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Be it, feel it > Item 4 > Flashcards

Item 4 Flashcards

1
Q

Long-distance communication is a function of the _ system and the nervous system

A

endocrine

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2
Q

The _ nervous system (_NS) consists of the brain and spinal cord

A

central

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3
Q

_ information is received and processed by _ory organs and the viscera to determine the state of the external environment

A

sensory information; sensory organs

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4
Q

The internal environment is considered _ information of the CNS

A

VISCERAL

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5
Q

The _ integrates sensory and visceral information to make decisions on appropriate actions then sends instructions to certain organs instructing them to perform appropriate tasks

A

CNS

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6
Q

The _NS is also the site of:
learning
_
emotions
thoughts
language
other complex functions

A

memory

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7
Q

The _NS consists of neurons that provide communication between the _NS [different!] and organs throughout the body

A

PNS; CNS

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8
Q

The PNS can be subdivided into two divisions:
_erent
_erent

A

afferent; efferent

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9
Q

Neurons of the _erent division transmit sensory and visceral info from the organs to the CNS

A

afferent

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10
Q

Info transmitted to the CNS includes the _ senses, associated with the skin, muscles and joints

A

somatic senses

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11
Q

Info transmitted to the CNS includes the _ senses, associated with vision, hearing, equilibrium, smell, taste)

A

special senses

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12
Q

Info transmitted to the CNS includes visceral information associated with the internal environment such as:
fullness of the stomach
blood pressure
…

A

blood pH

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13
Q

Neurons of the _erent division transmit information from the CNS to organs in the periphery

A

efferent

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14
Q

Neurons of the efferent division transmit information from the CNS to organs in the periphery, called _ organs

A

effector

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15
Q

_ organs perform functions in response to commands from neurons

A

effector

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16
Q

Effector organs perform functions in response to commands from neurons; they’re usually muscles and _

A

glands

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17
Q

A neuron capable of transmitting messages to an effector organ or receiving info from a sensory organ is said to _ate that organ

A

innervate

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18
Q

The efferent division can be subdivided into two main branches:
the somatic/voluntary NS and
_/involuntary NS

A

autonomic/involuntary NS

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19
Q

The efferent division can be subdivided into two main branches:
the _/voluntary NS and
autonomic/involuntary NS

A

somatic/voluntary NS

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20
Q

The somatic NS consists of the _ _ns, which regulate skeletal muscle contractions

A

motor neurons

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21
Q

The _ _ _ consists of neurons that regulate the function of internal organs and other structures

A

autonomic NS

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22
Q

The Autonomic NS consists of neurons that regulate the function of internal organs and other structures, such as sweat glands and _ _, that are not under voluntary control

A

blood vessels

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23
Q

The autonomic nervous system can be divided into two branches:
the _etic NS
the _etic NS

A

parasympathetic NS and sympathetic NS

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24
Q

The _ NS comprises of an intricate network of neurons in the gastrointestinal tract that can function independently of the rest of the nervous system but communicates with the autonomic NS

A

ENTERIC nervous system

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25
Q

The NS contains two main classes of cells:
neurons
_ _

A

glial cells

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26
Q

The neuron is the _ _, the smallest unit of a tissue that can carry out the tissue’s reason for existing

A

functional unit

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27
Q

Neurons are _ cells, capable of producing large, rapid electrical signals

A

excitable

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28
Q

Neurons are excitable cells, capable of producing large, rapid electrical signals called _ _

A

action potentials

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29
Q

Glial cells, which account for _% of the cells in the NS, provide various types of support to the neurons, including structural and metabolic support

A

90%

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30
Q

Neural processes or _ extend from the cell body

A

neurites

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31
Q

Two types of neurites extend from the cell body:
dendrites
_

A

axons

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32
Q

The cell body or _ contains the cell nucleus, endoplasmic reticulum, Golgi apparatus, and most of the free ribosomes

A

soma

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33
Q

_ are located in the cell body, but also throughout the body

A

mitochondria

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34
Q

The cell body carriers out most of the functions that other cells perform, such as protein synthesis and cellular _

A

metabolism

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35
Q

T or F: mature neurons do not retain their nuclei, but they keep their ability to undergo cell division

A

FALSE! mature neurons retain their nuclei, but lose their ability to undergo cell division

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36
Q

T OR F: adults have all the neurons they will ever have

A

true

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37
Q

Can new neurons develop from undifferentiated cells in the adult human brain?

A

yes

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38
Q

Undifferentiated cells or _ cells can develop in a few areas of the adult human brain

A

stem cells

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39
Q

_ branch from the cell body and receive input from other neurons at specialized junctions

A

dendrites

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40
Q

Dendrites branch from the cell body and receive input from other neurons at specialized junctions called _

A

synapses

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41
Q

T OR F: cell bodies themselves can receive input at synapses

A

true

cell bodies can receive input at synapses as well as dendrites that branch from the cell body

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42
Q

_ cells are star-shaped

A

stellate

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43
Q

The extent of _ is an indication of the number of synapses with the neuron, as the majority of synapses occur there

A

branching (i.e., dendrites)

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44
Q

The nerve fibre, or _, serves to send information (unlike a dendrite which receives information)

A

axon

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45
Q

T OR F: neurons can have several axons

A

false
generally they only have one, but axons can branch, sending signals to more than one destination

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46
Q

The branches of an axon are called _; the extent of branching varies among neurons and is indicative of the amount of communication with other cells

A

collaterals

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47
Q

The axon function in rapid…over relatively long distances in the form of electrical signals

A

rapid transmission of information

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48
Q

The axon function in the rapid transmission of information over relatively long distances in the form of electrical signals, i.e., _ _

A

action potentials

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49
Q

Action potentials are brief, large changes in membrane potential during which the _ of the cell becomes positively charged relative to the _

A

inside of the cell becomes positively charged relative to the outside
i.e., positive membrane potential due to action potentials

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50
Q

T OR F: the beginning of an axon are specialized structures called the axon terminal and the end is the axon hillock

A

false - axon hillock is the beginning, axon terminal is the end of an axon

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51
Q

T or F: the axon hillock is specialized in most neurons for the initiation of action potentials

A

true

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52
Q

the _ _ is specialized to release neurotransmitter on arrival of an action potential

A

axon terminal

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53
Q

The axon is specialized to release neurotransmitter on arrival of an action potential. The released neurotransmitter molecules carry a signal to a _ cell

A

postsynaptic cell

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54
Q

T OR F: a released neurotransmitter molecule carries a signal to a dendrite or the cell body of another neuron or to the cells of an effector organ

A

true

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55
Q

_c cells are in charge of releasing neurotransmitter from their neuron’s axon terminal

A

presynaptic cells

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56
Q

Axons range in length from 1 _ to 1 m

A

1 mm

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57
Q

In order for an axon terminal to carry out its function, it must have:
_ for synthesizing neurotransmitters
transporter molecules to move NTs
substrates across membranes
vesicles to store NTs until an action potential triggers exocytosis

A

enzymes for synthesizing NTs

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58
Q

Vesicles store NTs until an action potential triggers _

A

exocytosis

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59
Q

_ _n is too slow to complete the process of transport from cell body to axon terminal

A

simple diffusion

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60
Q

Simple diffusion is too slow to complete the process of transport from cell body to axon terminal, therefore special transport mechanisms exist for _ transport

A

axonal transport

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61
Q

Neurons move products from the cell body to axon terminal, a.k.a. _e transport

A

anterograde

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62
Q

Neurons move products from the axon terminal to the cell body using _e transport

A

retrograde

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63
Q

_ axonal transport and _ axonal transport are both used for anterograde and retrograde transport.

A

Fast axonal transport and slow axonal transport

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64
Q

T or F: only fast axonal transport involves proteins, including microtubules and a variety of neurofilaments

A

false - both fast and slow axonal transport involves proteins

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65
Q

Slow axonal transport (0.5 - _ mm/day) is generally associated with movement of small soluble molecules in the cytosol

A

0.5 - 44 mm/day (up to the length of a fingernail)

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66
Q

Fast axonal transport (100 - _ mm/day) is associated with movement of vesicles, including synaptic vesicles

A

400 mm/day (up to the length of a hand?)

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67
Q

Fast axonal transport of vesicles uses _ to extend the length of the axon and function as “tracks” for transport molecules

A

microtubules

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68
Q

Proteins that essentially “walk” down the microtubules, carrying a vesicle with them, run on tracks called _

A

kinesins

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69
Q

Fast axonal transport of vesicles requires _ for energy

A

ATP

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70
Q

Most ion channels are _ because different regions of a neuron generally have specialized functions

A

gated channels

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71
Q

The opening or closing of ion channels changes the … for a specific ion, resulting in a change in the electrical properties of the cell or the release of a NT

A

permeability of the plasma membrane

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72
Q

Nongated channels or _ channels are found in the plasma membrane

A

leak channels

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73
Q

Nongated channels or leak channels are found in the plasma membrane, and are responsible for the _ membrane potential

A

resting membrane potential

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74
Q

- channels open or close in response to the binding of a chemical to a specific receptor in the plasma membrane

A

ligand-gated

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75
Q

In neurons, ligand-gated channels are most densely located in the _ and cell body - areas that receive communication from presynaptic neurons in the form of NTs

A

dendrites

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76
Q

- channels open or close in response to changes in membrane potential

A

voltage-gated

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77
Q

_-gated potassium and -gated sodium channels are located throughout the neuron, but are more densely clustered in the axon and are present in greatest density in the axon hillock

A

Voltage-gated sodium and voltage-gated potassium channels

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78
Q

When voltage-gated _ channels are open, _ enters the cytosol of the axon terminals and triggers the release of NT

A

voltage-gated calcium channels; calcium

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79
Q

Neurons can be classified structurally according to the number of _ that project from the cell body

A

processes (i.e., axons and dendrites)

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80
Q

_ neurons are generally sensory neurons with two projects: an axon and a dendrite coming off the cell body

A

bipolar

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81
Q

the two senses that use bipolar neurons are _ and vision

A

smell / olfaction

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82
Q

Pseudo-unipolar neurons are named as such because the _ is modified to function much like an axon, and is a functional continuation of the axon

A

dendrite

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83
Q

Pseudo-unipolar neurons are named as such because the dendrite is modified to function much like an axon, and is a functional continuation of the axon. This modified dendritic process is called the _ axon, because it originals in the exterior with sensory receptors and functions as an axon in that it transmits action potentials

A

peripheral axon

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84
Q

_r neurons are the most common neurons

A

multipolar neurons

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85
Q

The cell body and dendrites of efferent neurons are located in the CNS, except for the _ic _ic neurons

A

autonomic postganglionic neurons

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86
Q

The axon leaves the CNS and becomes part of the _ NS as it travels to the effector organ it innervates

A

peripheral / PNS

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87
Q

Most _t neurons are pseudo-unipolar neurons, with the cell body located outside the CNS in a ganglion

A

afferent neurons

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88
Q

_neurons account for 99% of all neurons in the body

A

interneurons

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89
Q

Interneurons account for 99% of all neurons in the body, entirely in the _NS

A

central nervous system

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90
Q

Interneurons perform all the functions of the CNS, including:
processing sensory info from afferent neurons
creating and sending out commands to effector organs through efferent neurons
and carrying out…

A

complex functions of the brain such as thought, memory and emotions

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91
Q

Cell bodies of neurons are often grouped into _

A

nuclei

92
Q

Axons travel together in bundles called _ways, _ts, or _ures

A

pathways, tracts, or commissures

93
Q

In the PNS, cell bodies of neurons are clustered together in _, and the axons travel together in bundles/nerves

A

ganglia

94
Q

Glial cells’ main functions include:
providing structural integrity to the NS
chemical and anatomical support that permits…

A

neurons to carry out their functions

95
Q

There are four types of glial cells:
astrocytes
microglia
_
Schwann cells

A

oligodendrocytes

96
Q

T OR F: of glial cells, only oligodendrocytes are located in the PNS

A

FALSE - only Schwann cells are found in the PNS

97
Q

Neurolemmocytes are another name for _ cells

A

Schwann, found in the PNS

98
Q

The primary function of oligodendrocytes (CNS) and Schwann cells (PNS) is to form…

A

myelin around the axons of neurons

99
Q

Myelin provides insulation that enables neurons to … more efficiently and rapidly

A

transmit action potentials

100
Q

Myelin consists of _ layers of the plasma membranes of either oligodendrocytes or Schwann cells

A

concentric

101
Q

T OR F: Oligodendrocytes send out projections providing the myelin segment for one axon each, whereas Schwann cells form myelin provides for several axons each

A

false - oligodendrocytes provide for many axons, whereas Schwann cells provide myelin for one axon each

102
Q

T or F: many oligodendrocytes or Schwann cells are needed to provide the myelin for a single axon

A

true

103
Q

The lipid bilayer of a plasma membrane has _ permeability to ions, the several layers of membrane that make up a myelin sheath substantially _ leakage of ions across the cell membrane

A

low permeability = less leakage/chance of the suckers getting out; reduces leakage

104
Q

_ of _ are the gaps within myelin

A

Nodes of Ranvier

105
Q

The axonal membrane that contains voltage-gated sodium and potassium channels that function in the transmission of action potentials by allowing ion movement across the membrane are due to the gaps within the myelin, known as _ _ _

A

Nodes of Ranvier

106
Q

All cells in the body have a negative resting membrane potential, ranging from -5 mV to -_mV

A

-100!

107
Q

The chemical forces for moving Na and K ions across the plasma membrane and the differences in the permeability of the plasma membrane to these ions, establish the _ _ _

A

resting membrane potential

108
Q

Sodium ions are at a higher concentration _ the cell and are balanced electrically by the presence of chloride ions outside the cell

A

outside the cell

109
Q

_ ions are at a higher concentration inside the cell and are balanced electrically by the presence of organic anions, primarily proteins, inside the cell

A

potassium ions

110
Q

As potassium ions move, they carry their positive charge _ the cell, which leaves the _ [opposite] of the cell negatively charged relative to the _ [first answer], creating a negative membrane potential

A

outside the cell
inside
outside

111
Q

Currents are typically expressed in units of _ (10 ^ -6 amperes)

A

microamps

112
Q

The greater the electrical potential, the greater the _ for ion movement

A

force

113
Q

T OR F: the presence of a force necessitates ion movement

A

false - it can depend on resistance or conductance (its opposite)

114
Q

The ICF and ECF have high resistance to current flow because their fluids are rich in ions. T or F?

A

false - the ICF and ECF have LOW resistance to current flow

115
Q

(R) is a measurement of the hindance to charge movement

A

resistance

116
Q

(g) is the ability of an ion to cross a plasma membrane depending on the permeability of the plasma membrane to that ion

A

conductance

117
Q

_’s law suggests that the conductance of a particular ion increases as the membrane’s permeability to that ion increases:

l = E / R

A

Ohm’s law

118
Q

Cells permeable to potassium only would see K+ move out of the cell because of a _ force

A

chemical force

119
Q

Cells permeable to potassium only would see K+ move out of the cell because of a chemical force. As some leave the cell, the inside of the cell becomes _ charged relative to the outside, creating an electrical force that moves potassium ions into the cell, opposing the chemical force

A

negatively charged

120
Q

Cells permeable to potassium only would see K+ move out of the cell. Eventually enough potassium leaves the cell that the electrical force becomes strong enough to oppose further movement of K+ ions out of the cell because of chemical force, resulting in…

A

no net movement of potassium ions

121
Q

Cells permeable to K+ cells only have a potassium equilibrium potential of approximately -_mV in neurons

A

-94 mV

122
Q

At potassium equilibrium potential, the electrical force exactly opposes chemical force, meaning…

A

no potassium moves

123
Q

Ek refers to…

A

equilibrium potential for potassium

124
Q

Ex refers to equilibrium potential of…

A

any ion (i.e., x = anything)

125
Q

For a cell permeable only to Na+, the electrical force tends to take sodium… because of the repulsion between the positively charged sodium ions and the net positive charge inside the cell

A

out of the cell

126
Q

The number of open _ channels far exceeds the number of open _ channels for ion gradients across the cell membrane

A

more open potassium channels to open sodium channels

127
Q

T or F: sodium and potassium come to equilibrium because the movement of each opposed the other

A

false - sodium and potassium CANNOT come to equilibrium because the movement of each opposes the other

128
Q

The resting membrane potential is actually much closer to the potassium equilibrium potential than the sodium one because…

A

the cell is more permeable to potassium, i.e., more potassium leaves the cell than sodium enters

NOTE: this differs from action potentials, with 3 Na+ released to 2 K+ entering the cell. Perhaps a way to balance out the permeability

129
Q

If a neuron had equal permeability to sodium and potassium ions, would the resting membrane potential of that cell be more negative or less negative than -70 mV?

A

the membrane potential would be less negative (more depolarized), to balance the more reduced concentration of positive K+ ions

130
Q

The sodium-potassium pump establishes the concentration gradients and maintains them. T or F?

A

true

131
Q

Because the sodium-potassium pump is _ - it transports a net positive charge out of the cell - it contributes directly to the resting membrane potential, despite a minimal effect that accounts for only a few millivolts of charge separation

A

electrogenic

132
Q

Because energy is required to sustain the resting state of a neuron, the cell is not at equilibrium; rather, it is in a _ _

A

steady state

133
Q

The membrane potential depends on the _ _ of the membrane to the different ions that exist on either side

A

relative permeabilities of the membrane to different ions

134
Q

As the membrane’s permeability to a particular ion increases, the membrane potential moves _ to that ion’s equilibrium potential

A

closer

135
Q

Can the Nernst equation be used to calculate the membrane potential of an ion?

A

no, just the EQUILIBRIUM potential for a specific ion - we use the GHK equation instead

136
Q

The GHK equation, or --_ equation, the membrane potential can be approximated for situations in which only sodium and potassium are permeant

A

Goldman-Hodgkin-Katz equation

137
Q

“o” and “i” respectively refer to the _ outside and inside the cell for the GHK equation

A

concentration outside and inside the cell, respectively

138
Q

“P Na” and “P K” are the _’s _ to sodium and potassium, respectively, in the GHK equation

A

membrane’s permeability for sodium and potassium

139
Q

By dividing the GHK equation’s numerator and denominator both by “P K”, we can calculate the membrane potential in _

A

millivolts

140
Q

If the permeability to either sodium or potassium is equal to zero (i.e., equilibrium potential for the ion that is not zero), then the GHK equation becomes…

A

the Nernst equation for the other ion

141
Q

If the membrane is permeable to only one ion, then the membrane potential is…

A

equal to the equilibrium potential of that ion

142
Q

The net electrochemical force on an ion tends to move that ion across the membrane in the direction that…

A

will move the membrane potential toward that ion’s equilibrium potential

143
Q

If sodium is 130 mV away from equilibrium (at a resting membrane potential of -70) whereas potassium is only 24 mV away from equilibrium, the electrochemical force moving sodium into the cell is _ than the electrochemical force moving potassium out of the cell

A

greater
- the further away from an ion’s equilibrium potential, the greater the electrochemical force working against it

144
Q

I Na = g Na (Vm - E Na) is…

A

the sodium current

145
Q

I Na = g Na (Vm - E Na) shows…
I = current of a specific ion
g equals the _ of that ion (directly related to permeability)
E equals equilibrium potential of that ion and
Vm equals membrane potential

A

g equals the conductance of that ion (opposite of resistance to flow)

146
Q

The channels responsible for the resting membrane potential are _ channels

A

leak

147
Q

T OR F: neurons have gated ions and leak channels

A

true

148
Q

If sodium ion channels open, then sodium movement _ the cell increases, driving the membrane potential toward the sodium equilibrium potential

A

INTO the cell

149
Q

Many toxins exert their poisonous effects by interfering with the actions of _ _

A

ion channels

150
Q

Hyperpolarization moves the mV to _ than -70 mV

A

LOWER - becomes -80, -90, etc., i.e., more polarized

151
Q

_ moves the mV to higher than -70 mV, i.e., -60, 0, etc.

A

depolarization, i.e., less polarized

152
Q

Repolarization moves the mV…

A

back to its resting potential, i.e., to below zero and eventually to -70 mV

153
Q

Tetrodotoxin, a neurotoxin from blowfish, attacks nervous system function by blocking - _ channels necessary for producing an action potential

A

voltage-gated sodium channels

154
Q

_ potentials are small electrical signals that act over short ranges because they diminish in size with distance

A

graded potentials

155
Q

T or F: action potentials are large signals capable of traveling long distances without decreasing in size

A

true

156
Q

Stimuli that produce graded potentials are:
chemical stimuli and
_ stimuli

A

sensory stimuli, such as a touch or light

157
Q

Chemical stimuli that produces graded potentials for neurotransmitters includes the …on a dendrite or the cell body of a neuron

A

BINDING TO RECEPTORS on a dendrite or the cell body of a neuron

158
Q

Sensory receptors at the peripheral ending of an _ neuron provide stimuli that produces graded potentials

A

afferent

159
Q

The _ of the change in membrane potential varies with according to the strength of the stimulus

A

magnitude

160
Q

The spread of voltage by passive charge movement is called _ conduction

A

electrotonic conduction

161
Q

As the graded potential spreads from the site of the stimulation, the current is spread over a larger area, and some current leaks across the plasma membrane. As a result, the size of the membrane potential change _ as it moves from the site of initial stimulation

A

decreases

162
Q

T or F: graded potentials are only depolarizations

A

false - they can be de- or hyper-polarizations

163
Q

Graded potentials determine whether a cell…

A

will generate an action potential

164
Q

If one type of neurotransmitter binding to its receptors caused sodium channels to open, then sodium ions would move _ the cell and the resulting graded potential would be a depolarization

A

INTO THE CELL

165
Q

If another type of neurotransmitter binding to its receptors caused potassium channels to open, then potassium ions would move _ of the cell, and the resulting graded potential would be a hyperpolarization

A

OUT OF THE CELL

166
Q

A _ is a critical value of membrane potential that must be exceeded if an action potential is to be generated

A

threshold

167
Q

Graded potentials that are depolarizations are described as _tory, whereas graded potentials that are hyperpolarizations are considered _tory

A

depolarizations are excitatory (they go up - less polar) whereas hyperpolarizations are inhibitory (they go down - more polar)

168
Q

Inhibitory graded potentials take the membrane potential … the threshold to elicit an action potential

A

away from the threshold

169
Q

Excitatory graded potentials take the membrane potential … the threshold to elicit an action potential

A

closer to the threshold

170
Q

T or F: a single graded potential is generally not of sufficient strength to elicit an action potential

A

true

171
Q

T or F: temporal summation is the overlap in time of action potentials that can sum, both temporally and spatially

A

false - it is the overlap in time of GRADED potentials

172
Q

_ summation is defined as the effects of stimuli from different sources occurring close together in time summation

A

spatial summation

173
Q

In spatial summation, a hyperpolarizing graded potential and a depolarization graded potential tend to…

A

cancel each other out

174
Q

A _ of charge is said to exist across the membrane, enabling potential energy to exist

A

separation

175
Q

Cations are attracted by the _ charge inside the cell and have an inward-directed electrical driving force

A

negative charge inside the cell

176
Q

If potassium moved into the cell, it would bring its positive charge with it, thereby making the membrane _ negative and taking potassium further from equilibrium

A

less negative (Ek = -94 mV)

177
Q

The _ driving force for an uncharged solute to move into a cell is determined by the …equation

A

van’t Hoff equation

178
Q

‘triangle’ G = RT ln [S]i / [S]o is the …equation

A

van’t Hoff equation

179
Q

[S]o in the van’t Hoff equation is the _ of solute S outside the cell, and [S]I is the _ of solute S inside the cell

A

concentration

180
Q

‘triangle G’ = RT ln [l]i / [l]o + zFE is the van’t Hoff equation for determining the _ driving force for an ion (l) to move INTO the cell

A

electrochemical driving force for an ion

181
Q

‘triangle G’ = RT ln [l]i / [l]o + zFE is the van’t Hoff equation for determining the electrochemical driving force for an ion (l) to move into the cell

G = …
R = universal gas constant (0.082 litrre-atm/mole-K)
T = absolute temperature (K)
z = valence of the ion
E is the membrane potential
F is Faraday’s constant for electrical forces (9.65 x 10^4 joules/volt-mole)

A

G = free energy

182
Q

The Nernst equation gives the value of the equilibrium potential in millivolts and assumes that the temperature is at or near …

A

body temperature, i.e., 37 degrees Celsius

183
Q

The sign (direction) of the equilibrium potential depends solely on the direction of the…

A

concentration gradient

this is noticeable in the Nernst equation, with a valence of +1 meaning it is a larger concentration gradient and requires a larger membrane potential to balance it (most commonly, K+ gradient larger than Na+)

184
Q

A valence of +1 in the Nernst equation means that it is a _ concentration gradient and requires a _ membrane potential to balance it

A

larger concentration gradient, and requires a larger membrane potential to balance it
e.g., (most commonly, K+ gradient larger than Na+)

185
Q

If concentration gradients are equal, then the equilibrium potential is…

A

zero
ie., Co / Ci = 1, making the equilibrium potential (log of 1) zero

186
Q

When ions are transported passively, they move _ their electrochemical gradient

A

down

187
Q

Are both actions of ion movement for the sodium-potassium pump active?

A

yes, they both move up their electrochemical gradient

188
Q

Each neuron can access upwards of _ synapses

A

10

189
Q

The PNS is not protected by skull or the vertebrae. T or F?

A

T

190
Q

Brain damage is more often the result of _NS damage since it is less protected than the CNS

A

pNS DAMAGE, rather than CNS damage

191
Q

The synaptic cleft is about _ um long

A

200

192
Q

Myelinated structures look _, therefore are called _ matter

A

white; white

193
Q

Grey matter is particular to collection of nerve cell _

A

bodies

194
Q

The cell body works as a _tor

A

capacitor (a great insulator)

195
Q

A piece of biological tissue is a good conductor of electricity. T or F?

A

false - imagine Homer’s image fading, whereas copper wires are great conductors, maximizing conduction

196
Q

Myelination is considered increasing _ _

A

increasing membrane resistance

197
Q

Oligodendrocytes look like _

A

octopi, myelinating multiple CNS axons

198
Q

There are roughly _ to _ layers of myelin, maximizing conduction velocity and reducing signal loss

A

50 to 100 layers per neuron

199
Q

The exposure of the Node of Ranvier is where the …

A

action potential is generating along the axon

200
Q

The speed of axon generation is from _ to _ m/s

A

2 vs 80 m/s

201
Q

Damage of the myelin sheath is specific to patients with _ _, leading to slowing down or even blockage between one’s brain and their body. (brain and spinal cord)

A

multiple sclerosis

202
Q

Symptoms of MS are:
visual disturbances
muscle weakness
trouble with coordination, balance
_
thinking and memory problems

A

sensations with prickling, numbness, pins and needles

203
Q

How is MS treated?

A

by reducing leakage occurrence by blocking calcium channels

204
Q

_ are the ligand for ligand-gated channels, largely found by the dendrites

A

neurotransmitters

205
Q

Voltage-gated channels act like _ in a computer

A

transistors

206
Q

The Nernst equation can only be used if…

A

only 1 ion is permeable across the membrane

207
Q

When a neuron is at rest, it is most permeable to _

A

potassium

208
Q

Sodium is permeable 35 times _ than potassium along the membrane

A

less than potassium, therefore resting membrane potential is closer to potassium equilibrium potential than the sodium one

209
Q

For Na+, the electrical force is into the cell, the chemical force is also into the cell. The netforce is +60mV: Na+ flows into the cell but the membrane has…which prevents it from doing it as much as it wants

A

low permeability to Na+

210
Q

Why is the electrical force and chemical force for Na+ at resting membrane potential both into the cell?

A

the chemical force is strong to go into the cell, and the electrical force (-70 mv) compels Na+ to also go in the cell

211
Q

Transmission of electrical signal exists through the _ membrane

A

biological

212
Q

_d stimuli are graded potentials not strong enough to inspire an action potential

A

subthreshold

213
Q

_ stimuli in a graded potential generates an action potential

A

threshold stimuli

214
Q

Threshold is mapped with y-axis as membrane potential (mV) vs. x-axis as _

A

time (msec)

215
Q

Temporal summation can be visualized as…

A

telegraph (one stimulus repeated)

216
Q

Spatial summation can be visualized as….

A

multiple people talking at once

217
Q

Do temporal and spatial summation happen together in nature?

A

yes, for the most part. it is rare that only one of them exists at a time

218
Q

_ _s record the value of a membrane potential

A

intracellular electrodes

219
Q

What happens during depolarization in an action potential?

a. sodium rushes out and the membrane potential becomes negative
b. sodium rushes in and the membrane potential becomes positive
c. potassium rushes in and the membrane potential becomes positive
d. potassium rushes in and the membrane potential becomes negative

A

b. sodium rushes in and the membrane potential becomes positive

220
Q

During repolarization in an action potential, what happens to the membrane permeability of sodium (Na+) and potassium (K+)?

a. permeability of K+ and Na+ increases
b. permeability of K+ and Na+ decreases
c. Permeability of K+ increases and permeability of Na+ decreases
d. Permeability of K+ decreases and permeability of Na+ increases

A

c. Permeability of K+ increases and permeability of Na+ decreases

221
Q

An action potential travels all the way down an axon. Where does a graded potential travel?

a. all the way down an axon as well
b. dendrites, cell body, and sensory receptors
c. synapse, hillocks, and terminals
d. nowhere; graded potentials do not travel

A

b. dendrites, cell body, and sensory receptors

222
Q

An action potential either fires or not (all-or-none), and it maintains its strength as it travels. How does a graded potential compare?

a. It is all-or-none, and it maintains its strength as it travels.
b. It is weak, depending on the stimulus strength, but maintains its strength as it travels.
c. It is all-or-none, but it weakens as it travels.
d. It is weak, depending on the stimulus strength, and dissipates away from the stimulus.

A

d. It is weak, depending on the stimulus strength, and dissipates away from the stimulus.

223
Q

Action potentials use voltage-gated channels. Which type of channels are involved in producing a change in the membrane voltage in graded potentials?

a. voltage-gated only
b. ligand-gated and mechanically gated
c. mechanically gated only
d. ligand-gated only

A

b. ligand-gated and mechanically gated

224
Q

What is the difference between excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs)?

a. IPSPs depolarize the cell and EPSPs hyperpolarize the cell.
b. EPSPs are all-or-none and IPSPs are graded
c. EPSPs depolarize the cell and IPSPs hyperpolarize the cell
d. EPSPs are fast and IPSPs are slow.

A

c. EPSPs depolarize the cell and IPSPs hyperpolarize the cell

225
Q

What is a difference between temporal and spatial summation?

a. In temporal summation, ionotropic responses are critica
b. In spatial summation, the postsynaptic potentials happen at the same time.
c. In spatial summation, metabotropic responses are critical.
d. In temporal summation, the postsynaptic potentials happen at the same time.

A

b. In spatial summation, the postsynaptic potentials happen at the same time.

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