ""timer"" that runs our daily biorhythms and requires visual input to keep it in synchrony with the daylight-darkness cycle"
suprachiasmatic nucleus
244
paired lateral outgrouwths from the dienchephalon appearing by week 4 of the embryo
optic vesicles
245
double-layered _ formed from the hollow optic vesicles indenting
optic cups
246
medial part of the outgrowths form the basis of the optic nerves (week 4)
optic stalks
247
once a growing optic vesicle reaches the overyling surface ectoderm, it signals the ectoderm to thicken and form a _
lens placode
248
by week 5, the lens placode has invaginated to form a _
lens vesicle
249
a visual imparment that affects many infnts born so prematurely that they need to receive oxygen in an oxygen tent; new blood vessels start to grow extensively within the eyes, then hemorrhage, leading to retinal detachment and then blindness
retinopathy of prematurity
250
"""rough growth"", highly contagious infection of the conjunctiva and cornea, transmitted by hand-to-eye contact, by flies that go from eye to eye, or by placing contaminated objects in or near the eye"
trachoma
251
"""old hearing"", gradual loss of hearing with age"
presbycusis
252
consists of the auricle and the external acoustic meatus
external ear
253
aka pinna, is the shell-shaped projection that surrounds the opening of the external acoustic meatus, mostly cartilage
auricle
254
(rim), part of the auricle consisting of elastic cartilage covered with skin
helix (ear)
255
"""earlobe"", fleshy, dangling part of the auricle, lacks supporting cartilage"
lobule (ear)
256
(drum) or eardrum, thin, translucent boundary between the external ad middle ears, shaped like a flattened cone, the apex of which points medially into the middle ear cavity
tympanic membrane
257
aka tympanic cavity, small, air-filled space inside the petrous part of the temporal bone, lined by a thin mucous membrane and shaped like a hockey puck standing on its side, bounded by the tympanic membrane and a wall of bone that separates it from the internal ear
middle ear
258
midlle ear arches upward as the _, its superior boundary is the roof of the petrous portion of the temporal bone
epitympanic recess
259
canal leading to the mastoid air cells in the mastoid process; the posterior wall of the middle ear opens into it
mastoid antrum
260
or auditory tube, links the middle ear to the pharynx; normally closed but can be opening by yawning or swallowing to equalize air pressure
pharyngotympanic tube
261
transmit the vibrations of the eardrum across the cavity to a fluid in the internal ear
auditory ossicles
262
hammer, which looks like a club with a knob on top, lateral ossicle
malleus
263
anvil, which resembles a tooth with two roots, middle ossicle
incus
264
which looks like the stirrup of a saddle, medial ossicle, base vibrates aginst the oval window
stapes
265
originates on the cartilage part of the pharyngotympanic tube and inserts on the malleus
tensor tympani
266
runs from the posterior wall of the middle ear the stapes, contracts (with tensor tympani) reflexively to limit the vibration of the ossicles when assaulted by very loud sounds
stapedius
267
aka labyrinth (maze), complex shape, lies within the thick protective walls of the petrous part of the temporal bone, consists of two main divisions (bony labyrinth and membranous labyrinth)
internal ear
268
cavity in the petrous part of the temporal bone consisting of a system of twisting channels that has three parts: from posterolateral to anteromedial, simicircular canals, vestibule, and cochlea
bony labyrinth
269
continuous series of membrane-walled sacs and ducts that fit loosely within the bony labyrinth and more or less follow its contours
membranous labyrinth
270
superior window, base of the stapes vibrates against it, as does the scala vestibuli base
oval window
271
inferior window, scala tympani ends at the _ at the base of the cochlea
round window
272
"""internal water"", the membranous labyrinth is filled with a clear fluid"
endolymph
273
"""surrounding water"", external to the membranous labyrinth, the bony labyrinth is filled with another clear fluid, continuous with the crebrospinal fluid that fills the subarachnoid space"
perilymph
274
"""snail shell"", spiraling chamber located inferiorly in the bony labyrinth"
cochlea
275
pillar of bone around which the cochlea coils about two and a half turns
modiolus
276
spiraling projection of bone on the modiolus
osseous spiral lamina
277
cholear division of the vestibulocochlear nerve (VIII), running through the bony core of the modiolus
cochlear nerve
278
(scala=ladder), two perilymph-filled chambers of the bony labyrinth
scala vestibula and scala tympani
279
"""the hole in the spiral"", scala vestibuli and scala tympani are continuous with each other at the apex of the cochlea in a region called the _"
helicotrema
280
or scala media, the part of the membranous labyrinth that contains the sensory receptors for hearing
cochlear duct
281
"""roof"" of the cochlear duct, separating it from the scala vestibuli"
vestibular membrane
282
sheet of fibers attached to the osseous spiral lamina which together make up of the floor of the cochlear duct
basilar membrane
283
supported by the basilar mebrane; the receptor epithelium for hearing
spiral organ
284
columnar supporting cells of the tall epithelium spiral organ, receptor cells, three sterocilia arranged linearly
inner hair cells
285
columnar supporting cells of the tall epithelium spiral organ, three rows of receptor cells, stereocilia form a W pattern
outer hair cells
286
"""roofing membrane"", gel-like _ has sterocilia embedded in it"
tectorial membrane
287
house cell bodies of bipolar neurons, in the osseous spiral lamina and modiolus
spiral ganlion
288
central cavity of the bony labyrinth, lies just medial to the middle ear, and the oval window is in its lateral bony wall
vestibule (ear)
289
"""leather bag"", egg-shaped part of the membranous labyrinth suspended within the vestibul's perilymph, continuous with the semicircular ducts"
utricle
290
"""little sac"", egg-shape part of the membranous labyrinth, suspended within the vestibule's perilympth, continuous with the cochlear duct"
saccule
291
"""spot"" spot of sensory epithelium housed on each of utricle and saccule, contain receptor cells that monitor the position of the head when the head is held still (static equalibrium)"
macula
292
vestibular division of the vestibulocochlear nerve (VIII)
vestibular nerve
293
receptors that synapse with sensory fibers of the vestibular nerve, each has many sterocilia (long microvilli) and a single kinocilium (a true cilium) protruding from its apex
hair cells
294
overlying jellylike disc in with the tips of the stiff hairs (hair cells) are embedded
otolith membrane
295
"""ear stones"", heavy crystals of calcium carbonate contained in the otolith membrane"
otoliths
296
lie posterior and lateral to the vestibule, each of three lies in one of the three planes of space
semicircular canals
297
"""flask"", expansion at one end of the semicircular canals"
ampulla
298
lie in vertical planes at right angles to each other
anterior and posterior semicircular canals
299
lies almost horizontally
lateral semicircular canal
300
snaking through each semicircular canal is part of the membranous labyrinth, the _
semicircular duct
301
swelling in each semicurcular duct within the corresponding bony ampulla
membranous ampulla
302
"""crest of the ampulla"", small crest housed in each membranous ampulla, contain the receptor cells that measure rotational (angular) acceleration of the head"
crista ampullaris
303
tall, jellylike mass that resembles a pointed cap, into which the receptor hair cells project
ampullary cupula
304
ascending, transmits auditory information primarily from the cochlear receptors of the inner hair cells to the cerbral cortex
auditory pathway
305
impulses first pass through the cochlear nerve to the _ in the medulla
cochlear nuclei
306
from the medulla, some neurons project to the _ which lie at the junction of the medulla and pons
superior olivary nuclei
307
a fiber tract, axons ascend in the _ after the medulla/pons junction
lateral lemniscus
308
auditory reflex center in the midbrain, from the lateral lemniscus to the _
inferior collicus
309
inferior collicus projects to the _; axons of the thalamic neurons then project to the primary auditory cortex which provides conscious awareness of sound
medial geniculate nucleus of the thalamus
310
receives impulses from both ears since not all the fibers of the auditory pathway cross over to the other side of the brain
primary auditory cortex
311
transmits information on the position and movements of the head via the vestibular nerve to the brain stem
equilibrium pathway
312
thickening on the surface ectoderm (week 4) that begins to form the internal ear
otic placode
313
otic placode invaginates to form the _
otic pit
314
edges of the otic pit fuse to form the _ which detaches from the surface epithelium
otic vesicle
315
an indentation of the surface ectoderm, from which the external acoustic meatus differentiates
branchial groove
316
common disorder of equilibrium in which particular motions lead to nausea and vomiting
motion sickness
317
membranous balyrinth is apparetly distorted by excessive amounts of endolymph; equilibrium so disturbed that standing is nearly impossible, transiet but repeated attacks of vertigo, nausea, and vomiting, and tinnitus, roaring or buzzing sounds in the ears such that hearing is impaired and perhaps ultimately lost
"Meniere's syndrome"
318
occurs when sound vibrations cannot be conducted to the internal ear
conduction deafness
319
results from damage to the hair cells or to any part of the auditory pathway to the brain
sensorineural deafness
320
for complete sensorineural deafness, placed in the temporal bone, convert sound energy into electrical signals and deliver these signals directly to the cochlear nerve fibers
cochlear implants
