Chapter 2 part 3 Flashcards

nerve cells and their messages

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1
Q

how is the neuron different from other cells in the body?

A

it is specialized for communication

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2
Q

what is a neuron?

A

a specialized cell of the nervous system

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3
Q

what is a neuron used for?

A

detecting information, transmitting information, and affecting muscles and glands

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4
Q

what is the soma of the neuron?

A

the round part that contains everything a regular human cell would (nucleus, mitochondria, etc.)

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5
Q

what is the name for the cell body of the neuron?

A

the soma

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6
Q

what do dendrites look like?

A

tree branches at the beginning of the neuron

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7
Q

what does the axon look like?

A

the long tube in the middle of the neuron

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8
Q

what do terminal buttons look like?

A

the little balls at the end of the neuron

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9
Q

what do dendrites do?

A

receive messages from neighboring neurons or the outside world

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10
Q

if a dendrite receives a message from a neuron, what does it usually consist of?

A

neurotransmitters (chemicals)

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11
Q

in what situation is there more dendrites than normal?

A

in a part of the brain where no chemical messages can be missed

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12
Q

in what situation is there less dendrites than normal?

A

in a part of the brain that doesn’t receive many messages

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13
Q

what happens to the neurons in a part of the brain that is being used more often

A

they can grow new spines

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14
Q

use it or lose it

A

use the pathway and grow neurons or don’t and the brain gets rid of the pathway and sometimes the neurons (like pruning trees, we need to prune the smaller branches so the big healthy ones can keep growing)

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15
Q

axon

A

conducts nerve impulse from the cell body to distant location -> carries the electrical impulse

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16
Q

myelin sheath

A

increases speed and efficiency of nerve impulse

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17
Q

how do axons look?

A

they can be short or as long as your body, some are wide tubes and others are skinny

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18
Q

what does myelin sheath look like?

A

pellet covering that wraps around sections of axon, looks white

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19
Q

what is myelin sheath made out of?

A

lipids (fat)

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20
Q

how does myelin sheath increase speed and efficiency?

A

it wraps around sections of the axon to insulate it and protect the axon from interference (like the plastic covering on a wire)

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21
Q

terminal buttons

A

release chemical messages (neurotransmitters) onto neighboring dendrites

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22
Q

when are neurons active?

A

all the time

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23
Q

electrochemical transmission

A

communication from nerve cell to nerve cell

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24
Q

how does a neuron generate electricity?

A

using charged particles called ions

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25
Q

what is cerebral spinal fluid?

A

the liquid our brains float it, it has ions and tastes salty

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26
Q

where do electrical signals ALWAYS start?

A

the cell body

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27
Q

where do electrical signals ALWAYS end?

A

terminal buttons

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28
Q

the inside of a neuron is more _________ than cerebral spinal fluid

A

negatively charged

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29
Q

the cerebral spinal fluid is more ________ than the inside of a neuron

A

positively charged

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30
Q

iNside

A

negative

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31
Q

outside

A

positive

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32
Q

what happens when the axon membrane won’t let sodium (Na) in?

A

Na lines up on the outside of the membrane

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33
Q

why does Na want in the axon?

A

because the inside of the neuron is more negatively charged than the cerebral spinal fluid, and Na is a positive ion

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34
Q

what is already inside the axon when it is at rest?

A

potassium (K)

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35
Q

what are the holes in the membrane for?

A

they sometimes allow ions to go in and out of the axon

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36
Q

when are the channels closed?

A

when the neuron is at rest and the inside is more negative than the outside

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37
Q

membrane potential

A

difference in charge (voltage) across a cell membrane

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38
Q

resting membrane potential

A

-70 millivolts (more negative than outside the membrane)

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39
Q

threshold

A

minimum amount of stimulation necessary to open channels and trigger the neural impulse

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40
Q

after stimulation and a channel opens ->

A

sodium (Na) rushes in the cell and potassium (K) is also positive so it rushes out, this is enough stimulation to open the next channel (and so on for all the other channels in the membrane)

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41
Q

what really is the electrical signal?

A

the exchange of Na and K along the axon

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42
Q

action potential

A

brief wave of positive electrical charge that sweeps down the axon

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43
Q

action potential is defined by what?

A

sodium

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44
Q

during the refractory period, the inside of the cell is __________

A

more negative than when it is at rest for a short period of time (milliseconds)

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45
Q

refractory period

A

after a neuron fires, there is a period of time where it cannot fire again

46
Q

what happens during the refractory period?

A

pumps in the membrane work to pump K in and Na out to bring the neuron back to resting potential (basically resetting the neuron)

47
Q

can a neuron fire during the refractory period?

A

no

48
Q

all-or-none law

A

if threshold is reached, a full action potential occurs. if threshold is not attained, then no action potential will occur

49
Q

what is the basic definition of the all-or-none law?

A

a neuron either fires or doesn’t fire. like a gun, it can’t half go off, it can only go off or not

50
Q

when a neuron is fired, is it fired exactly the same everytime?

A

yes, because it can only fire or not

51
Q

do neurons typically touch?

A

no, there is always a gap between them

52
Q

synapse

A

the gap between neurons

53
Q

are terminal buttons specialized?

A

yes, they only can squirt out one type of neurotransmitter

54
Q

what happens when the action potential reaches the end of the axon?

A

it triggers a reaction in the terminal buttons that makes them squirt out neurotransmitters into the synapse

55
Q

synaptic vesicles

A

store neurotransmitters in sacs (package them in bags)

56
Q

where are receptors located?

A

on the dendrites

57
Q

neurotransmitters

A

chemical messages

58
Q

what do receptors do?

A

receive neurotransmitters

59
Q

can a neurotransmitter open more than one receptor?

A

yes, because they are reusable

60
Q

does every neurotransmitter have a different shaped molecule?

A

yes, and their receptors are shaped specifically for them (like locks and keys)

61
Q

can a dopamine molecule go in a serotonin receptor?

A

no, because they aren’t the same shape (the key doesn’t fit into the lock)

62
Q

chain reaction process

A

dendrites –> cell body –> axon –> terminal buttons –> neurotransmitter release –> dendrites –> cell body –> axon –> etc.

63
Q

excitatory synapse

A

when neuron A releases neurotransmitters onto neuron B, neuron B will be more likely to fire

64
Q

inhibitory synapse

A

when neuron A releases neurotransmitters onto neuron B, neuron B will stop firing or is less likely to fire

65
Q

what happens when neurons fire out of control?

A

a seizure, this is why we need inhibitory and excitatory synapses

66
Q

how do we eliminate the neurotransmitter from the synapse after is has done its job?

A

enzymatic degradation and reuptake

67
Q

enzymatic degradation

A

enzymes in cerebral spinal fluid that destroy neurotransmitters. every neurotransmitter has a specific enzyme that destroys it

68
Q

reuptake

A

neurotransmitters are pulled back into terminal buttons and get repackaged and reused (like putting your key in back in your pocket and pulling it out the next time you need it)

69
Q

endogenous

A

made inside your body

70
Q

exogenous

A

made outside of your body from plants in labs to mimic endogenous chemicals

71
Q

7 most popular neurotransmitters

A

acetylcholine, dopamine, serotonin, norepinephrine, glutamate, GABA, endorphins

72
Q

very 1st neurochemical ever discovered

A

acetylcholine

73
Q

acetylcholine

A

involved in movement, learning, and memory

74
Q

MUST have to move any muscle in your body

A

acetylcholine

75
Q

how snake and spider venoms paralyze prey

A

they block acetylcholine

76
Q

how does botox work?

A

it blocks acetylcholine in injection areas so you can’t move the muscles and create wrinkles

77
Q

abbreviation for acetylcholine

A

ACh

78
Q

dopamine

A

involved in movement, attention, short-term memory, planning, and reward

79
Q

how does Parkinson’s work?

A

it is a disruption in dopamine pathways that won’t let sufferers from the disease move

80
Q

what happens when you get a squirt of dopamine

A

you feel compelled to do that behavior again

81
Q

when do we get a squirt of dopamine?

A

when we do something good for our species (eating, drinking, sex, etc.)

82
Q

how does dopamine create a pathway to addiction

A

when we do specific drugs, we get a hit of dopamine and we feel compelled to use those drugs again

83
Q

abbreviation for dopamine

A

DA

84
Q

what does cocaine do to our brains involving neurotransmitters

A

it makes more dopamine available than our brains are used to

85
Q

why is meth so addictive?

A

because it makes more dopamine available than any other drug

86
Q

serotonin

A

involved in sleep, mood, and eating

87
Q

abbreviation for serotonin

A

5-HT

88
Q

how do antidepressants work?

A

they block reuptake so serotonin stays in the synapse longer so it can open more locks –> enhances the serotonin level in the synapse

89
Q

how does MDMA (ecstasy) work?

A

it enhances serotonin and elevates mood

90
Q

why is MDMA (ecstasy) not used as an antidepressant?

A

it can kill neurons

91
Q

norepinephrine

A

involved in attention and arousal

92
Q

epinephrine

A

adrenalin and is only in peripheral nervous system)

93
Q

abbreviation for norepinephrine

A

NE

94
Q

what does norepinephrine do?

A

when we are scared / excited, the brain releases NE and we become more vigilant (similar to adrenalin)

95
Q

when do we have the base level of NE?

A

when we are awake

96
Q

when do we have lower levels of norepinephrine?

A

when we are asleep

97
Q

what neurotransmitters are also amino acids?

A

glutamate and GABA

98
Q

glutamate

A

primary excitatory neurotransmitter

99
Q

what happens when glutamate is released?

A

neurons start firing

100
Q

what happens when glutamate is released in the amygdala?

A

we feel very anxious

101
Q

GABA

A

primary inhibitory neurotransmitter

102
Q

there is more of these two neurotransmitters than any other in the brain

A

GABA and glutamate

103
Q

what happens when GABA is released?

A

neurons go silent

104
Q

what happens when GABA is released in the amygdala?

A

we become very relaxed

105
Q

anxiety meds (benzos) enhance which neurotransmitter?

A

GABA

106
Q

we take drugs that enhance ________ and inhibit _________

A

GABA ; glutamate

107
Q

endorphins

A

involved in pain inhibition and pleasure

108
Q

endogenous opiods

A

modulates pain

109
Q

do endorphins enhance or inhibit pain?

A

inhibit

110
Q

why are endorphin drugs so addictive?

A

they open pathways to dopamine, which then compels us to continue the behavior

111
Q

how do opiates (narcotics) work?

A

they mimic endorphins for when we’re in pain by inhibiting pain and the medulla

112
Q

does our brain constantly release endorphins?

A

yes, because we experience everyday wear and tear