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CNB > Exam 2 > Flashcards

Exam 2 Flashcards

1
Q

action potential is 100 mV, which is approximately ____ times greater than a single EPSE

A

100

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2
Q

action potential lasts approximately…

A

1 msec

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3
Q

action potential goes from…

A

rest to the rising phase to the overshoot, falling phase, and then the undershoot

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4
Q

action potential is all or none, meaning…

A

that theres either an action potential or these isnt, no inbetween or incomplete ones

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5
Q

the Na+ channel is a single peptide with…

A

four separate domains

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6
Q

each of the 4 domains of the Na+ channel has___ transmembrane alpha helices that are labeled ____

A

6; s1-s6

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7
Q

the pore loop of the Na+ channel is located between…

A

S5 and s6

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8
Q

the pore loops of the Na+ channel act together as…

A

a selectivity filter

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9
Q

the s4 alpha helix has…

A

+ amino acids that act as the voltage sensor and detect the voltage across the membrane

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10
Q

the alpha helix in the Na+ channel that detects the voltage changes is….

A

the s4 alpha helix

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11
Q

the s4 voltage sensor of hte Na+channel physically opens when…

A

the voltage reachs -40 mVor higher, which then allows Na+ to enter the cell down its concentration gradient

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12
Q

the s5 and s6 selectivity filter of the Na+ channel is selective by…

A

being shaped exactly for the ion the pore channel is a gate for. so in this case it is the exact size of an Na+ moecule paired with 1 water molecule. hydrated K+ ions don’t fit because theyre too large.

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13
Q

the Na+ channel has a resting voltage of…

A

-65 mV

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14
Q

once Na+ flows into the cell, ____ blocks the Na+ channel so that it can fall back to rest

A

the globbular “ball” protein portion of the Na+ channel. once back to rest the ball swings away so the pore can close again

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15
Q

local anestetics work by…

A

getting into th epore channel of Na+ so it is physically blocked so no action potential can occur so no pain is felt.

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16
Q

teh two types of potassium channels are the…

A

leak channels (open all the time/not voltage gated) which are responsible for resting membrane potential. the other is the voltage gated K+ channel (delayed rectifiers) that open with a delay.

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17
Q

the voltage gated K+ channels are called “delayed rectifiers” because…

A

they sense a voltage change during the rising phase but do not open right away. when they do open, K+ flows outward. these are responsible for the falling phase of the action potential (becomes more negative as a result of K+ leaving the cell)

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18
Q

undershoot follows the…

A

falling phase

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19
Q

during the undershoot, ____ channels are open

A

leak and K+ gated channels which means theres a larger K+ conductance and therefore the voltage goes down below resting to the EK+

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20
Q

the cell goes back up to resting from an action potential when…

A

the K+ gated channels close and there is no longer a loss of + charge from the leaving of K+

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21
Q

during the rising phase and overshoot of the action potential, ___ is open so there is a net inflow of Na+

A

Na+ gated channels

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22
Q

over evolution, the coretex has expanded to have…

A

an outer layer, large surface area and be highly convoluted

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23
Q

because the cortex has expanded so much, there is space in the brain for other functions such as…

A

cognition, thinking, planning, strategy, etc

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24
Q

the central sulcus is the divide betweem the…

A

frontal and parietal lobes

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25
Q

in the mammalian brain, the cerebrum has ___ sections

A

two sections

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26
Q

the left side of the cerebreum is responsible for…

A

recieving the sensory info for the right side of the body - there is a crossover in the brain

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27
Q

the cerebellum “litte brain” as much more tightly packed neurons than the…

A

cerebrum although the two has the exact same number of neurons

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28
Q

the left side of the cerebellum recieves infromation from….

A

the left side of the body, there is NO crossover in this section of the brain

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29
Q

the brain stem is responsible for regulating…

A

breather, conciousness, temperature control, ad other vital functions

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30
Q

the further into the brain you travel, the _____ the functions are

A

more basic

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31
Q

the spinal cord functions in…

A

sending info into and from the brain

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32
Q

there are ____ meningal membranes in the human brain

A

3

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33
Q

the meningies in the brain are…

A

the dura matter, the arachnoid membrane, and pia matter

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34
Q

a subdural hematoma is when blood collects in the subdural space between…

A

the dura matter and teh arachnoid membrane

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35
Q

pia matter is located…

A

right on top of the brain

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36
Q

the subarachnoid space is filled with…

A

cerebrospinal fluid

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37
Q

the ventricular system is the…

A

fluid surround the brain and spinal cord, helps protect the brain

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38
Q

cerebral spinal fluid is protected by…

A

tissues

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39
Q

the choroid plexus in the lining of the ventricles functions in…

A

filtering blood that is then reabsorbed into the subarachnoid space

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40
Q

the retina develops from the…

A

optic vesicles

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41
Q

the tekencephalic vesicles develop into the…

A

cerebral hemispheres

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42
Q

the edge of the optic cup becomes the…

A

retina

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43
Q

the optic stalk becomes the…

A

optic nerve

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44
Q

neural tube birth defects occur when the…

A

neural tube does not close corectly (ie spina bifida and anencephalo)

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45
Q

spina bifida is when…

A

the spine does not close or develop properly

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46
Q

anencephalo occurs when there are insuffient levels of folic acis and causes…

A

neural tube defects

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47
Q

having sufficent levels of folic acid during fetal development can prevent 70-90% of all…

A

neural tube defects

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48
Q

the neural tube differentiates into the ___ brain

A

forebrain

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49
Q

the thalamus is in the…

A

center of the brain

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50
Q

the thalamus acts as…

A

a relay station for sensory systems except for smell. your thalamus is turned off when youre asleep.

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51
Q

the superior colliculus…

A

recieves visual info, moves the head/eye towards visual stimulus

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52
Q

the inferior colliculus…

A

recieves auditory stimulus, moves the head towards sound

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53
Q

the cerebral aqueduct is where…

A

cerebrospinal fluid circulates

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54
Q

the tegmentum has the sibstantia nigra which plays a role in…

A

movement, this is the area damaged in aprkinsons disease

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55
Q

the tectum includes the…

A

superior colliculus, the inferior colliculus and the cerebral aquesduct

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56
Q

the midbrain consiststs of the…

A

tectum and the tegmentum

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57
Q

the dorsal portion of the hindbrain becomes teh…

A

cerebellum which functions in coordination of movement, motor memory storage

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58
Q

the dorsal horn of the spinal column send…

A

sensory info to the brain

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59
Q

the ventral horn of the spinal column sends…

A

motor info to muscle cells

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60
Q

the most common neurodegenerative disease is…

A

alzheimers

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61
Q

symptoms of AD include…

A

memory problems,language impairment, disorientation, problems with abstract thinking, judgement problems, and personality changes that all result from the death of brain cells

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62
Q

in AD neurofibillary tangles accumulate intracellularly and ____ forms extracellularly

A

amyloid plaques

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63
Q

the neurofibillary tangles and amyloid plaques of AD cause cell death i the brain and is most severe in the…

A

hippocampus

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64
Q

amyloid plaques are composed of…

A

Beta amyloid which is a peptide about 39-42 amino acids long, it is cut from the amyloid precursor protein (APP) a transmembrane protein

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65
Q

beta amyloid (aka amyloid beta, AB) is cut from APP by…

A

beta and gamma secretases

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66
Q

in AD, normal amounts of amyloid beta are produced but…

A

they are not cleared at normal rates

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67
Q

in normal function amyloid beta works to…

A

regulate synaptic activity (dampens it)

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68
Q

there is evidence the amyloid beta may…

A

inhibit yeast infections

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69
Q

just as in CTE, in AD tangles of the tau protein becomes…

A

hyper phosphorylated, microtubules disassemble, axonal transport stops, and eventually neurons die

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70
Q

the cortex and hippocampus shrink in…

A

AD

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71
Q

the gene for APP (on chr 21, people with downs syndrome have higher risk), PSEN-1, PSEN-2, and APOE all impact…

A

AD

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72
Q

PSEN-1 and PSEN-2 both code for proteins that are a componet of gamma secretase which…

A

makes more of the 42 amino acid beta amyloid which builds up easier because its larger

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73
Q

APOE (apolipoprotein E) codes for a component of VLDL and functions to…

A

remove cholesterol from the blood and amyloid beta plaques from the brain. different forms of the gene have different benefits for fighting AD. E2 is rare in population btu helps fight AD, e3 is most common and has no effect on AD, e4 is a risk factor because it has a low efficencey

74
Q

acetylcholine esterase inhibitors normally breaks down ACh but the drug…

A

inhibits ACh breakdown so that you have more transmitter in teh synaptic cleft which helps to improve cognition, mood, and behavior in AD patients

75
Q

behaviorla and dietary risk factors for AD include…

A

high calorie diet, high fat diet, sedentary lifestyle, low education level, history of head trauma

76
Q

antiboides against amyloid plaques worked well in mice but…

A

did not work in humans, instead people develped increased fluid pressure in and around the brain, the brain became inflammed, and there was too large of an immune response in the brain

77
Q

the cancer drug targretin turns on the APOE gene and in the mouse models…

A

amyloid plaque levels droped by 25% within 6 hours and by 50% in 72 hours. also restored some normal behaviors. currently in clincal trials for humans

78
Q

the somatic sensory system is responsible for…

A

sense of touch, vibration, pain, temperature, and proprioception

79
Q

primary afferent axons bring sensory info to the brain and their cell bodies are in…

A

the dorsal root ganglion, one part of the axon then goes out to the skin/muscle/tendon and the other portion goes to the spinal cord via the dorsal roots

80
Q

axon and non neural tissue have free nerve endings that detect..

A

pain and temperature, they are the only ranched axons here

81
Q

the axons in the skin contain…

A

mechanosensitive ion channels that respond to stretching or tension in the cell membrane

82
Q

primary afferent axons vary in…

A

diameter and myelin composition. the fastest axons have the greatest diameter and myelin

83
Q

the fastest primary afferent axon is…

A

the A alpha that send information about body position from muscles and tendons

84
Q

the second fastest primary afferent axons are…

A

A beta, which function to carry info about touch, vibration, and pressure to the brain

85
Q

the slowest primary afferent axons are…

A

c fibers, the smallest of these axons that lacks myelin. they function in sending info to the brain about pain, temp, and itch

86
Q

the second slowest primary afferent axons are…

A

A delta which carry information about pain and temp

87
Q

A alpha and A beta send nfromation to the brain via the ___ pathway

A

the dorsal column-medial lemniscal pathway

88
Q

the dorsal column-medial lemniscal pathway for A beta and A alpa axons runs…

A

up the spinal column on the same side they enter where they then go into the ipsilateral dorsal column. then it reaches the first synapse at the brain stem. the second order neuron then crosses over to the other side and runs up to relay in the ventral posterior thalamus. the 3rd order neuron then goes to the primary somatosensory cortex.

89
Q

the primary somatosensory cortex (s1) is located…

A

in the parietal lobe behind the central sulcus in the post central gyrus. this is bilateral and there is crossover (left side of body=right somatosensory cortex)

90
Q

Penfield’s map shows…

A

the location of the sensory input for each part of the body in the brain

91
Q

hands, face,and fingers are overrepresented in S1 which is why…

A

they are much more sensitive

92
Q

teh two slowest axons, c fibers and A delta, carry information about…

A

pain

93
Q

the first pain detector is…

A

a delta , which causes a sharp pain

94
Q

the second pain detect is…

A

the c fibers, causes dull, throbbing pains and burning sensations

95
Q

both A delta and c fibers have ion channels that respond to…

A

a lot of mechanical stimulation: it takes a lot of pressure to actually feel pain instead of pressure in a given area. they also respond to temperature when its high enough to cause damage (ie: burns) and to chemicals if its something corrosive like lactic acid and histamine

96
Q

A delta and c fibers have 6 different…

A

transient receptor channels (TRP)

97
Q

the TRP of a delta and c fibers have…

A

different sensitivities to temperature: some detect cold and some detect heat th cold receptors can also be activated by menthol and heat receptors can also be activated by capsaicin

98
Q

the pathway that the c fibers and A delta follow is…

A

the spinothalamic pathway

99
Q

in the spinothalamic pathway, axons…

A

synapse as soon as they enter the spinal column. then the second order neurons cross over to the contralateral side and ascend to the thalamus. the 3rd order neurons then go from the thalamus to the primary somatosensory cortex

100
Q

if someone has unilateral damage on the right side of their body on the spinal cord, what sensations would you expect to be lost?

A

the person would lose the ability to detect touch, vibration, 2 point discrimination and proprioception below the lesion on the right side/SAME SIDE of the body and they would lose the ability to detect pain and temperature on the left side/opposite side of the body below the lesion

101
Q

pain is reduced by…

A

the simulataneous activation of mechanoreceptors (ie rubbing your skin where it hurts reduces the pain. this happens because A alpha and A beta axons activate inhibitory interneurons that reduce the activity of the spinothalamic tract

102
Q

the descending pain control pathway controls…

A

how much pain goes into the brain

103
Q

stimulation of PAG in the midbrain produces pain relief by…

A

projecting to the dorsal horn of the spinal cord which then activates the inhibitory interneurons in the spinothalamaic tract. morphine works by binding to the opoid receptors in the PAG which lead to inhibitiion. natural endorphins also work this way

104
Q

teh two slowest axons, c fibers and A delta, carry information about…

A

pain

105
Q

the first pain detector is…

A

a delta , which causes a sharp pain

106
Q

the second pain detect is…

A

the c fibers, causes dull, throbbing pains and burning sensations

107
Q

both A delta and c fibers have ion channels that respond to…

A

a lot of mechanical stimulation: it takes a lot of pressure to actually feel pain instead of pressure in a given area. they also respond to temperature when its high enough to cause damage (ie: burns) and to chemicals if its something corrosive like lactic acid and histamine

108
Q

A delta and c fibers have 6 different…

A

transient receptor channels (TRP)

109
Q

the TRP of a delta and c fibers have…

A

different sensitivities to temperature: some detect cold and some detect heat th cold receptors can also be activated by menthol and heat receptors can also be activated by capsaicin

110
Q

the pathway that the c fibers and A delta follow is…

A

the spinothalamic pathway

111
Q

in the spinothalamic pathway, axons…

A

synapse as soon as they enter the spinal column. then the second order neurons cross over to the contralateral side and ascend to the thalamus. the 3rd order neurons then go from the thalamus to the primary somatosensory cortex

112
Q

if someone has unilateral damage on the right side of their body on the spinal cord, what sensations would you expect to be lost?

A

the person would lose the ability to detect touch, vibration, 2 point discrimination and proprioception below the lesion on the right side/SAME SIDE of the body and they would lose the ability to detect pain and temperature on the left side/opposite side of the body below the lesion

113
Q

pain is reduced by…

A

the simulataneous activation of mechanoreceptors (ie rubbing your skin where it hurts reduces the pain. this happens because A alpha and A beta axons activate inhibitory interneurons that reduce the activity of the spinothalamic tract

114
Q

the descending pain control pathway controls…

A

how much pain goes into the brain

115
Q

stimulation of PAG in the midbrain produces pain relief by…

A

projecting to the dorsal horn of the spinal cord which then activates the inhibitory interneurons in the spinothalamaic tract. morphine works by binding to the opoid receptors in the PAG which lead to inhibitiion. natural endorphins also work this way

116
Q

lower motor neurons have their cell bodies in the…

A

ventral horn of the spinal cord. here they make synaptic contact with muscle fibers - Neuronmuscular junction! this is controlled by the upper motorneurons in the brain

117
Q

proprioceptors are sensory receptors that…

A

tell the brain about body position. they are associated with muscles and tendons

118
Q

proprioceptors are found in…

A

muscles spindles and golgi tendons

119
Q

intrafusal muscles fibers function to…

A

monitor muscle length

120
Q

intromuscle fibers are wrapped with …

A

Ia sensory axons. the axons are activated when the muscle is stretched and the mechanoreceptors in the axon are activated.

121
Q

the two different types of lower motorneurons are…

A

alpha motorneurons and gamma motor neurons

122
Q

alpha motorneurons synapse on…

A

extrafusal fibers

123
Q

gamma motorneurons synapse on…

A

intrafusal fibers within the muscle spindle

124
Q

both alpha and gamma motorneurons are activated at the same time because…

A

otherwise there would be no tension generated in the muscles and the brain would recieve no information about it

125
Q

both alpha and gamma motorneurons are located in…

A

the ventral horn of the spinal cord

126
Q

when alpha and gamma motorneurons are activated (mechanosentivie) and there is tension in the muscles,…

A

Ia sensory axon is then activated and it sends information to the brain

127
Q

the golgi tendon organ is located between the tendon and the muscle and it..

A

monitors muscle tension, associated with the IB sensory axon

128
Q

the two descending spinal tracts for motorneurons are…

A

the lateral and ventromedial

129
Q

the lateral descending spinal tract is composed of…

A

the corticospinal and rubrospinal tracts

130
Q

the lateral descending spinal tract is responsible for…

A

voluntary control of distal muscles

131
Q

the ventromedial pathway is composed of the…

A

tectospinal and vestibulospinal tracts

132
Q

the ventromedial pathway is responsible for…

A

controlling posture - central muscles!

133
Q

the rubrospinal tract is the one responsible for…

A

gross movements, no fine motor skills from this

134
Q

the corticoprinal tract is responsible for…

A

fine motor skills. can still move if this is damaged but you would have gross movements only

135
Q

teh basal ganglia does not…

A

send signals directly down the spinal cord

136
Q

the basal ganglia functions to…

A

initiate wanted movements and inhibit unwanted movements

137
Q

the diseases associated with the basal ganglia are…

A

PD, huntington’s and tourettes

138
Q

the frontal and sensory cortexes come together to provide…

A

info to the basal ganglion where the signals then go to the thalamus and then out to the motor cortex

139
Q

the globus pallidus of the basal ganglia has neurons that are…

A

spontaneously active which inhibits the thalamus

140
Q

to allow movement to take place, the globus pallidus must…

A

be turned off

141
Q

the glous palladius is turned off by activating…

A

the putaman

142
Q

the putaman is activated by…

A

the frontal cortex and teh substantial nigra

143
Q

in PD, neurons in the _____ dies which leads to less activation of the putaman and therefore less deactivation of teh basal ganglion so movement cannot happen

A

substantial nigra

144
Q

teh cerebellum functions in…

A

coordination of sequences of movements, storing motor memories, and in two way communication between the cerebellum and the motor cortex. also recieves sensory info and detects motor error (difference between intended motion and actual motion) reduces motor error since it can observe it

145
Q

the photoreceptors of the retina develop from…

A

the optic cups

146
Q

axons of ganglion cells make up the…

A

optic nerve

147
Q

the ganglion cells of the optic nerve…

A

fire action potential

148
Q

the bipolar cells and photoreceptors of the retina/eye…

A

have graded electrical responses

149
Q

the fovea is located at…

A

the very center of the retina

150
Q

bipolar cells and ganglion cells are bent away from the fovea so…

A

light has direct access to photorecptors which is why we can see most clearly at the fovea

151
Q

rods are ____ light sensitive than cones

A

more

152
Q

rods and cones differ from other nerve cells because…

A

they have outer segments composed of disks where the photopigments are stored

153
Q

the outer segment on rods is larger than the one on cones which means…

A

there is more photopigment and therefore are ~1000s times more light sensitive than cones

154
Q

rods are used for _____ vision

A

night

155
Q

since rods only have one type of photopigment…

A

at night time we cant see in color

156
Q

there are 3 different types of cones that differ in…

A

the type of photopigment that they have

157
Q

cones are in the ____ and rods are in the ___

A

fovea; periphery

158
Q

in the peripheral retina…

A

many rods converge onto one ganglion cell which is good for low light conditions but not for seeing details

159
Q

there is a 1:1 ration of cones to ganglion cells whcih is good for…

A

seeing details

160
Q

the process of converting light into an electrical signal is called…

A

phototransduction

161
Q

photoreceptors depolarize in dark conditions (become less negative) which causes…

A

neurotransmitters to be released in the dark, there is a Na+ current through the sodium channels

162
Q

photoreceptors polarize in the light (become more negative) which causes…

A

neurotransmitter to no longer be released

163
Q

the photopigment in rods is…

A

rhodopsin

164
Q

rhodopsin is composed of…

A

the protein opsin and retinal (a small molecule within opsin)

165
Q

retinal is made by…

A

vitamin A (poorer night vision when vit. A deficient)

166
Q

when light is detect in dark conditions, the photon energy is absorbed by the retina and then…

A

retinal chnages in conformation which then activates opsin

167
Q

when rhodopsin is activated by light, a G protein (transductin) is activated. this then…

A

activates phosphodiesterase which converts cGMP to GMP. GMP does not hold the Na+ channels open so they close and the cells become more negative since theres no influx of Na+

168
Q

there are three different opsins in cones:

A

red blue and green, they all absorb different wavelengths

169
Q

the two classes of bipolar cells are…

A

on and off

170
Q

off bipolar cells depolarize when…

A

light is off.

171
Q

on bipolar cells depolarize when…

A

light is on

172
Q

photoreceptors release the neurotransmitter glutamate and…

A

on/off bipolar cells both have different glutamate receptors which allows them to respond to light on and light off

173
Q

off bipolar cells have “normal” or AMPA glutamate receptors that…

A

bind when the light is off, causing the off bipolar cell to depolarize

174
Q

on bipolar cells have a G-protein cpupled glutamate receptor (mGluR6) and when….

A

glutamate binds here the cells hyperpolarize

175
Q

when on bipolar cells depolarize, on ganglion cells…

A

fire action potentials, same happens for off ones

176
Q

when the center of vision is dark, there is an…

A

increase in the rate of firing action potentials

177
Q

when both the center and the surroundings are dark,

A

there is an antagonistic response because one makes action potentials increase and the other makes them decrease

178
Q

there are also m and p types of…

A

on/off ganglion cells

179
Q

m type on/off ganglion cells…

A

cover a larger area of the retina and have a transient burst of action potentails they also detect motion

180
Q

p type on/off ganglion cells have a…

A

smaller receptive field, sustained action firing potential and detect shapes of objects

CNB (2 decks)

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