Exam 2 Flashcards
1
Q
When light strikes a photoreceptor, what happens? And what happens to glutamate?
A
Hyperpolarizes; and decreased release of glutamate
2
Q
The greatest refraction of light in the eye occurs at which interface?
A
Air-cornea
3
Q
In a 60 year old, the lens strength can vary by how many diopters?
A
0
4
Q
In a young child, the lens strength can vary by how many diopters?
A
14
5
Q
What is a diopter?
A
It is a unit of measurement = 1 meter of focal length
6
Q
When reading a book what is the refractive power of your lens like?
A
High
7
Q
What condition is correlated with a focal point in front of the retina?
A
Myopia, or near sighted
8
Q
What condition is correlated with a focal point behind the retina?
A
Hyperopia, or far sighted
9
Q
What is Astigmatism and what part of the eye is more commonly effected?
A
irregular shape, and cornea more common then lens
10
Q
What is Emmetropia? What are the ciliary muscles like in a patient with this?
A
Normal vision; relaxed in distant vision
11
Q
What kind of lens would fix hyperopia
A
convex
12
Q
What kind of lens would fix myopia
A
concave
13
Q
How does light pass to the long slender cones relatively unimpeded in the fovea centralis?
A
Blood vessels and cells are displaced laterally
14
Q
What is presbyopia
A
loss of elasticity of lens with age
15
Q
What area of the eye has the greatest acuity?
A
fovea centralis
16
Q
The central fovea area of greatest acuity is composed almost entirely of what?
A
Long slender cones
17
Q
As you move from fovea centralism to periphery of retina does visual acuity decrease? And if so, how much?
A
Yes; more 10 fold
18
Q
What causes the natural blind spot in your eye?
A
lack of receptors in the optic disc
19
Q
What is stereopsis
A
binocular vision (eyes separated by 2 inches)
20
Q
What secretes your aqueous humor?
A
the ciliary body
21
Q
What is normal intraocular pressure produced by the aqueous humor?
A
12-20 mmHg
22
Q
What is Glaucoma, and if left untreated what can occur?
A
Increased intraocular pressure; compression of optic nerve which can lead to blindness
23
Q
True or false, the retina is not considered an extension of the peripheral CNS
A
false
24
Q
What are the only retinal cells that can generate action potentials?
A
ganglion cells
25
What does light break down in the rods?
rhodopsin
26
What does light break down in cones?
cone pigments
27
True or false as rhodopsin is broken down in retina, photoreceptor cells hyper polarize
true
28
True or false as rhodopsin is broken down in retina, and photoreceptor cells hyper polarize more glutamate is released?
false, less glutamate is released
29
When it is dark out, how do your retina cells react? Is there more neurotransmitter released?
the cells depolarize, and yes more is released
30
When it is bright out, how do your retina cells react? Is there more neurotransmitter released?
the cells hyper polarize; and no less is released
31
When there is an increase in glutamate (dark out, rods and cones depolarized) what happens to the "off" bipolar cells
depolarized, "On" cells opposite
32
When there is an decrease in glutamate (bright out, rods and cones hyperpolarized) what happens to the "off" bipolar cells
hyperpolarized, "On" cells opposite
33
Bipolar cells can connect to which two kinds of cells
amacrine or ganglion
34
"on" bipolar cells are known as ______ bipolars
invaginating
35
"off" bipolar cells are known as _______ bipolars
flat
36
What are the three subtypes of ganglion cells?
P (x); M (y); W
37
Which is more numerous P (x) or M (y) ganglion cells
P (x) around 55%
38
Where do P (x) ganglion project on to
Parvocellular layer of lateral geniculate nucleus (LGN)
39
Where do M (y) ganglion project on to
Magnocellular layer of lateral geniculate nucleus (LGN)
40
What kind of cells are non-spiking inhibitory interneurons, and responsible for center-surround antagonism
horizontal cells
41
What kind of cells receive input from bipolar cells and project onto ganglion cells
Amacrine cells
42
In the center field, where do photoreceptors synapse?
Directly onto bipolar cell
43
In surround field, where do photoreceptors synapse?
Gain access to bipolar cell through horizontal cells
44
True or false, center field and surround field act oppositely (when one is on the other is off)
True
45
If both center field and surround field is stimulated, what happens
No net response
46
In fovea, what is the ratio for cone to bipolar cell to ganglion?
1:1:1
47
In peripheral retina what is the ratio from rods to bipolar cells to ganglion?
As many as 1000:100:1
48
True or false, in the presence of darkness for an extended period of time light sensitive pigments do not adapt
false, they do adapt (cone 100 fold)
49
What are the 3 populations of cones?
Blue sensitive, Green sensitive, and Red sensitive
50
Is color blindness genetic? If so, is it transmitted paternally or maternally? What chromosome is it carried on? What kind is most common?
Yes; maternally; X chromosome; Red-Green (blue is rare)
51
What is Protanope
Loss of red cones
52
What is Deuteranope?
Loss of green cones
53
In bright light, what is responsible for constriction of pupil, and what is this process called?
Parasympathetic stimulation; miosis
54
In darkness, what is responsible for dilation of pupil, and what is this process called?
Sympathetic stimulation; mydriasis
55
What kind of cone has the shortest wave length?
Blue
56
What is the Suprachiasmatic nucleus associated with?
Biological clock
57
What is the Pretectal nuclei associated with?
Reflex movement of eyes
58
What is the Superior Colliculus associated with?
Rapid directional movement of both eyes/ Orientation
59
What part of the primary visual cortex is associated with motion dependent and orientation like simple cells
Complex cells
60
Name the 3 visual association cortex pathways and describe what each is associated with in relation to visual information
Parvo-interblob- high resolution static form perception, Blob- Color, Magno- Movement and depth
61
Where does the old visual pathway project on to? What kind of information is it associated with?
Superior colliculus; locating objects in visual field, subconscious and blindsight
62
Where does the new visual pathway project on to? What kind of information is it associated with
The Cortex; Consciously recognizing objects
63
What is Blindsight?
Close your eyes and pick up objects, can you tell their orientations? This subconscious ability is called blindsight
64
In dB what is the range for a whisper to your threshold of pain and what are the examples in between?
20 to 160 (60 normal convo, 100 concert, 130 discomfort)
65
In a young adult, what is the range frequency in Hz we can hear
20-20,000
66
What is the frequency of greatest acuity in hearing (Hz)
1000-4000
67
Sound waves against the tympanic membrane create sound waves in the cochlear fluid due to the function of what?
Ossicular function
68
Name the 3 "scala's" of the cochlea
Scala vestibuli, Scala media, Scala tympani
69
Which Scala of the cochlea is associated with the oval window and filled with perilymph?
Scala Vestibuli
70
Which Scala of the cochlea is separated from Scala tympani by basilar membrane, and filled with endolymph (K+)
Scala Media
71
True or false Scala media is filled with endolymph (K+) that baths the tops of hair cells
True
72
Which Scala of the cochlea is associated with round wind, and filled with perilymph (CSF) that baths lower bodies of hair cells
Scala Tympani
73
How does the Cochlea function starting with mechanical vibrations
Mechanical vibrations cause action potentials in fluid toward CN VIII, these vibrations in fluid cause movement of basilar membrane
74
True or false, different sound frequencies displace different areas of basilar membrane
True
75
What kind of hair cells are near oval window (base) and what frequencies are they best suited for?
Short and thick; higher frequencies
76
What kind of hair cells are near helicotrema (apex) and what frequencies are they best suited for?
Long and slender; lower frequencies
77
What is a Fourier analysis? What anatomical structure acts as one?
Breaking complex wave into its components, phases, and frequencies; the Cochlea
78
What features of anatomy are involved in the air conduction pathway
External ear canal, middle ear, and inner ear
79
What does the bone conduction pathway involve
Direct stimulation of cochlea through vibration of skull
80
Reduced hearing from ossicles would be associated with what kind of hearing loss
Air conduction loss
81
Reduced hearing from cochlea would be associated with what kind of hearing loss
sensory neural loss
82
Which part of the auditory cortex is associated with high frequency sounds?
posterior
83
What part of the auditory cortex is associated with low frequency sounds
anterior
84
In sound localization, what brainstem nuclei is associated with time lag between the ears?
Medial superior olivary nucleus
85
In sound localization, what brainstem nuclei is associated with difference in intensities of sound in both ears?
Lateral superior olivary nucleus
86
True or false, taste neuroepithelium consists of taste buds distributed over tongue, pharynx, and larynx
true
87
What is a taste bud?
40 to 50 modified epithelial cells grouped into barrel shapes, each containing a small pore
88
How often do taste buds regenerate?
Weekly basis
89
The anterior 2/3 of tongue is innervated by what CN
VII
90
The posterior 1/3 of tongue is innervated by what CN
IX
91
Base of tongue and palate is innervated by what CN
X
92
Where do all of the cranial nerves that innervate tongue terminate in CNS?
Nucleus tractus solitarius (NTS)
93
What kind of taste is linked with G-protein receptors?
Sweet, bitter, and Umami
94
What kind of taste is linked to ion channels?
Salts and Sour
95
What is the least understood special sense?
Olfaction
96
What does microsmatic mean?
poorly developed sense of smell
97
Once taste information synapses in Nucleus tractus solitarius (NTS) where does it go?
VPM of thalamus
98
From VPM of thalamus, where does taste information end in CNS
lower tip of post central gyrus in parietal cortex
99
What part of the olfactory is associated with olfactory receptors?
Olfactory epithelium
100
What are of nose responds highly to pheromones
Vomernonasal organ or Jacobson's organ
101
What kind of nerve cells are associated with olfactory cells? Do they project anything?
Bipolar; yes hairs into nasal cavity
102
What are the bipolar nerve cells of olfactory connected to?
olfactory bulb via cribiform plate
103
What do cells in Bowman's glands do?
secrete mucus
104
Is there such a thing as primary order?
No, order is subjective
105
What is Anosmia?
Order blindness
106
Are Mitral and Tufted cells inhibitory or stimulating in olfactory senses?
Stimulating
107
What are the two inhibitory olfactory cells
Granule and Periglomerular
108
The medial olfactory pathway relays basic information to what part of brain?
Hypothalamus
109
The lateral olfactory pathway travels to what part of brain? And is unique sensory pathway because?
Pyriform cortex and a sensory pathway that doesn't relay through thalamus
110
New olfactory pathway passes through what part of the brain? Associated with what?
Thalamus, analysis of order
111
The anterior olfactory nucleus has what function?
Processing information in olfactory bulbs
112
The amygdala and olfactory tubercle has what function?
Emotional, endocrine, and visceral response to order
113
Pyriform and periamygdaloid cortex has what function
Olfactory perception
114
What hold olfactory memories?
Rostral entorhinal cortex
