Chapter 8 Flashcards
1
Q
Special senses include
A
Smell
Taste
Sight
Hearing
Equilibrium
2
Q
Special sense receptors
A
Large, complex sensory organs (eye and ear)
Localized clusters of receptors (taste buds and olfactory epithelium)
3
Q
70 Percent of all sensory receptors are in
A
Eyes
4
Q
How many nerve fibers in each eye?
A
Over 1 million nerve fibers per eye
5
Q
Accessory structures in eye
A
Extrinsic eye muscles
Eyelids
Conjunctiva
Lacrimal apparatus
6
Q
Extrinsic eye muscles
A
Eye movement
7
Q
Conjunctiva
A
Cover sclera and cornea (connects w/)
Membrane line eyelids & eyeballs
8
Q
Palpebra
A
Eyelid
9
Q
Eyelids meet in
A
Commisure or canthus
10
Q
Lateral commissure
A
Outer corner of eye
11
Q
Medial commissure of eye
A
Inner corner of eye
12
Q
Sclera
A
White part
Covered by conjunctiva
13
Q
Iris
A
Colored part of eye
14
Q
Cornea
A
Clear part of sclera
15
Q
Pupil
A
Dark part of eye
Photons of light pass
16
Q
Meets at medial and lateral commisures
A
Eyelids
17
Q
Eyelashes
A
Prevent injury, keep debris out
18
Q
Tarsal glands
A
Produce oily secretion that lubricates eye
19
Q
Mebum
A
Oily secretion that lubricates eye
20
Q
Ciliary glands located
A
Between eyelashes
21
Q
What secretes mucus to lubricate the eye and keep it moist
A
Conjunctiva
22
Q
Parts of Lacrimal apparatus
A
Lacrimal gland
Ducts
23
Q
Lacrimal gland
A
Lacrimal fluid
On lateral end of each eye
24
Q
Explain how tears drain
A
- Drain across eye into Lacrimal canaliculi
- Lacrimal sac
- Nasolacrimal duct
- Empties into Nasal cavity
25
What is inside tears?
Dilute salt solution
Mucus
Antibodies
Lysozyme (enzyme destroys bacteria)
26
Function of tears
Cleanse
Protect
Moisten
Lubricate eye
27
Extrinsic eye muscles
Attach to outer surface of the eye
Make gross eye movement
28
Name the extrinsic muscles of the eye
Superior, inferior oblique
2 Lateral, superior, inferior rectuses
29
Trochlea
Anchored superior oblique
30
Lateral rectus action
Moves eye laterally
31
Controlling cranial nerve of lateral rectus
VI
Abducens
32
Medial rectus action
Moves eye medially
33
Medial rectus controlled by
III (oculomotor)
34
Superior rectus action
Elevates eye
Turns it medially
35
Superior rectus controlled by
III oculomotor
36
Inferior rectus action
Depresses eye
Turns it medially
37
Inferior rectus controlled by
III oculomotor
38
Inferior oblique action
Elevates eye and turns it laterally
39
Inferior oblique controlling cranial nerve
III oculomotor
40
Superior oblique action
Depresses eye & turns laterally
41
Controlling cranial nerve superior oblique
IV (trochlear)
42
Tunics of eyeball
Fibrous
Vascular
Sensory
43
Humors
Fluids that fill inside of eyeball
Give shape
44
Lens divides eye into
Two chambers
Anterior posterior chambers
45
Fibrous layer
Outside layer
Sclera
46
Vascular layer
Middle layer
47
Sensory layer
Inside layer
Photoreceptors and pigment layer
48
Outermost fibrous layer of eye
Sclera
49
Middle layer or eye
Choroid
Vascular
50
Retina
Innermost layer
Sensory
rods
Cones
Photoreceptors
51
Focused light directed to
Fovea Centralis
52
Fovea Centralis
Higher concentration of photoreceptors
More cones
Higher visual acuity
53
Parts of fibrous layer
Sclera+ cornea
54
Cornea
Transparent,
Central anterior portion
Lets light pass through
55
What repairs itself easily?
Cornea
56
Only human tissue that can be transplanted w/o fear of rejection
Cornea (lack of blood vessels)
57
Choroid
Blood rich
Nutritive layer
Pigment that prevents light from scattering
58
Choroid modified anteriorly into two smooth muscle structures known as
Ciliary body
Iris
59
Ciliary body
Attached to lens by suspensory ligament called ciliary zonule
60
Iris
Regulates amount of light entering eye
61
Function of pigmented layer of iris
Gives eye color
62
Pupil
Rounded opening in iris
63
Point where light enters into eye from cornea
Pupil
64
Light passes from cornea to
Lens and after to retina
65
Layers of retina
Pigmented layer
Inner Neural layer
66
Inner neural layer
Has rods and cones
67
Outer pigmented layer
Absorbs light and prevents it from scattering
68
Sensory layer
Signals pass from photoreceptors via a
Two neuron chain
69
Two neuron chain made of
Bipolar cells
Ganglion cells
70
Signals leave retina towards brain through
Optic nerve
71
Optic disc
Blind spot
Optic nerve leaves eyeball
72
Cannot see images focused on
Optic disc
73
Phototransduction
Specialized outer segment of photoreceptors
Capture light and converts into electrical signals
74
Photoreceptors (rods)
Pick up photons peripheral vision
75
Cones
visualize visible light. Different colors
76
Axons of ganglion cells make
optic nerve
77
Three major types of neurons that make retina
Rods (photoreceptors)
Cones (visible light)
Bipolar cells
78
Central artery and vein of retina
Rich blood supply to and from eye
79
Rods found in
Edges of retina
80
What allows vision in dim light?
Rods
81
What allows peripheral vision
Rods
82
Perception is in grey tones
Rods
83
Where are cones densest ?
Center of retina
84
Fovea Centralis location
Lateral to blind spot
85
Area of retina w/ only cones
Fovea Centralis
86
Highest visual acuity
Fovea Centralis
87
No ______ are at the optic disc or blind spot
Photoreceptor cells
88
Allow for detailed color vision
Cones
89
Point where optic nerve enters and exits eye
Optic disc
90
Photopsin 1
Red pigments
91
Photopsin 2
Green
92
Photopsin 3
Blue or violet pigments
93
Lens
Flexible,
Biconvex crystal-like structure
94
Lens held in place by
Held by suspensory ligament attached to ciliary body
95
Lens sits posterior to
Iris
Cornea
Pupil
96
Lens flexibility helps it
Focus and accommodate light passing through lens
97
Explain how focus happens
Ciliary muscle pulls on lens to let focus
98
Ciliary zonule
Suspensory ligaments
99
Aqueous segment
Anterior segment of lens
Has aqueous humor
100
Vitreous segment
Posterior segment of lens
Gel like vitreous humor
101
Aqueous humor
Watery fluid between lens and cornea, sim. to plasma
102
What helps maintain intraocular pressure?
Aqueous humor
103
Function of aqueous humor
Maintain intraocular pressure
Nutrients for lens and cornea
104
How is aqueous humor reabsorbed?
Scleral venous sinus
Canal of schlemm
105
Vitreous humor function
Prevents eye from collapsing
Maintain intraocular pressure
106
Ophthalmoscope
Illuminates inside of eyeball and fundus
107
Fundus
Posterior wall of eye
108
What can ophthalmoscopes detect?
Diabetes, arteriosclerosis,
Degeneration of optic nerve and retina
109
Dark area of eye
Macula
Houses fovea centralis
110
For optimal vision, light must be
Focused to a point on the retina for optimal vision (fovea centralis)
111
What bends or refracts light?
Cornea
Aqueous humor
Lens
Vitreous humor
112
Eye is set for _____ vision over 20 ft away
Distant
113
Accomodation
Lens must change shape to focus on objects less than 20 ft away
114
When looking at light from distant source lens is
Flatter
115
When looking at light from closer source lens is
More curved
116
Image formed on retina is a
Real image
117
Real images are:
Reversed from left to right
Upside down
Smaller than the object
118
Visual fields and visual pathways to the brain
Optic nerve
Optic chiasma
Optic tracts
Optic radiation
119
Optic nerve
Bundle of axons that exit back of eye carrying impulses through retina
120
Optic chiasma
Location where optic nerves cross
Fibers from the medial side of each eye cross over to the opposite side of the brain
121
Signals passed through ____ to the optic nerve
Transduction
122
Optic tracts synapse with
Synapse w/ neurons in thalamus
123
Optic tracts contain
Fibers from lateral side of eye on same lateral side
Fibers from medial side come from the opposite eye
124
Optic radiation
Axons from thalamus run to the occipital lobe
125
Optic radiation synapse with
Cortical cells and vision interpretation (sight) happens
126
Summary of the pathway from retina to point of visual interpretation
1. Optic nerve
2. Optic chiasma
3. Optic tract
4. Thalamus
5. Optic radiation
6. Visual cortex in occipital lobe of brain
127
Left visual field ends up on
Right cortex and vice versa
128
Binocular vision results and provides
Depth perception (3D vision)
129
Each eye sees a
Slightly different view
130
Field of view _____ for each eye
Overlaps
131
Emmetropia
Normal eye vision
Eye focuses images correctly on retina
132
Myopia
Nearsightedness
133
Myopia results from
Too long eyeball
134
How do distant objects appear with myopia
Blurry
135
What happens in myopia
Light from objects fails to reach retina
Focused in front of it
136
Hyperopia
Farsightedness
137
In hyperopia near objects are
Blurry, distant objects are clear
138
Describe focus in hyperopia
Distant objects focused behind retina
139
Hyperopia results from
Too short eyeball
or
"Lazy lens"
140
Astigmatism
Images are blurry
Unequal curvature of cornea or lens
141
Astigmatism results from
Light focusing as lines not points on the retina because of unequal curvatures of the cornea or lens
142
Concave lens correct which eye
Myopic
Move focus point further back
143
Convex lens move focal point ______ fix ______ eye
Forward
Hyperopic
144
Cylindrically ground lenses fix
Astigmatism
145
Convergence
Reflexive movement of the eyes medially when we focus on a close object
146
Photopupillary reflex
Bright light causes pupils to constrict
147
Accomodation pupillary reflex
Viewing close objects causes pupils to constrict
148
Ear houses 2 senses
Hearing
Equilibrium
149
Receptors in ear are called
Mechanoreceptors
150
Three areas of ear
External
Middle
Internal
151
Auricle aka
Pinna
152
Auricle or pinna is
Outer ear
Visible portion
Directs sound waves to canal
153
Parts of outer ear
Pinna (auricle)
External acoustic meatus
154
External acoustic meatus
Auditory canal
Narrow chamber in temporal bone
Lined with ceruminous glands
155
Cerumen
Earwax
Traps foreign objects
Repels insects
156
External acoustic meatus ends at
Tympanic membrane
157
Tympanic membrane is aka
Eardrum
158
Middle ear cavity
Tympanic cavity
159
Air filled, mucosa lined cavity within temporal bone
Tympanic cavity
160
Tympanic cavity is only involved in
Sense of hearing
161
Tympanic cavity location
Between tympanic membrane (laterally)
Medially by bony wall w/ two openings
Oval window
Round window
162
Pharyngotympanic tube
links middle ear cavity with throat
Equalizes pressure in middle ear cavity so eardrum can vibrate
163
Ossicles (bones) inside tympanic cavity
Malleus (hammer)
Incus (anvil)
Stapes (stirrup)
164
Function of ossicles in middle ear
Transmit and amplify vibrations from tympanic membranes to fluids in the inner ear
165
Describe how vibrations travel in middle ear
Hammer>anvil>stirrup> oval window of inner ear
166
Hammer attached to
Tympanic membrane
167
Inner ear includes sense organs for
Hearing and balance
168
Bony labyrinth consists of
Cochlea
Vestibule
Semicircular canals
169
Bony labyrinth is filled with
Perilymph
170
Membranous labyrinth is suspended in _______
Perilymph
171
Membranous labyrinth contains
Endolymph
172
Parts of inner ear
Bony labyrinth
173
Spiral organ of corti located within
Cochlear duct
174
Spiral organ of corti
Has receptors=hair cells on basilar membrane
Gel, like tectorial membrane that can bend hair cells
175
Cochlear nerve attached to the hair cells transmits nerve impulses to
Auditory cortex on temporal lobe
176
Pathway of vibrations from sound waves
1. Auricle (pinna)
2. External acoustic meatus
3. Tympanic membrane
4. Ossicles amplify sounds
5. Oval window
6. Basilar membrane in spiral organ of corti
7. Hair cells of tectorial membrane bent when basilar membrane moves against it
8. Action potential starts in cochlear nerve (cranial nerve 8)
9. Impulse travels to auditory cortex in temporal lobe
177
High pitched sounds disturb
Short, stiff fibers of basilar membrane
Receptor cells close to oval window are stimulated
178
Low pitched sounds disturb
Long, floppy fibers of basilar membrane
-specific hair cells further along cochlea are affected
179
Vestibular apparatus
Equilibrium receptors of inner ear
180
Vestibular apparatus has two functional parts
Static and dynamic equilibrium
181
Maculae
Receptor in vestibule
Report on position of head
Help keep head erect
182
How do maculae send information
Via vestibular nerve (part of cranial nerve 8) to cerebellum of brain
183
Anatomy of maculae
Hair cells embedded in otolithic membrane
Otoliths float in gel around hair cells
184
What causes otoliths to roll and bend hair cells
Movements
185
Otoliths
Tiny stones
186
Oto-
Ear
187
-Lith
Stone
188
Crista ampullaris
Responds to angular or rotational movements of head
189
Crista ampullaris location
In ampulla (expanded portion) of each semicircular canal
190
Tuft of hair cells in Crista ampullaris covered w/
Cupula (gelatinous cap)
191
If the head moves, the cupula,
Drags against the endolymph
192
If cupula drags against endolymph,
Hair cells are stimulated,
Impulse travels the vestibular nerve to the cerebellum
193
Deafness
Any degree of hearing loss
194
Conduction deafness
Sound vibrations hindered through external and middle ear
195
Sensorineural deafness
Damage to nervous system structures involved in hearing
196
Menieres syndrome
Affects inner ear
Progressive deafness
Often vertigo
197
Chemical senses
Smell
Taste
198
Chemoreceptors
Stimulated by chemicals
199
Taste has _ types of receptors
5
200
Smell can differentiate a
Wider range of chemicals
201
Taste and smell compliment each other; respond to
Many of same stimuli
202
Olfactory receptors are in
Roof of nasal cavity
203
Olfactory receptor cells are a type of
Neuron
204
Olfactory hairs
Long cilia on olfactory receptor cells
Detect chemicals
205
Olfactory receptors can only detect chemicals that are
Dissolved in mucus
206
Impulses are transmitted via the olfactory
Filaments to cranial nerve I (olfactory nerve)
207
Smells are interpreted in
The olfactory cortex
208
Taste buds house
Receptor organs
209
Locations of taste buds
Most of tongue
Soft palate
Superior part of pharynx
Cheeks
210
Tongue covered w/ projections called
Papillae
211
Fungiform papillae
Bumps on tongue
Button like
212
Foliate papillae
Ribbed lines on side of tongue
213
Vallate papillae
Posterior aspect of tongue
Straight line
Concentric nodules
Highest # of taste buds
Largest of taste buds
214
Gustatory cells
Taste receptors
Have gustatory hairs
215
Gustatory hairs
Long microvilli
Protrude through taste pore
216
How are gustatory hairs stimulated
Chemicals dissolved in saliva
217
Gustatory cells synapse with
Sensory nerve fibers and through basal cells into connective tissue layer
218
Impulses carried to gustatory complex by several cranial nerves because
Taste buds found in different areas
219
Taste buds are frequently replaced by
Basal cells
220
Nerves that carry gustatory impulses
Facial nerve (7)
Glossopharyngeal nerve (9)
Vagus nerve (cranial nerve 10)
221
Neuronal cells capable of regeneration
Taste buds
Olfactory cells
222
Sweet receptors
Most on top of tongue
Respond to sugars, saccharine,
Some aminoacids
223
Sour receptors respond to
H+ ions or acids
Sides
224
Bitter receptors respond to
Alkaloids
225
Salty receptors respond to
Metal ions
226
Umami receptors respond to
Amino acid glutamate
Or beefy taste of meat
