Nervous System Flashcards
1
Q
what does the abbreviation “CNS” stand for
A
central nervous system
2
Q
what does the CNS consist of
A
billions of neurons in the brain and spinal cord
3
Q
what are tracts
A
bundles of axons in the CNS
4
Q
axons carry impulses in only one direction in the CNS.
what are those directions and the proper terms for them
A
ascending: sensory impulses traveling to the brain from the spinal cord
*to the brain
descending: motor impulses traveling from the brain to the spinal cord
*to the spinal cord
5
Q
what does the abbreviation “PNS” stand for
A
peripheral nervous system
6
Q
what does the PNS consist of
A
all the nerves and receptors outside of the brain and spinal cord
7
Q
what are nerves
A
bundles of axons in the PNS
8
Q
axons carry impulses in only one direction in the PNS.
what are those directions and the proper terms for them
A
afferent: sensory impulse traveling towards the CNS from PNS
*towards spine
efferent: motor impulses traveling from the CNS to the PNS
*towards receptors
9
Q
what does autonomic efferent mean
A
involuntary impulses to smooth muscle, glands, and cardiac muscle
10
Q
what does somatic efferent mean
A
voluntary major impulses to skeletal muscle
11
Q
in the PNS there are sensory (________) and motor (________) neurons
A
afferent; efferent
12
Q
in the CNS there are sensory (_____) and motor (_____) neurons
A
ascending; descending
13
Q
what are the functions of neurons
A
sensory, motor, and integrative pathways
14
Q
there are cranial nerves (enter/exit brain) and spinal nerves (enter/exit) spinal cord
are these nerve part of the CNS or PNS
A
PNS
15
Q
what are the two types of cells in the nervous system
A
neurons and neuroglia (glial cells)
16
Q
what is the general function of a neuron
A
to carry impulses across the body in response to stimuli
17
Q
what is the general function of neuroglia
A
to support the neurons
18
Q
what are the general functions of astrocytes
A
serve as a blood-brain barrier
potassium/sodium/carbon dioxide balance
metabolism of neurotransmitters
repair of damaged areas in CNS
neuronal connections during development
19
Q
what is the general function of microglia
A
phagocytes that digest debris
20
Q
what is the general function of ependymal cells
A
ciliated cells that line spaces in the brain and aid with movement of cerebrospinal fluid
21
Q
what is the general function of oligodendrocytes
A
they make the myelin sheath in the CNS
22
Q
what is a myelin sheath and what is its purpose
A
a phospholipid covering around axons of neurons in the CNS and PNS
they aid in conduction of electrical impulses and isolation of the neuron
23
Q
what are satellite cells
A
cells in the PNS that support the neurons in ganglia
24
Q
what are ganglia
A
nerve cell clusters in the PNS
25
what is a ganglion
group of neural cell bodies in the PNS
26
what are Schwann cells
cells that make the myelin sheath in the PNS
27
what is another name for Schwann cells
neurolemmocytes
28
satellite cells are analogous to which cells in the CNS
astrocytes
29
Schwann cells are analogous to which cells in the CNS
oligodendrocytes
30
why are neurtubules important in a neuron
they provide internal support to the neuron
31
what is the purpose of the myelin sheath
insulation
make impulses faster
save ATP
32
which cell makes the myelin sheath in the CNS
oligodendrocytes
33
which cell makes the myelin sheath in the PNS
Schwann cells
34
are all neurons in the PNS and CNS myelinated
no there are some unmyelinated neurons as well
35
does the CNS contain neurolemma
no
36
does the PNS contain neurolemma
yes
37
what is neurolemma
the nucleated cytoplasmic (outer) layer of the Schwann cells
38
unmyelinated axons conduct impulses ________ than myelinated ones
a. faster
b. slower
slower
39
how are neurons classified
by structure and function
40
what are the types of structures neurons can have in the nervous system
mulitpolar - many extensions
bipolar - 2 extensions
unipolar - single extension
41
what does it mean for a neuron to be classified structurally
it is based on the number of extensions on the soma of a neuron
42
what does it mean for a neuron to be classified functionally
based on the type of impulse that is carried by the neuron
43
what are the types of functional names a neuron can have
sensory
motor
association or integrative
44
define resting membrane potential
the difference in voltage between the inside and outside
45
what is the resting potential voltage in a neuron
-70 mV
46
why is the inside negatively charged relative to the outside of the membrane
there are many large proteins that are anions with a negative charge
47
what is the function of the Na+/K+ pump
to maintain resting potential
it pumps out potassium and takes in sodium
48
does the Na+/K+ pump require ATP
yes
49
what does the somatic nervous system do
carries sensory information from the PNS to the brain then to the skeletal muscles
50
does the somatic nervous system innervate with the skeletal system
yes
51
what does the autonomic nervous system do
involuntary movement of impulses
52
does the autonomic nervous system innervate with cardiac and smooth muscle
yes
53
what is the enteric nervous system
nervous system of the gastrointestinal tract that can work independently from the somatic and autonomic
54
can the enteric nervous system be influenced by the autonomic nervous system
yes
55
what is depolarization
reversing the charge
*negative to positive
56
what is repolarization
reversing the reverse charge and putting it back to normal
*positive back to negative
57
what happens to the membrane during depolarization
the membrane becomes more permeable to Na+ (sodium)
58
what happens to the membrane during repolarization
the membrane potential is reestablished
59
how is depolarization caused
Na+ rushes into the cell bringing a positive charge into the cell so the membrane becomes more positive
60
what are voltage sensitive gates
channels that need to meet a threshold in order to function
61
what is the threshold for voltage sensitive channels
-55mV
textbook: -60mV
62
how does the cell reestablish membrane potential
K+ is positive and it leaves the cell
63
what is hyperpolarization
membrane potential that becomes more negative than the resting membrane potential
64
what is the refractory period
the time at which you can't send action potentials
65
in an action potential, when does the refractory period occur
during depolarization
66
what is the all or none response
cells will excite to its greatest capacity through each action potential
67
what is saltatory conduction
action potentials jumping from node to node
68
what are the nodes in between the myelin sheaths called in saltatory conduction
nodes of Ranvier
69
in myelinated axons the action potential only occurs at the nodes of _______. the myelin insulates the rest of the axon
Ranvier
70
what are the advantages of saltatory conduction
fast
saves ATP
71
what do fast nerves look like
large diameter with myelin
72
speed of action potentials increases with _______
temperature
73
what are the different types of nerve fibers
A fibers - large diameter
B fibers - contain myeline
C fibers - no myelin
74
what is continuous conduction
slow action potentials that occur in unmyelinated neurons
75
what is a presynaptic neuron
the neuron before the synapse
76
what is a postsynaptic neuron
the neuron after the synapse
77
what is a chemically gated channel
a channel where the opening of said channel is caused by a chemical binding to a receptor
78
what is a voltage gated channel
a channel where the opening of said channel is caused by a change in voltage
79
what does ionotropic mean
neurotransmitters that bind to a receptor that also serves as a channel
80
what does metabotropic mean
neurotransmitters binds to a receptor that triggers the opening of a channel
81
what is an inhibitory postsynaptic potential
the possibility for a neurotransmitter to bind to its receptor and not move it closer to the threshold
82
what is a graded potential
the neurotransmitters binding to their receptors causing a local change
83
what is an excitatory postsynaptic potential
a graded potential that is moving the voltage towards the threshold
84
what is glutamine
the most common excitatory neurotransmitter
85
what is GABA
the most common inhibitory neurotransmitter
86
what fires the action potential when the threshold is reached
the axon hillock
87
what is a direct electrical synapse
a gap junction in cardiac muscle
88
what is a chemical synapse
where an impulse can only travel in one direction
89
list the events that occur at a synapse
1. action potential is fired
2. action potential reaches the axon end bulb and triggers calcium to flow into the bulb through voltage sensitive calcium channels
3. calcium influx triggers the movement of vesicles with neurotransmitters towards the membrane of the axon terminal
4. the neurotransmitter is released by exocytosis and diffuses across the synaptic cleft
5. the neurotransmitter attaches to a receptor on the postsynaptic membrane and causes a change in the resting membrane potential
90
is the neurotransmitter in the nervous system always acetylcholine
no
91
what is the purpose of having numerous neurotransmitters in the body
for different functions/reactions needed in response to different stimuli
92
what changes on the postsynaptic membrane can be caused by neurotransmitters
the change in voltage
93
the neurotransmitter acetylcholine causes _____ influx on the skeletal muscle membrane. the ____ influx depolarizes the motor end plate and initiates the ________
Na+
Na+
action potential
94
some neurotransmitters caused the membrane potential of the postsynaptic cell to move closer to the threshold.
what is another words for it moving closer to the threshold
excitatory
95
some neurotransmitters caused the membrane potential of the postsynaptic cell to move away from the threshold.
what is another word for it moving away from the threshold
inhibitory
96
is acetylcholine release at the neuromuscular junction always excitatory or inhibitory
excitatory
97
what is a converging circuit
a lot of presynaptic neurons and one postsynaptic neuron
98
do excitatory neurotransmitters depolarize or repolarize the membrane
depolarize
99
do inhibitory neurotransmitters depolarize or hyperpolarize the membrane
hyperpolarize
100
excitatory neurotransmitters cause the inside of the cell to move closer to the threshold of ______
-55mV
101
what determines if an action potential is generated
the axon hillock summates all of the information from the neurons synapses and determines if the action potential will be generated
102
what is the trigger zone
zone of which if the sum reaches the potential of -55mV or higher causing an action potential
103
what is temporal summation
repeated impulses over time
104
what is spatial summation
several neurons firing at once
105
what is summation
the process that determines whether or not an action potential will be generated by the combined effects of excitatory and inhibitory signals
106
what is facilitation
axon hillock moving closer to the threshold in a neuron
107
what are examples of neurotransmitters
acetylcholine
amino acids glutamate and GABA
noradrenaline
norepinephrine
dopamine
serotonin
nitric oxide
endorphins
enkephalins
108
1. neurotransmitter at the neuromuscular junction (excitatory)
2. neurotransmitter in the autonomic nervous system
3. broken down by cholinesterase
4. nitocine stimulates these receptors
what type of neurotransmitter do these traits define
acetylcholine
109
1. most common inhibitory neurotransmitter in the brain
1.A. valium increases these levels
2. is an amino acid
what type of neurotransmitter do these traits define
GABA
110
1. most common excitatory neurotransmitter in the brain
2. is an amino acid
what type of neurotransmitter do these traits define
glutamine
111
1. can also be norepinephrine
2. neurotransmitter in the autonomic nervous system
3. important neurotransmitter in the brain for arousal from sleep
what type of neurotransmitter do these traits define
noradrenaline
112
1. muscle control
2. creates the "high" of certain drugs and plays a role in addiction
3. role in memory
what type of neurotransmitter do these traits define
dopamine
113
1. role in sleep, mood, and appetite
2. important neurotransmitter in the GI tract
what type of neurotransmitter do these traits define
serotonin
114
1. gas
2. smooth muscle relaxer
what type of neurotransmitter do these traits define
nitric oxide
115
1. neuropeptides
2. may be released with neurotransmitters
3. affect the function of neurotransmitters
4. natural pain killers
what type of neurotransmitters do these traits define
endorphins and enkephalins
116
what is the type of nervous system that innervates smooth muscle, glands, and cardiac muscle
autonomic nervous system
117
what tissues are innervated by the somatic nervous system
skeletal muscle
118
what are the CNS neuroglial cell that can phagocytize
mircoglia
119
what is the CNS neuroglial cell that helps control levels of K+ in the brain
astrocytes
120
what is the neuroglial CNS cell that only allows fat-soluble substances to leave the blood and enter the brain
astrocyte
121
what is the neuroglial CNS cell that can help metabolize certain neurotransmitters
astrocyte
122
what is the neuroglial cell in the CNS that makes myelin
oligodendrocyte
123
what is the neuroglial cell in the CNS that lines spaces within the brain
ependymal cells
124
neuroglial cell in PNS that makes myelin
Schwann cell
125
what is the nucleated, cytoplasmic layer of Schwann cell
neurilemma
126
what is another name for the cell body of neuron
soma
perikaryon
127
rough ER in the perikaryon (soma) of a neuron goes by this name
Nissl Bodies
128
a neuron with more than two extensions off of the soma
multipolar neuron
129
a neuron with 2 extensions off of the soma
bipolar neuron
130
a neuron with 1 extension off of the soma
unipolar neuron
131
what is the stage in a twitch called when there is a change in charge across the membrane of a neuron due to Na+ influx
depolarization
132
what is the name for the stage in a twitch when there is a reestablishment of membrane potential in a neuron due to K+ outflow
repolarization
133
what is the term used to describe the propagation of the action potential at nodes of Ranvier only
saltatory conduction
134
what are common neurotransmitters in the autonomic nervous system
noradrenaline, norepinephrine, acetylcholine
135
what is a type of neurotransmitter that blocks plain
endorphins
136
what is the most common excitatory neurotransmitter in the brain
glutamate
137
what is the most common inhibitory neurotransmitter in the brain
GABA
138
what is a neurotransmitter that plays an important role in sleep and mood
serotonin
139
what is a neurotransmitter that is a gas and relaxes smooth muscle
nitric oxide
140
what is the term used to describe the change in resting membrane potential when it becomes more negative
hyperpolarization
141
what is the term used to describe a partial hyperpolarization caused by a neurotransmitter at the post synaptic membrane
IPSP
inhibitory post synaptic potential
142
what is the word for combination of EPSPs (excitatory postsynaptic potentials) that makes it easier for the postsynaptic membrane to reach threshold
summation
143
what type of neuroglial cell in the PNS that maintains the environment around neurons
satellite cell
144
what is the threshold amount that will open the Na+ voltage-gated channel at the node of Ranvier
-55mV
145
where would be a place where a chemically-gated channel can be found on a neuron
the post synaptic neuron membrane
