Sense Organs Flashcards
(239 cards)
1
Q
What two subcategories fall under conscious control ?
A
Special senses and somatic senses
2
Q
What are the special senses(conscious) ?
A
vision, hearing, taste, smell, and equilibrium?
3
Q
What are the somatic senses(conscious)?
A
Touch/pressure, temperature, pain, and proprioception.
4
Q
What two subcategories fall under unconscious control?
A
Somatic stimuli and visceral stimuli
5
Q
What is somatic stimuli(unconscious) ?
A
muscle length and tension
6
Q
What are the visceral stimuli(unconscious)?
A
blood pressure, ph/oxygen content in blood , ph of CSF, lung inflation, osmolarity of body fluids, and blood glucose.
7
Q
Describe a simple receptor
A
neurons with free nerve endings
8
Q
Describe a complex neural receptor
A
nerve ending enclosed in connective tissue capsules
9
Q
Describe special senses receptor
A
cells that release NT onto sensory neurons initiating an action potential
10
Q
What are the three kinds of unencapsulated nerve endings? What do they do?
A
free nerve endings(warm cold, pain receptors) , tactile discs(associated with base if epidermis) , and hair receptors(monitor movement of hairs).
11
Q
What are the four encapsulated nerve endings?
A
ruffini corpuscles, tactile (meissner) corpuscles ,krause end bulb, and lamellated (pacinian) corpuscles
12
Q
True or false unencapsulated nerve endings are found as receptors for the general sense. Their Dendrites are not wrapped in connective tissue
A
True
13
Q
What are ruffini corpuscles for ?
A
heavy touch, pressure, joint movements &; skin stretching
14
Q
what are tactile (meissner) corpuscles for?
A
light touch &texture
15
Q
what are krause end bulbs for?
A
tactile corpuscles in mucous membranes
16
Q
what are lamellated (pacinian) corpuscles for?
A
deep pressure, stretch, tickle & vibration
17
Q
True or false the Dendrites on encapsulated nerve endings are wrapped by glial cells or connective tissue
A
True
18
Q
What are the 4 characteristics of receptors?
A
modality(type of stimulus), location of stimulus, intensity (frequency of firing), and duration.
19
Q
What are phasic receptors
A
give burst of activity &quickly adapt
20
Q
What are tonic receptors
A
adapt slowly & generate impulses continually
21
Q
True or false all receptors are transducers
A
True, they convert one form of energy to another.
22
Q
What are the 5 modality receptors?
A
chemoreceptors, thermoreceptors, nociceptors(pain), mechanoreceptors and photoreceptor
23
Q
What are the 2 distribution receptors ? what do they do?
A
general (somesthetic) sense(widely distributed), special senses (limited to head)
24
Q
What do exteroreceptors pick up ?
A
touch, pressure, pain, temperature, special senses
25
What are merklel's discs?
free nerve with disc shaped ending deep in the dermis and are for light touch
26
What are meissner's corpuscles ? Where are they found?
dermal papillae of hairless skin(lips,nipples, and finger tips) They respond to light pressure and discriminate touch .
27
What are krause's end bulbs? Where are they found?
in the mucosa EX. mouth, conjuctiva, hairless skin near body openings. They detect the same as the meissner's.
28
What are pacinian corpuscles? where are they found?
in hypothermis, respond to deep pressure and stretching . Respond only when pressure is first applied.
29
what are ruffini's corpuscles? where are they found?
Found in deep dermis , hypodermis, and joint capsules. They detect the same as the pacinian
30
What are examples of interoreceptors and what do they detect?
free nerve endings and pacinian corpuscles , they detect pain ,discomfort, stretching tissue, and temperature.
31
When responding to internal stimuli in muscles and joints what 3 groups monitor the degree of stretch?
muscle spindles, golgi tendon organs, receptors in joint capsules.
32
What are 1st order neurons?
afferent neurons that are large, fast, and myelinated
33
What are 2nd order neurons ?
decussate, and synapse at the thalamus.
34
What are 3rd order neurons?
go from the thalamus to the post central gyrus (somesthetic cortex)
35
Describe a heat and cold neuron and where they decussates
small, slow, unmyleinated, decussate at entrance of spinal cord
36
Define adaptation
When the frequency of receptor firing declines after prolonged stimulus exposure.
37
Define Tonic receptors and give an example of one
adapt slowly and generate nerve impulses more steadily. proprioceptors are among the slowest to adapt cause they have to always take into account body position.
38
Define phasic receptors and give an example of one
generate a bunch of action potential when 1st stimulate, then quickly adapt, and sharply reduce, or halt signal transmission even if stimulus continues. smell receptors adapt quickly.
39
Define receptor field
The region within a tactile stimulus evokes a sensory response in the cell or its axon.
40
How can you measure receptor fields ?
two pint discrimination (poke person with compass and ask if it was two poke or one)
41
True or false temperature sensitivity is uniformly distributed
False it is NOT evenly distributed
42
True or false there are more cold receptors than warm receptors
True
43
True or false temperature receptors can adapt
True
44
Were does somatic pain arise ?
skin, muscles, and joints
45
Injured tissues release release what chemicals that stimulate pain fibers?
bradykinin, histamine, protaglandin
46
What is the projection pathway for neurons?
1st order cell bodies on dorsal root release chemicals (glutamate or substance P)
2nd order decussate up spinothalamic tract to thalamus
3rd order reaches post central gyrus
47
What is referred pain?
misinterpreted pain . Brain assumes pain is coming from the skin not the organ
48
What three parts of the spinal cord (transverse section) are part of the somatosensory pathways?
Posterior, anterolateral coulmmns on the spinal cord
49
The axon that ascend within the fasciculus gracilis and fasciculus cuneatus of posterior column relay information to the thalamus via what ? (somatic pathway in spinal cord) and what kind of information does it carry ?
medial lemniscus .Carries fine touch, pressure and proprioceptive sensations
50
Describe the anterolateral pathway . What kind of information does it carry ?
axons decussate in spinal cord and ascend within anterior and lateral spinothalmic tracts and head toward ventral nuclei of the thalamus. carries poorly localized sensations of touch pressure, pain, and temperature.
51
true or false, intensity of pain is affected by the state of mind
True
52
Where are pain receptor sites found in the spinal cord ?
Pain signals are found in the central gray of midbrain and the dorsal horn of the spinal cord
53
spinal ______ stops pain signals at dorsal horn
Gating
54
What are the three primary pain signals
primary somesthetic cortex, sometsthetic association area, hypothalamus and limbic system, and reticular formation .
55
what does the spinocerebellar pathway do ?
includes posterior and anterior spinocerecellar tracts and carries sensation to the cerebellum concerning position of muscles, tendons, and joints.
56
Gustation
sensation of taste resulting from the action of chemicals on the taste buds
57
how many kinds of lingual papillae are there ? What are their names.
filiform, foliate, fungiform, and circumvallate
58
What lingual papillae is the most abundant? What is its function? Do they have taste buds?
Filifiorm papillae look like tiny spikes without taste buds, appreciates texture of food.
59
What lingual papillae mostly degenerate by age 3 ? Do they have taste buds?
Foliate papillae , weakly developed in humans, forms parallel ridges in back of tongue. No taste buds
60
What lingual papillae is at the tip and sides of tongue?
fungiform papilae , theyre mushroom shaped
61
What lingual papillae has only 7-12 on your tongue but contains 250 taste buds each?
Circumvallate papillae. They are arranged ina v at the rear of the tongue
62
Describe hairy tongue and what causes it .
Tobacco staining in the filiform papillae from smoking or antibiotics. Only treatment is to stop smoking and brush tongue.
63
Describe geographic tongue and what causes it.
Loss of filiform papilae leaving atrophic tongue . Caused by life stress.
64
Describe furrowed tongue and what causes it
furrows get more prominant with old age and in the furrows bacteria can accumulate causing malodor . There is no treatment aside from brushing tongue.
65
Describe smooth tongue and what causes it
smooth, caused by vitamin B deficiency and anemia
66
What are the three kinds of cells in the taste bud structure ?
taste , supporting, and basal cells.
67
True or false taste buds synapse with sensory nerve fibers at their base
True
68
True or false taste buds are neurons that synapse with sensory neurons .
False , taste buds are epithelial cells.
69
What are taste hairs?
microvilli that serve as receptor surface for taste molecules in taste cells
70
what is a taste pore ?
a pit on the epithelial surface of the tongue
71
What is the purpose of supporting cells?
contain microvilli and secreare substances into lumen of taste bud
72
What is the purpose of basal cells?
replace degenerated taste cells every 7-10 days
73
To be tasted molecules must _____
dissolve in saliva
74
What re the 5 primary sensations?
salty, sweet, sour, bitter, and umami(taste of an amino acid )
75
Sweet tastes concentrated on what part of the tongue?
Tip of the tongue
76
salty tastes & sour are concentrated on what part of the tongue.
lateral margins of tongue
77
Bitter tastes are concentrated on what part of the tongue?
rear part
78
True or False sugars and umamI flavors bind to receptors and activate 2nd messenger systems
true
79
True or false sodium and acids penetrate cells and depolarize them
true
80
The facial nerve(VII)controls for what part of the tongue ?
anterior 2/3 of the tongue
81
The glossopharyngeal (IX) controls what part of the tongue?
posterior 1/3
82
What part of the mouth does the vagus nerve (X) control?
palate, pharynx, and epiglottis
83
Where do all the fibers project to?
solitary nucleus in the medulla
84
Where do CELLS project to for autonomic reflexes ?
thalamus and amygdala
85
Were do CELLS project to for sense of taste ?
thalamus and post central gyrus
86
what triggers the production of a second messenger in smell?
volatile molecules binding to an olfactory receptor
87
how are receptors able to quickly adapt in the olfactory bulbs?
Synaptic inhibition
88
where do the axons of the bulb cells of the olfactory tract lead to? what is it responsible for?
leads to temporal lobe, amygdala, & hypothalamus. They are responsible for cough, salivate, sneeze or vomit in response to odors. emotional responses to odors
89
For what does the cerebral cortex sends feedback to bulb cells
changing quality &; significance of odors when hungry
90
what are the olfactory projection pathways ?
Hippo campus (conscious perception), Amygdala (emotional response), Reticular formation (visceral response), olfactory cortex of temp. lobe (conscious perception )
91
True or false Receptor cells for olfaction form olfactory mucosa. What does the mucosa cover ?
True , superior concha and nasal septum
92
What are olfactory cilia called?What are they for?
olfactory hairs . The cilia are binding sites for odors (volatile molecules)
93
True or false Olfactory receptor cells are neurons with a modified dendrite
True
94
What kind of neurons are olfactory hairs? (polar)
They are bipolar neurons that transduce chemical sensations into neural signals
95
What nerves are the only kind to be directly exposed to the external environment?
olfactory hairs
96
What are the other cell types present in olfactory epithelium(in mucosa ).
supporting cell, basal cell, olfactory cell
97
What is the purpose for the supporting cell?
provides physical and nutritive support, its ciliated
98
What is the purpose for the basal cell?
glial element (glue) they also differentiate into new olfactory cells every 60 days.
99
Granule cells receive signals from the cortex and are ________ to the mitral cells (causing adaptation)
Inhibitory
100
The axons from what cells form bundles called the olfactory tract
the mitral and tuft cells
101
What is sound?
Any audible vibration of molecules
102
molecules in the air connect with what in the ear making it vibrate?
Tympanic membrane
103
True or false sounds grater than 90 decibles (dB) can cause damage
true
104
what gives us sense of pitch?
frequency of the ear vibrating
105
What is "loudness" ?
perception of sound intensity
106
How are waves categorized?
frequency and intensity
107
What is frequency?
greater the frequency the higher the pitch, measured in hertz (cycles per sec.)
108
What is intensity ?
directly related to amplitude of sound waves, measured in decibles.
109
What part of the ear directs vibrations down the auditor canal ?
Auricle/pinna (your whole outer ear)
110
What are the three regions of the ear?
Outer, middle, and inner.
111
What is the purpose of the outer and middle ear?
transmission of sound into inner ear.
112
What is the purpose of the inner ear?
converts sound into fluid motion and then to electrical impulses(action potential)
113
Why is the tympanic cavity thats filled with air connected to the nasopharynx?
to equalize air pressure on both sides of eardrums . Done by yawning and swallowing.
114
True or false the stapes is attached to the eardrum ?
True
115
True or false the incus and stapes is attached to the oval window
True
116
How is the cochlea protected ?
Tensor tympani pulls eardrum inward to reduce mobility of ear bones .
117
What is the smallest muscle in the skeletal body?
stapedius , connects to stapes and reduces its action . Contracts before speaking and chewing.
118
What CN innervates the stapedius muscle?
CN VII facial nerve
119
What CN innervates the Tensor Tympani muscle?
CN V Trigeminal , madndibular branch(V3)
120
What is a Myringotomy tube for?
Equalization of air behind the eardrum so it doesn't build up with fluid and cause hearing disorders.
121
How is sound in the inner ear produced ?
vibrations of ossicles and basilar membrane under hair cells
122
What portion of the cochlea is responsible for the ascending fluid (perilymph)?
scala vestibuli
123
What portion of the cochlea is responsible for the descending fluid (perilymph)?
scala tympani
124
what structure is found inside the cochlear duct?
Organ of cordi
125
What is the name of the fluid inside the cochlear duct (cochlear duct is in between the scalas) ?
endolymph
126
How are stereocilia depolarized ?
Movement of the tectorial membrane moves the embedded cilia tips causing an influx of potassium which depolarizes and releases NT. stimulating sensory dendrites
127
What NT is released when stereocillia are depolarized ?
glutamate
128
What lobe is the site of conscious perception ?
Temporal
129
Define equilibrium
control of coordination and balance
130
Define static equilibrium
perception of head orientation perceived by macula
131
Define dynamic equilibrium
perception of motion or acceleration perceived by macula and crista
132
What does the vestibular apparatus maintain?
maintains body at equilibrium and stabilize the eyes relative to the environment .
133
What two structures does the vestibular apparatus have ?
otolithic organs(static) and semicircular canals(dynamic)
134
What structures does the macula consist of?
sensory hair cells and supporting cells (sustentaculare cells ) for keen vision and contains fovea
135
Define Utricle
irregular oblong membraneous sac on the medial wall of vestibule , most sensitive to horizontal acceleration.
136
What is the otolithic membrane and where does it sit?
gelatinous membrane, produced by sustenticular cells, that sits on top of sensory cells.
137
What are otoliths?
Crystals of calcium carbonate that are sensitive to horizontal movements
138
Define saccule
flattened membranous sac located in the medial wall of the bony vestibule. Most sensitive to vertical movement
139
What direction is the saccular macula most sensitive to?
Vertical, Up, down, forward, and back
140
Describe Crista Ampullaris
Hair cells buried in a mound of gelatinous membrane
141
True or Flase ?Hair cells of macula sacculi, macula utriculi & semicircular ducts synapse on vestibular nerve
True
142
What is vision (sight)?
Perception of light emitted or reflected from objects in the environment.
143
What do tarsal glands secrete?
Oil that reduces tear evaporation (white krusties in the morning)
144
True or False the conjunctiva is highly vascular
True
145
What are the three layers of the tunic (eyeball)?
Tunica Fibrosa, Tunica Vasculosa, Tunica Interna
146
What consists of the Tunica Fibrosa?
Scalera and cornea (avascular)
147
What consists of the Tunica Vasculosa?
Choroid, ciliary body and iris (Vascular)
148
What consists of the Tunica Interna?
Retina
149
what is aqueous humor?
serious fluid produced by ciliary body that flows from post. chamber through pupil to ant. chamber
150
what reabsorbs left over aqueous humor ?
Canal of schlemm (Sclera Venous sinus)
151
What is deep to the sclera and is highly vascular?
Choriod (vascular tunic)
152
The choroid continues to the anterior portion of the vascular tunic and becomes what structure?
Ciliary body
153
What secrets aqueous humor?
Ciliary processes in the ciliary body
154
What part of the ciliary body are the suspensory ligaments?
Zonular fibers
155
What is the function of the ciliary muscle?
Contracts and relaxes to alter the shape of the lens to adapt for near or far vision
156
What is the function of the iris ?
Regulates the amount of light entering the pupil (suspended between the cornea and lens)
157
Describe optic disc
Site where the optic nerve and retinal artery and vein enter and exit the eye (blind spot)
158
What does the neural apparatus include?
The retina and optic nerve
159
What is the function of melanin in the retina ?
Absorbs stray light and prevents reflection allowing for sharp images
160
What are the three layers of retinal neurons from superficial to deep?
Photoreceptor layer, Biopolar cell layer, and Ganglion cell layer
161
What are the two types of photoreceptors ?
Rods and cones
162
Explain rods
low light threshold, good for dim light, NO COLOR, and shades of gray
163
Explain cones
higher light threshold, color vision, difficult seeing in dim light
164
True or False? The loss of cones causes visual legal blindness
True
165
True or False? There are more rods than cones
True, 120 million rods to 6 million cones
166
Define Macula Lutea
Exact center of posterior retina
167
Define Central Fovea
Small depression in center of Macula Lutea that contain only cones.
168
True or False? the Macula Lutea contains ONLY cones
True
169
Where is the lens located?
Behind the pupil and iris
170
What divides the internal eye into Anterior and Posterior cavities?
The lens
171
What is the purpose of aqueous humor and where is it found?
Nourishes the lens, provides intraocular pressure and is found in the anterior cavity of the interior eye
172
What maintains the shape of the eyeball and prevents it from collapsing?
Intraocular pressure
173
What is the function of vitreous body ?
A jelly-like substance that contributes to intraocular pressure that holds the retina flush against the choroid
174
True or False? Vitreous body does not undergo constant replacement
True
175
Define hyaloid canal
narrow channel that was occupied by the hyaloid artery in the fetus
176
What type of cells remove debris from the vitreous body?
Phagocytic cells
177
Image formation involves what four things?
Refraction, accommodation, light control, and convergence
178
True or False? The cornea refracts more light than the lens
True
179
True or False? Lens shifts focus between near and distinct objects
True
180
What kind of vision is Emmetropia?
Normal distant vision
181
what is Myopia?
Nearsightedness, focus power to strong, or eyeball to long,
182
what is hyperopia ?
Farsightedeness, focus power to weak, or eyeball to short.
183
Define Astigmatism
Caused by an unevenly shaped eyeball, cornea, or lens
184
Define Presbyopia
At an old age the lens loses elasticity and its ability to accommodate
185
Define Cataracts
clouding of the normally clear lens of the eye
186
Define convergence
Both eyes looking at the same object
187
Describe the Photopupillary reflex
Both pupils constrict when one eye is illuminated (parasympathetic reflex)
188
What does the constriction of the pupil prevent ?
doesn't allow peripheral light rays in and reduces aberrations(blurry edges)
189
How is the lens accommodated ?
Contraction of ciliary muscle relax the suspensory ligaments and allows the lens to relax into a convex shape allowing light to refract strongly onto the retina as needed.
190
What kind of lens do you need to correct hypertropia?
convex lenses
191
What kind of lens do you need to correct Myopia ?
concave lenses
192
Define photo-pigments, where are they found?
integral proteins in the plasma membrane of the outer segment
193
Define rhodopsin
photopigment in rods (outer segment)
194
Define photopsin or iodopsin
there are three types one for each type of cone
195
What two parts do all photopigments contain ?
opsin, and retinal
196
What does opsin do?
one for each color and one for rhodopsin , 4 all together. They absorb different wavelengths (different colors)
197
What wavelength is perceived as Red by opsin?
long wavelengths
198
What wavelength is perceived as Green by opsin?
middle wavelengths
199
What wavelength is perceived as Blue by opsin?
short wavelengths
200
What does retinal in a photopigment do? Why do they store vitamin A?
The part of the photopigment that absorbs light. Vitamin A is stored in photopigmented cells for regeneration in rods
201
Why do you feel pain when you turn on a bright light in the middle of the night ?
Your pupil was dilated at the time you were exposed to the bright light and over stimulated your retina.
202
In dark adaptation why cant you see well at first when the lights are turned off?
The rhodopsin was bleached (it was seeing white and when the lights turned off they were resting meaning you only saw pitch black until they recovered) but returns to it maximally possible sensitivity in the dark in 20-30 min.
203
Upon illumination what happens to the CNG channels?
The CNG channels close and the photoreceptor hyperpolarizes
204
In the dark what happens to the CNG channels?
The CNG(in the plasma membrane) channels are kept open by cGMP and the cell depolarizes.
205
What part of the photopigment is activated with bleaching.
Opsin
206
List the chain of events that causes the CNG channels to close when light enters the eye
The light enters and activates rhodponsin wich activates transducin, which activates phosphodiesterase which breaks down cGMP (keeps the gate open) into GMP which no longer can keep the gate open so therefore closes in the day
207
Bipolar cells synapse with what other 3 cells
rods, cones, and ganglion cells
208
What are the largest neurons of the retina?
Ganglion cells
209
What are horizontal and amacrine cells responsible for?
enhancing perception contrast, edges of objects, and changes in light intensity.
210
Describe the shape of rhodopsin when it is cis-retinal
the shape is bent
211
Describe the shape of rhodopsin when it is transretinal?
it is straight , becomes straight when bleached
212
What is the shape of rhodopsin when it is bleached?
It is straight, trans-retinal
213
How does a patient fail the webers test?
they fail to hear the tuning fork equally in both ears
214
If a person cant hear the tuning fork well in one ear meaning they have failed the webers test where can you place the tuning fork to where they can hear it ?
You can place the tuning fork on the mastoid process. If they do hear it when placed on the bone easier then when placed on the ear , they still failed the test, and something is wrong.
215
What do rods produce in the dark that causes no signal in the optic nerve?
a steady ion flow that causes a IPSP
216
What causes the dark current to cease ? (in the rods)
When the light hits the rods the dark current ceases and no longer inhibits EPSP.
217
Photorecpetors are derived from stem cells that produced what neuroglia?
ependymal cells
218
Bipolar are __ order neurons and Ganglion are __order neurons.
Bipolar 1st ganglion 2nd . Everything converges down to the ganglion neurons that make up the optic nerve.
219
What is the ratio of rods to bipolar cells? How does this ratio affect your vision?
600 rods to one bipolar cell. The convergence of all the rods onto one bipolar cells creates mixed messaged due to spatial summation resulting in low resolution.
220
Photopic is to ____ vision and Scotopic is to____ night vision.
Photopic is to day vision, Scotopic is to night vision.
221
True or false there is are rod cells in the fovea
False
222
True of false each foveal cone cell has its own private line to the brain
True, no neural convergence.
223
True or false foveal cones are less sensitive to light intensity.
True
224
Do nocturnal vertebrates have cones ?
No they only have rods
225
What is the perception of color?
perception of color is based off of a mixture of nerve signals.
226
True or false is color blindness hereditary?
Yes, males carry the gene and in general 8% has the recessive gene .
227
Where doe conscious visual sensation occur?
Visual cortex
228
Where are the 3rd order neurons for the eyes?
lateral geniculate nucleus of the thalamus
229
what does the association areas in parietal and temporal lobes process what types of visual data?
object location, motion, color, shape, boundaries, and store visual memories (recognize printed words).
230
Macular degeneration is most common in who?
old people and is the leading cause of blindness
231
What causes Macular degeneration?
degeneration of pigmented epithelium leading to leakage of fluid behind macula and fovea causing white spots.
232
Why cant ppl with macular degeneration read or see fine print?
The cones of the fovea die causing central visual loss.
233
what causes glaucoma
Anterior chamber of the eye cannot exchange fluid properly by the normal aqueous outflow. Pressure compromises the blood vessels of the optic nerve and eventually the axons of the ganglion cells so that these vital cells die.
234
What kind of treatment is essential for glaucoma ?
release of intraocular pressure
235
Describe Diabetic Retinopathy
side affect of diabetes that can cause blindness by blood vessels multiplying in uncontrollable ways.
236
What is the most common treatment of Diabetic Retinopathy ?
Laser treatment for stopping blood vessel proliferation and leakage of fluid into the retina
237
True or false Retinitis Pigmentosa is hereditary .
True
238
Why do patients with Retinitis Pigmentosa have tunnel vision?
The rods of the peripheral retina degenerate , causing night blindness, only the cones in the fovea are left resulting in the tunnel vision
239
What causes the rods to die in a patient with Retinitis Pigmentosa?
Thinned blood vessels at the optic nerve head (less blood supply causing atrophy of rods)
