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Anatomy & physiology 102 > Sense Organs > Flashcards

Sense Organs Flashcards

1
Q

What two subcategories fall under conscious control ?

A

Special senses and somatic senses

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2
Q

What are the special senses(conscious) ?

A

vision, hearing, taste, smell, and equilibrium?

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3
Q

What are the somatic senses(conscious)?

A

Touch/pressure, temperature, pain, and proprioception.

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4
Q

What two subcategories fall under unconscious control?

A

Somatic stimuli and visceral stimuli

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5
Q

What is somatic stimuli(unconscious) ?

A

muscle length and tension

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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.

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7
Q

Describe a simple receptor

A

neurons with free nerve endings

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8
Q

Describe a complex neural receptor

A

nerve ending enclosed in connective tissue capsules

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9
Q

Describe special senses receptor

A

cells that release NT onto sensory neurons initiating an action potential

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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).

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11
Q

What are the four encapsulated nerve endings?

A

ruffini corpuscles, tactile (meissner) corpuscles ,krause end bulb, and lamellated (pacinian) corpuscles

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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

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13
Q

What are ruffini corpuscles for ?

A

heavy touch, pressure, joint movements &; skin stretching

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14
Q

what are tactile (meissner) corpuscles for?

A

light touch &texture

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15
Q

what are krause end bulbs for?

A

tactile corpuscles in mucous membranes

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16
Q

what are lamellated (pacinian) corpuscles for?

A

deep pressure, stretch, tickle & vibration

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17
Q

True or false the Dendrites on encapsulated nerve endings are wrapped by glial cells or connective tissue

A

True

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18
Q

What are the 4 characteristics of receptors?

A

modality(type of stimulus), location of stimulus, intensity (frequency of firing), and duration.

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19
Q

What are phasic receptors

A

give burst of activity &quickly adapt

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20
Q

What are tonic receptors

A

adapt slowly & generate impulses continually

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21
Q

True or false all receptors are transducers

A

True, they convert one form of energy to another.

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22
Q

What are the 5 modality receptors?

A

chemoreceptors, thermoreceptors, nociceptors(pain), mechanoreceptors and photoreceptor

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23
Q

What are the 2 distribution receptors ? what do they do?

A

general (somesthetic) sense(widely distributed), special senses (limited to head)

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24
Q

What do exteroreceptors pick up ?

A

touch, pressure, pain, temperature, special senses

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25
Q

What are merklel’s discs?

A

free nerve with disc shaped ending deep in the dermis and are for light touch

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26
Q

What are meissner’s corpuscles ? Where are they found?

A

dermal papillae of hairless skin(lips,nipples, and finger tips) They respond to light pressure and discriminate touch .

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27
Q

What are krause’s end bulbs? Where are they found?

A

in the mucosa EX. mouth, conjuctiva, hairless skin near body openings. They detect the same as the meissner’s.

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28
Q

What are pacinian corpuscles? where are they found?

A

in hypothermis, respond to deep pressure and stretching . Respond only when pressure is first applied.

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29
Q

what are ruffini’s corpuscles? where are they found?

A

Found in deep dermis , hypodermis, and joint capsules. They detect the same as the pacinian

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30
Q

What are examples of interoreceptors and what do they detect?

A

free nerve endings and pacinian corpuscles , they detect pain ,discomfort, stretching tissue, and temperature.

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31
Q

When responding to internal stimuli in muscles and joints what 3 groups monitor the degree of stretch?

A

muscle spindles, golgi tendon organs, receptors in joint capsules.

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32
Q

What are 1st order neurons?

A

afferent neurons that are large, fast, and myelinated

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33
Q

What are 2nd order neurons ?

A

decussate, and synapse at the thalamus.

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34
Q

What are 3rd order neurons?

A

go from the thalamus to the post central gyrus (somesthetic cortex)

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35
Q

Describe a heat and cold neuron and where they decussates

A

small, slow, unmyleinated, decussate at entrance of spinal cord

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36
Q

Define adaptation

A

When the frequency of receptor firing declines after prolonged stimulus exposure.

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37
Q

Define Tonic receptors and give an example of one

A

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.

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38
Q

Define phasic receptors and give an example of one

A

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.

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39
Q

Define receptor field

A

The region within a tactile stimulus evokes a sensory response in the cell or its axon.

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40
Q

How can you measure receptor fields ?

A

two pint discrimination (poke person with compass and ask if it was two poke or one)

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41
Q

True or false temperature sensitivity is uniformly distributed

A

False it is NOT evenly distributed

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42
Q

True or false there are more cold receptors than warm receptors

A

True

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43
Q

True or false temperature receptors can adapt

A

True

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44
Q

Were does somatic pain arise ?

A

skin, muscles, and joints

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45
Q

Injured tissues release release what chemicals that stimulate pain fibers?

A

bradykinin, histamine, protaglandin

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46
Q

What is the projection pathway for neurons?

A

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

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47
Q

What is referred pain?

A

misinterpreted pain . Brain assumes pain is coming from the skin not the organ

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48
Q

What three parts of the spinal cord (transverse section) are part of the somatosensory pathways?

A

Posterior, anterolateral coulmmns on the spinal cord

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49
Q

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 ?

A

medial lemniscus .Carries fine touch, pressure and proprioceptive sensations

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50
Q

Describe the anterolateral pathway . What kind of information does it carry ?

A

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.

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51
Q

true or false, intensity of pain is affected by the state of mind

A

True

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52
Q

Where are pain receptor sites found in the spinal cord ?

A

Pain signals are found in the central gray of midbrain and the dorsal horn of the spinal cord

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53
Q

spinal ______ stops pain signals at dorsal horn

A

Gating

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54
Q

What are the three primary pain signals

A

primary somesthetic cortex, sometsthetic association area, hypothalamus and limbic system, and reticular formation .

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55
Q

what does the spinocerebellar pathway do ?

A

includes posterior and anterior spinocerecellar tracts and carries sensation to the cerebellum concerning position of muscles, tendons, and joints.

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56
Q

Gustation

A

sensation of taste resulting from the action of chemicals on the taste buds

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57
Q

how many kinds of lingual papillae are there ? What are their names.

A

filiform, foliate, fungiform, and circumvallate

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58
Q

What lingual papillae is the most abundant? What is its function? Do they have taste buds?

A

Filifiorm papillae look like tiny spikes without taste buds, appreciates texture of food.

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59
Q

What lingual papillae mostly degenerate by age 3 ? Do they have taste buds?

A

Foliate papillae , weakly developed in humans, forms parallel ridges in back of tongue. No taste buds

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60
Q

What lingual papillae is at the tip and sides of tongue?

A

fungiform papilae , theyre mushroom shaped

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61
Q

What lingual papillae has only 7-12 on your tongue but contains 250 taste buds each?

A

Circumvallate papillae. They are arranged ina v at the rear of the tongue

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62
Q

Describe hairy tongue and what causes it .

A

Tobacco staining in the filiform papillae from smoking or antibiotics. Only treatment is to stop smoking and brush tongue.

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63
Q

Describe geographic tongue and what causes it.

A

Loss of filiform papilae leaving atrophic tongue . Caused by life stress.

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64
Q

Describe furrowed tongue and what causes it

A

furrows get more prominant with old age and in the furrows bacteria can accumulate causing malodor . There is no treatment aside from brushing tongue.

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65
Q

Describe smooth tongue and what causes it

A

smooth, caused by vitamin B deficiency and anemia

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66
Q

What are the three kinds of cells in the taste bud structure ?

A

taste , supporting, and basal cells.

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67
Q

True or false taste buds synapse with sensory nerve fibers at their base

A

True

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68
Q

True or false taste buds are neurons that synapse with sensory neurons .

A

False , taste buds are epithelial cells.

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69
Q

What are taste hairs?

A

microvilli that serve as receptor surface for taste molecules in taste cells

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70
Q

what is a taste pore ?

A

a pit on the epithelial surface of the tongue

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71
Q

What is the purpose of supporting cells?

A

contain microvilli and secreare substances into lumen of taste bud

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72
Q

What is the purpose of basal cells?

A

replace degenerated taste cells every 7-10 days

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73
Q

To be tasted molecules must _____

A

dissolve in saliva

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74
Q

What re the 5 primary sensations?

A

salty, sweet, sour, bitter, and umami(taste of an amino acid )

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75
Q

Sweet tastes concentrated on what part of the tongue?

A

Tip of the tongue

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76
Q

salty tastes & sour are concentrated on what part of the tongue.

A

lateral margins of tongue

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77
Q

Bitter tastes are concentrated on what part of the tongue?

A

rear part

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78
Q

True or False sugars and umamI flavors bind to receptors and activate 2nd messenger systems

A

true

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79
Q

True or false sodium and acids penetrate cells and depolarize them

A

true

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80
Q

The facial nerve(VII)controls for what part of the tongue ?

A

anterior 2/3 of the tongue

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81
Q

The glossopharyngeal (IX) controls what part of the tongue?

A

posterior 1/3

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82
Q

What part of the mouth does the vagus nerve (X) control?

A

palate, pharynx, and epiglottis

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83
Q

Where do all the fibers project to?

A

solitary nucleus in the medulla

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84
Q

Where do CELLS project to for autonomic reflexes ?

A

thalamus and amygdala

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85
Q

Were do CELLS project to for sense of taste ?

A

thalamus and post central gyrus

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86
Q

what triggers the production of a second messenger in smell?

A

volatile molecules binding to an olfactory receptor

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87
Q

how are receptors able to quickly adapt in the olfactory bulbs?

A

Synaptic inhibition

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88
Q

where do the axons of the bulb cells of the olfactory tract lead to? what is it responsible for?

A

leads to temporal lobe, amygdala, & hypothalamus. They are responsible for cough, salivate, sneeze or vomit in response to odors. emotional responses to odors

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89
Q

For what does the cerebral cortex sends feedback to bulb cells

A

changing quality &; significance of odors when hungry

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90
Q

what are the olfactory projection pathways ?

A

Hippo campus (conscious perception), Amygdala (emotional response), Reticular formation (visceral response), olfactory cortex of temp. lobe (conscious perception )

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91
Q

True or false Receptor cells for olfaction form olfactory mucosa. What does the mucosa cover ?

A

True , superior concha and nasal septum

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92
Q

What are olfactory cilia called?What are they for?

A

olfactory hairs . The cilia are binding sites for odors (volatile molecules)

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93
Q

True or false Olfactory receptor cells are neurons with a modified dendrite

A

True

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94
Q

What kind of neurons are olfactory hairs? (polar)

A

They are bipolar neurons that transduce chemical sensations into neural signals

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95
Q

What nerves are the only kind to be directly exposed to the external environment?

A

olfactory hairs

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96
Q

What are the other cell types present in olfactory epithelium(in mucosa ).

A

supporting cell, basal cell, olfactory cell

97
Q

What is the purpose for the supporting cell?

A

provides physical and nutritive support, its ciliated

98
Q

What is the purpose for the basal cell?

A

glial element (glue) they also differentiate into new olfactory cells every 60 days.

99
Q

Granule cells receive signals from the cortex and are ________ to the mitral cells (causing adaptation)

A

Inhibitory

100
Q

The axons from what cells form bundles called the olfactory tract

A

the mitral and tuft cells

101
Q

What is sound?

A

Any audible vibration of molecules

102
Q

molecules in the air connect with what in the ear making it vibrate?

A

Tympanic membrane

103
Q

True or false sounds grater than 90 decibles (dB) can cause damage

A

true

104
Q

what gives us sense of pitch?

A

frequency of the ear vibrating

105
Q

What is “loudness” ?

A

perception of sound intensity

106
Q

How are waves categorized?

A

frequency and intensity

107
Q

What is frequency?

A

greater the frequency the higher the pitch, measured in hertz (cycles per sec.)

108
Q

What is intensity ?

A

directly related to amplitude of sound waves, measured in decibles.

109
Q

What part of the ear directs vibrations down the auditor canal ?

A

Auricle/pinna (your whole outer ear)

110
Q

What are the three regions of the ear?

A

Outer, middle, and inner.

111
Q

What is the purpose of the outer and middle ear?

A

transmission of sound into inner ear.

112
Q

What is the purpose of the inner ear?

A

converts sound into fluid motion and then to electrical impulses(action potential)

113
Q

Why is the tympanic cavity thats filled with air connected to the nasopharynx?

A

to equalize air pressure on both sides of eardrums . Done by yawning and swallowing.

114
Q

True or false the stapes is attached to the eardrum ?

A

True

115
Q

True or false the incus and stapes is attached to the oval window

A

True

116
Q

How is the cochlea protected ?

A

Tensor tympani pulls eardrum inward to reduce mobility of ear bones .

117
Q

What is the smallest muscle in the skeletal body?

A

stapedius , connects to stapes and reduces its action . Contracts before speaking and chewing.

118
Q

What CN innervates the stapedius muscle?

A

CN VII facial nerve

119
Q

What CN innervates the Tensor Tympani muscle?

A

CN V Trigeminal , madndibular branch(V3)

120
Q

What is a Myringotomy tube for?

A

Equalization of air behind the eardrum so it doesn’t build up with fluid and cause hearing disorders.

121
Q

How is sound in the inner ear produced ?

A

vibrations of ossicles and basilar membrane under hair cells

122
Q

What portion of the cochlea is responsible for the ascending fluid (perilymph)?

A

scala vestibuli

123
Q

What portion of the cochlea is responsible for the descending fluid (perilymph)?

A

scala tympani

124
Q

what structure is found inside the cochlear duct?

A

Organ of cordi

125
Q

What is the name of the fluid inside the cochlear duct (cochlear duct is in between the scalas) ?

A

endolymph

126
Q

How are stereocilia depolarized ?

A

Movement of the tectorial membrane moves the embedded cilia tips causing an influx of potassium which depolarizes and releases NT. stimulating sensory dendrites

127
Q

What NT is released when stereocillia are depolarized ?

A

glutamate

128
Q

What lobe is the site of conscious perception ?

A

Temporal

129
Q

Define equilibrium

A

control of coordination and balance

130
Q

Define static equilibrium

A

perception of head orientation perceived by macula

131
Q

Define dynamic equilibrium

A

perception of motion or acceleration perceived by macula and crista

132
Q

What does the vestibular apparatus maintain?

A

maintains body at equilibrium and stabilize the eyes relative to the environment .

133
Q

What two structures does the vestibular apparatus have ?

A

otolithic organs(static) and semicircular canals(dynamic)

134
Q

What structures does the macula consist of?

A

sensory hair cells and supporting cells (sustentaculare cells ) for keen vision and contains fovea

135
Q

Define Utricle

A

irregular oblong membraneous sac on the medial wall of vestibule , most sensitive to horizontal acceleration.

136
Q

What is the otolithic membrane and where does it sit?

A

gelatinous membrane, produced by sustenticular cells, that sits on top of sensory cells.

137
Q

What are otoliths?

A

Crystals of calcium carbonate that are sensitive to horizontal movements

138
Q

Define saccule

A

flattened membranous sac located in the medial wall of the bony vestibule. Most sensitive to vertical movement

139
Q

What direction is the saccular macula most sensitive to?

A

Vertical, Up, down, forward, and back

140
Q

Describe Crista Ampullaris

A

Hair cells buried in a mound of gelatinous membrane

141
Q

True or Flase ?Hair cells of macula sacculi, macula utriculi & semicircular ducts synapse on vestibular nerve

A

True

142
Q

What is vision (sight)?

A

Perception of light emitted or reflected from objects in the environment.

143
Q

What do tarsal glands secrete?

A

Oil that reduces tear evaporation (white krusties in the morning)

144
Q

True or False the conjunctiva is highly vascular

A

True

145
Q

What are the three layers of the tunic (eyeball)?

A

Tunica Fibrosa, Tunica Vasculosa, Tunica Interna

146
Q

What consists of the Tunica Fibrosa?

A

Scalera and cornea (avascular)

147
Q

What consists of the Tunica Vasculosa?

A

Choroid, ciliary body and iris (Vascular)

148
Q

What consists of the Tunica Interna?

A

Retina

149
Q

what is aqueous humor?

A

serious fluid produced by ciliary body that flows from post. chamber through pupil to ant. chamber

150
Q

what reabsorbs left over aqueous humor ?

A

Canal of schlemm (Sclera Venous sinus)

151
Q

What is deep to the sclera and is highly vascular?

A

Choriod (vascular tunic)

152
Q

The choroid continues to the anterior portion of the vascular tunic and becomes what structure?

A

Ciliary body

153
Q

What secrets aqueous humor?

A

Ciliary processes in the ciliary body

154
Q

What part of the ciliary body are the suspensory ligaments?

A

Zonular fibers

155
Q

What is the function of the ciliary muscle?

A

Contracts and relaxes to alter the shape of the lens to adapt for near or far vision

156
Q

What is the function of the iris ?

A

Regulates the amount of light entering the pupil (suspended between the cornea and lens)

157
Q

Describe optic disc

A

Site where the optic nerve and retinal artery and vein enter and exit the eye (blind spot)

158
Q

What does the neural apparatus include?

A

The retina and optic nerve

159
Q

What is the function of melanin in the retina ?

A

Absorbs stray light and prevents reflection allowing for sharp images

160
Q

What are the three layers of retinal neurons from superficial to deep?

A

Photoreceptor layer, Biopolar cell layer, and Ganglion cell layer

161
Q

What are the two types of photoreceptors ?

A

Rods and cones

162
Q

Explain rods

A

low light threshold, good for dim light, NO COLOR, and shades of gray

163
Q

Explain cones

A

higher light threshold, color vision, difficult seeing in dim light

164
Q

True or False? The loss of cones causes visual legal blindness

A

True

165
Q

True or False? There are more rods than cones

A

True, 120 million rods to 6 million cones

166
Q

Define Macula Lutea

A

Exact center of posterior retina

167
Q

Define Central Fovea

A

Small depression in center of Macula Lutea that contain only cones.

168
Q

True or False? the Macula Lutea contains ONLY cones

A

True

169
Q

Where is the lens located?

A

Behind the pupil and iris

170
Q

What divides the internal eye into Anterior and Posterior cavities?

A

The lens

171
Q

What is the purpose of aqueous humor and where is it found?

A

Nourishes the lens, provides intraocular pressure and is found in the anterior cavity of the interior eye

172
Q

What maintains the shape of the eyeball and prevents it from collapsing?

A

Intraocular pressure

173
Q

What is the function of vitreous body ?

A

A jelly-like substance that contributes to intraocular pressure that holds the retina flush against the choroid

174
Q

True or False? Vitreous body does not undergo constant replacement

A

True

175
Q

Define hyaloid canal

A

narrow channel that was occupied by the hyaloid artery in the fetus

176
Q

What type of cells remove debris from the vitreous body?

A

Phagocytic cells

177
Q

Image formation involves what four things?

A

Refraction, accommodation, light control, and convergence

178
Q

True or False? The cornea refracts more light than the lens

A

True

179
Q

True or False? Lens shifts focus between near and distinct objects

A

True

180
Q

What kind of vision is Emmetropia?

A

Normal distant vision

181
Q

what is Myopia?

A

Nearsightedness, focus power to strong, or eyeball to long,

182
Q

what is hyperopia ?

A

Farsightedeness, focus power to weak, or eyeball to short.

183
Q

Define Astigmatism

A

Caused by an unevenly shaped eyeball, cornea, or lens

184
Q

Define Presbyopia

A

At an old age the lens loses elasticity and its ability to accommodate

185
Q

Define Cataracts

A

clouding of the normally clear lens of the eye

186
Q

Define convergence

A

Both eyes looking at the same object

187
Q

Describe the Photopupillary reflex

A

Both pupils constrict when one eye is illuminated (parasympathetic reflex)

188
Q

What does the constriction of the pupil prevent ?

A

doesn’t allow peripheral light rays in and reduces aberrations(blurry edges)

189
Q

How is the lens accommodated ?

A

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
Q

What kind of lens do you need to correct hypertropia?

A

convex lenses

191
Q

What kind of lens do you need to correct Myopia ?

A

concave lenses

192
Q

Define photo-pigments, where are they found?

A

integral proteins in the plasma membrane of the outer segment

193
Q

Define rhodopsin

A

photopigment in rods (outer segment)

194
Q

Define photopsin or iodopsin

A

there are three types one for each type of cone

195
Q

What two parts do all photopigments contain ?

A

opsin, and retinal

196
Q

What does opsin do?

A

one for each color and one for rhodopsin , 4 all together. They absorb different wavelengths (different colors)

197
Q

What wavelength is perceived as Red by opsin?

A

long wavelengths

198
Q

What wavelength is perceived as Green by opsin?

A

middle wavelengths

199
Q

What wavelength is perceived as Blue by opsin?

A

short wavelengths

200
Q

What does retinal in a photopigment do? Why do they store vitamin A?

A

The part of the photopigment that absorbs light. Vitamin A is stored in photopigmented cells for regeneration in rods

201
Q

Why do you feel pain when you turn on a bright light in the middle of the night ?

A

Your pupil was dilated at the time you were exposed to the bright light and over stimulated your retina.

202
Q

In dark adaptation why cant you see well at first when the lights are turned off?

A

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
Q

Upon illumination what happens to the CNG channels?

A

The CNG channels close and the photoreceptor hyperpolarizes

204
Q

In the dark what happens to the CNG channels?

A

The CNG(in the plasma membrane) channels are kept open by cGMP and the cell depolarizes.

205
Q

What part of the photopigment is activated with bleaching.

A

Opsin

206
Q

List the chain of events that causes the CNG channels to close when light enters the eye

A

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
Q

Bipolar cells synapse with what other 3 cells

A

rods, cones, and ganglion cells

208
Q

What are the largest neurons of the retina?

A

Ganglion cells

209
Q

What are horizontal and amacrine cells responsible for?

A

enhancing perception contrast, edges of objects, and changes in light intensity.

210
Q

Describe the shape of rhodopsin when it is cis-retinal

A

the shape is bent

211
Q

Describe the shape of rhodopsin when it is transretinal?

A

it is straight , becomes straight when bleached

212
Q

What is the shape of rhodopsin when it is bleached?

A

It is straight, trans-retinal

213
Q

How does a patient fail the webers test?

A

they fail to hear the tuning fork equally in both ears

214
Q

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 ?

A

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
Q

What do rods produce in the dark that causes no signal in the optic nerve?

A

a steady ion flow that causes a IPSP

216
Q

What causes the dark current to cease ? (in the rods)

A

When the light hits the rods the dark current ceases and no longer inhibits EPSP.

217
Q

Photorecpetors are derived from stem cells that produced what neuroglia?

A

ependymal cells

218
Q

Bipolar are __ order neurons and Ganglion are __order neurons.

A

Bipolar 1st ganglion 2nd . Everything converges down to the ganglion neurons that make up the optic nerve.

219
Q

What is the ratio of rods to bipolar cells? How does this ratio affect your vision?

A

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
Q

Photopic is to ____ vision and Scotopic is to____ night vision.

A

Photopic is to day vision, Scotopic is to night vision.

221
Q

True or false there is are rod cells in the fovea

A

False

222
Q

True of false each foveal cone cell has its own private line to the brain

A

True, no neural convergence.

223
Q

True or false foveal cones are less sensitive to light intensity.

A

True

224
Q

Do nocturnal vertebrates have cones ?

A

No they only have rods

225
Q

What is the perception of color?

A

perception of color is based off of a mixture of nerve signals.

226
Q

True or false is color blindness hereditary?

A

Yes, males carry the gene and in general 8% has the recessive gene .

227
Q

Where doe conscious visual sensation occur?

A

Visual cortex

228
Q

Where are the 3rd order neurons for the eyes?

A

lateral geniculate nucleus of the thalamus

229
Q

what does the association areas in parietal and temporal lobes process what types of visual data?

A

object location, motion, color, shape, boundaries, and store visual memories (recognize printed words).

230
Q

Macular degeneration is most common in who?

A

old people and is the leading cause of blindness

231
Q

What causes Macular degeneration?

A

degeneration of pigmented epithelium leading to leakage of fluid behind macula and fovea causing white spots.

232
Q

Why cant ppl with macular degeneration read or see fine print?

A

The cones of the fovea die causing central visual loss.

233
Q

what causes glaucoma

A

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
Q

What kind of treatment is essential for glaucoma ?

A

release of intraocular pressure

235
Q

Describe Diabetic Retinopathy

A

side affect of diabetes that can cause blindness by blood vessels multiplying in uncontrollable ways.

236
Q

What is the most common treatment of Diabetic Retinopathy ?

A

Laser treatment for stopping blood vessel proliferation and leakage of fluid into the retina

237
Q

True or false Retinitis Pigmentosa is hereditary .

A

True

238
Q

Why do patients with Retinitis Pigmentosa have tunnel vision?

A

The rods of the peripheral retina degenerate , causing night blindness, only the cones in the fovea are left resulting in the tunnel vision

239
Q

What causes the rods to die in a patient with Retinitis Pigmentosa?

A

Thinned blood vessels at the optic nerve head (less blood supply causing atrophy of rods)

Anatomy & physiology 102 (13 decks)

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