Intro to Nervous System Flashcards
1
Q
T/F: The autonomic nervous system as well as the somatic nervous system are both motor nervous systems.
A
True
2
Q
T/F: The afferent nervous system is synonymous with the sensory nervous system; this system conducts nerve signal toward or into the CNS.
A
True
3
Q
T/F: The efferent nervous system conducts nerve signals toward or into the CNS.
A
False: efferent neurons conduct signals away from the CNS
4
Q
The sympathetic and parasympathetic nervous systems typically are antagonistic systems, each one undoing what the other does.
A
True; some exceptions such as sexual response
5
Q
The _____ nervous system is responsible for what is colloquially termed the “rest-and-digest” response.
A
parasympathetic
6
Q
The ____ nervous system is responsible for what is colloquially termed the “fight-or-flight” response.
A
sympathetic
7
Q
The ___ nervous system is that portion of the peripheral nervous system that is composed of nerve fibers which innervate skeletal muscle.
A
somatic
8
Q
____ neurons are neurons which conduct signals toward the CNS from receptors located throughout the body.
A
Afferent or Sensory
9
Q
___ neurons are neurons which conduct signals from the CNS to effectors located throughout the body.
A
Efferent or Motor
10
Q
T/F: There are no nerves in the central nervous system.
A
True - nerves are clusters of neuronal axons in the PNS. They can’t be found in the CNS.
11
Q
T/F: Nerves are only found in the peripheral nervous system.
A
True: bundles of axons in the CNS are known as tracts.
12
Q
____ are bundles of neuron cells processes (axons) in the CNS.
A
Tracts
13
Q
____ are bundles of neuron cells processes (axons) in the PNS.
A
Nerves
14
Q
____ are clusters of neuronal cell bodies in the CNS.
A
Nuclei
15
Q
____ are clusters of neuronal cell bodies in the PNS.
A
Ganglia
16
Q
____ transport, which moves cellular material from bouton to neuronal cell body, is the vehicle used by some viruses and neurotoxins to quickly and directly reach the CNS.
A
Retrograde
17
Q
____ refer to the many bulbous swellings that terminate the neuronal axon; these structures interact with downstream effector cells, such as muscle or gland cells, or other neurons.
A
Boutons, synaptic knobs, or synaptic terminals
18
Q
T/F: The spinal cord is the largest nerve in the human body and is part of the peripheral nervous system
A
False: the spinal cord is not a nerve (nerves lie in PNS)
19
Q
___ neurons are by far the most abundant type of neurons in the human body.
A
Association (or interneurons)
20
Q
T/F: All incoming sensory information leads to a conscious awareness of the stimulus.
A
False: ex. proprioception does not make it to conscious awareness
21
Q
____ are the receptors which respond to pain; synonym for “pain receptors”.
A
Nociceptors
22
Q
____ are the receptors which respond to pressure and pressure changes.
A
Baroreceptors
23
Q
___ is the neurotransmitter used by most nociceptors in communicating with CNS neurons.
A
Substance P
24
Q
____ are the receptors which respond to the presence of specific chemicals, such as oxygen in the blood or those molecules detected in smell.
A
Chemoreceptors
25
____ are the receptors which respond to overall solute concentrations; they detect, for example, the overall solute concentration of the blood and are involved in our feelings of thirst.
Osmoreceptors
26
___ are the receptors largely responsible for the sense of smell.
Chemoreceptors (also involved in sense of taste)
27
___ are the environmental cues that cause sensory receptors to respond; heat, cold, pressure, light, sound, and tissue destruction are examples.
Stimuli
28
Aspirin inhibits ____ production, a fact that explains some of aspirin's analgesic effects since fewer ____ would equate with less hyperalgesia.
prostaglandin; prostaglandins,
29
T/F: Nociceptors can be sensitized by the presence of prostaglandins.
True
30
____ refers to the body's non-conscious awareness of its musculoskeletal system, e.g., muscle length and contraction, as well as the stretching and compression in every joint capsule; this information does not synapse in the thalamus and does not break through to conscious awareness.
Proprioception
31
____ is a collective term for all of the general senses, including touch, heat, cold, pain, pressure, vibration, etc; many (but certainly not all) of the associated receptors are found in the skin.
Somatosensation
32
___ refers to increased sensitivity to pain; stimuli that were once perceived as non-painful now seem painful.
Hyperalgesia
33
T/F: A myelin sheath is essentially a solid tube of greasy fats secreted around axons by Schwann cells and astrocytes.
False: myelin sheaths are made by Schwann cells and oligodendrocytes. Myelin sheaths consist of coils of oligodendrocyte or Schwann cell membrane.
34
T/F: Myelin sheaths electrically couple adjacent axons together, so that a nerve signal propagating down one axon can "jump" to its neighbors and propagate down them as well.
False - just the opposite. Myelin sheaths are electrical insulators -> inhibit signals from jumping to adjacent axons. They function like the plastic insulation around an electrical wire.
35
Regions of the brain and spinal cord containing dense collections of myelinated fibers are referred to as ____.
white matter
36
Regions of the brain and spinal cord containing dense collections of unmyelinated fibers are referred to as ____.
gray matter
37
The ___ are gaps in the myelin sheaths around neurons, regions where adjacent Schwann cells do not touch each other.
nodes of Ranvier
38
T/F: The maintenance of a potential difference across a resting neuron membrane requires active transport of sodium and potassium.
True: it also requires a lot of ATP energy
39
___ refers to the voltage difference that usually exists across a cell membrane as a result of asymmetrical ion distributions; in biology, this difference is usually measured in millivolts (mV).
Membrane potential
40
__ refers to the voltage difference that usually exists across a neuronal cell membrane when that cell is not involved in nerve signaling; a typical value is on the order of -70 mV.
Resting potential
41
___ channels are normally closed but open in response to a signal.
Gated
42
___ channels are always open and therefore provide a means for small numbers of ion (molecules) to constantly cross cell membranes.
Leakage
43
A typical value for the resting membrane potential of a neuronal cell is about ___.
- 70mV
44
T/F: Depolarization is a change in the membrane potential toward a more negative value.
False: depolarization is a change in membrane potential toward a more positive value
45
T/F: Graded potentials are always excitatory.
False: they can be either excitatory or inhibitory
46
A graded potential is characterized by ______.
the potential change (change in voltage) being related to the magnitude of the stimulus.
47
T/F: Both action potentials and graded potentials are conducted decremental, i.e. they fade in intensity with increasing distance from their initiation point.
False: this is true of graded potentials, but false of action potentials - they do not lose strength as they propagate down an axon
48
During the absolute refractory period, it is possible to generate a second action potential if the stimulus is sufficiently intense.
False: consider the absolute refractory period as having a threshold of infinity, so that no stimulus would be intense enough to start another action potential
49
The ___ is the region of a neuron at which action potentials are initiated.
trigger zone
50
What is the reason that refractory periods exist in neurons?
It takes time for the ion channels to open, close, and for resting potential to be re-established by pumping and mass action of ions.
51
T/F: Action potentials move faster in myelinated axons than in unmyelinated ones.
True: up to 150x faster
52
____ is the method by which action potentials propagate in myelinated axons.
Saltatory conduction
53
T/F: One single neuron can simultaneously play the role of a pre-synaptic and a post-synaptic neuron.
True
54
T/F: Chemical synapses may be either excitatory or inhibitory, depending, in part, on the neurotransmitter used.
True
55
T/F: Synapses occur only between axon terminals and dendrites.
False: synapses can occur between axons and other axons, axons and cell bodies, dendrites and dendrites
56
A _____ neuron conducts nerve signals, and hence information, toward or into a given synapse.
presynaptic
57
A(n) ____ is the junction between two neurons across which communication occurs.
synapse
58
The ____ is the fluid-filled space (a few tens of nanometers wide) which separates a pre-synaptic neuron from a post-synaptic neuron at a synapse.
synaptic cleft
59
___ neurons are neurons which conduct signals away from a synapse.
Postsynaptic
60
___ neurons are neurons which conduct signals toward a synapse.
Pre-synaptic
61
___ is an adjective that means pertaining to the use, production, possession, or release, of histamine.
Histaminergic
62
____ is an adjective that means pertaining to the use or production of epinephrine.
Adrenergic
63
T/F: The trigger zone of a neuron summates excitatory and inhibitory postsynaptic potentials, initiating an action potential if threshold is reached.
True
64
T/F: A depolarized membrane is more likely to reach threshold than a hyper polarized one.
True
65
An (EPSP or IPSP) would tend to depolarize a post-synaptic neuron.
EPSP
66
____ is the process by which the trigger zone of a neuron adds together all the excitatory and inhibitory post-synaptic potentials in a neuron on a moment-by-moment basis in order to decide whether or not to fire off an action potential.
Summation
67
An IPSP (inhibitory postsynaptic potential) is inhibitory because ____.
it hyper polarizes the postsynaptic membrane
68
The histamine ____ receptor is located in the gastric mucosa and is inhibited by such anti-histamine drugs as ranatidine and cimetidine.
H2 (H1 receptor is involved in allergies such as hayfever)
69
T/F Supporting cells are a type of nerve tissue
True
70
T/F Neurons and supporting cells are both excitable cells capable of generating nerve signals
True
71
T/F Supporting cells, like neurons, are capable of generating nerve signals
False
72
T/F Astrocytes may play a role in making nutritional exchanges between capillaries and neurons
True
73
T/F Astrocytes help to control the chemical environment around neurons
True
74
T/F Astrocytes often form myelin sheaths around CNS axons
False
75
______ are glial cells in the CNS that support neurons physically, chemically, and nutritionally, and may also help regulate the ionic composition of the extracellular fluid.
Astrocytes
76
____ are glial cells that, via their cilia action, help circulate cerebrospinal fluid in the CNS.
Ependymal cells
77
___ are glial cells with many projections radiating from the cell body, making the cells distinctly star-shaped in appearance.
Astrocytes
78
___ are the phagocytes of the CNS; they function as macrophages within the CNS.
Microglial cells
79
___ are the most abundant type of glial cells in the CNS.
Astrocytes
80
___ are glial cells that form myelin sheaths in the CNS.
Oligodendrocytes
81
___ are glial cells that function as epithelial cells in the CNS.
Ependymal cells
82
____ are glial cells that form myelin sheaths in the PNS
Schwann cells
83
___ are glial cells lining the cavities (ventricles of the brain, central canal of spinal cord) of the CNS
Ependymal cells
84
Dendrites neither initiate nor propagate _____
action potentials
85
Dendrites only conduct short-distance signals called ____
graded potentials
86
T/F Like axons, dendrites may be myelinated
False
87
Dendrites conduct electrical signals toward ____
the neuron cell body
88
T/F Axons are always myelinated
False
89
___ are receptors which respond to overall solute concentration
Osmoreceptors
90
___ are receptors which respond to pressure or pressure changes
Baroreceptors
91
___ are receptors which respond to individual chemicals or a small group of similar chemicals in solution
Chemoreceptors
92
___ are receptors which respond to temperature or temp changes
Thermoreceptors
93
___ are receptors which advise the brain on the positions and movements of our muscles and joints; this information is not bound for conscious awareness
Proprioceptors
94
___ are receptors which respond to physical deformation by mechanical forces
Mechanoreceptors
95
___ are receptors which respond to light energy
Photoreceptors
96
___ are receptors which respond to potentially damaging stimuli; pain receptors
Nociceptors
97
Depending on conditions, a given ion may move ___ its chemical gradient but ____ its electrical gradient, or vice versa.
along; against
98
The prices driving an ion across the neuron cell membrane consist of both a ___ and ___
chemical gradient; electrical gradient
99
The sodium EChGr is directed from ____ to ___
outside the cell to inside the cell
100
When sodium channels open and sodium crosses the neuron cell membrane, the sodium ions are moving ____ the electrical gradient.
along or with
101
T/F The potassium electrochemical gradient is directed from the outside into the cell.
False
102
____ are channel transporters which open or close in response to changes in the membrane potential
Voltage-gated channels
103
___ are a class of channel transporters which do not require ATP but rather use diffusion as the driving force to move ions or molecules across a membrane
Passive channels
104
___ are channel transporters which are always open
Leakage channels
105
___ are active transporters: ATP-requiring transporters which are able to concentrate molecules/ions across a membrane (against the electrochemical gradient)
ATP-ases (pumps)
106
___ are channel transporters which open or close in response to the binding and unbinding of some type of chemical signal such as a neurotransmitter
Ligand-gated channels
107
____ are channel transporters which open or close in response to physical deformation
Mechanically-gated channels
108
Action potentials: IPSPs and EPSPs are summated, causing the moment-to-moment membrane potential to fluctuate within a range of sub-threshold values. The membrane potential ____ from sub-threshold to threshold. The _____-gated Na+ channels open and eventually close, resulting in local ____ of the membrane. The voltage-gated ___ channels open and eventually close, resulting in local hyperpolarization of the membrane. The local membrane returns to its resting state as __ and ___ return to their normal resting concentrations.
depolarizes; voltaged-gated; depolarization; K+; Na+ and K+
109
Describe difference b/t graded potentials and action potentials re: intensity, distance, & propagation
Graded: intensity related to strength of stimulus; useful for short-distance communication; fade with distance from point of stimulus; do not self-propagate
Action: all are same in strength; long distance communication; do not fade w distance; self-propagate
110
T/F Graded potentials are mediated by ion channels other than voltage-gated, while action potentials always involve voltage-gated channels
True
111
___, ___, and ___, are biogenic amine neurotransmitters
norepinephrine, dopamine, serotonin
112
Name categories of recognized neurotransmitters.
Acetylocholine, Amino acids, peptides, biogenic amines, novel messengers such as NO, CO, and ATP
113
T/F Fatty acids are a category of neurotransmitters.
False
114
Transmission of nerve signal across a synapse:
1. The action potential reaches the axon terminal. ___-gated Calcium channels in the _____ axonal terminal open, allowing calcium to flood into the synaptic knob. Increased calcium levels in the synaptic knob induce calcium-dependent exocytosis of neurotransmitter-containing ___ ____, causing neurotransmitter to _____. Neurotransmitter binds to the receptors in the __-__ ____. Ion channels in the __ - ___ membrane open, allowing ions of a specific type to enter or leave the post-synaptic neuron, resulting in a post-synaptic _____. Neurotransmitter de-binds from the receptor on the _____ membrane. Neurotransmitter is cleared from the ______, and the effects of the recently-graded post-synaptic potential diminish.
```
Voltage-gated
pre-synaptic
synaptic vesicles
flood the synaptic cleft
post-synaptic membrane
post-synaptic
graded potential
post-synaptic
synaptic cleft
```
115
Name 3 Catecholamines.
Epinephrine, Norepinephrine, Dopamine
116
____ is a neurotransmitter produced from the amino acid tryptophan.
Serotonin
117
Serotonin is degraded by ____
MAO
118
Ephinephrine and Norepinephrine are degraded by ___ and ___
MAO and COMT
119
Acetylocholine is degraded by ____
AChE
120
T/F mACh receptors bind the fungal toxin muscarine, while nACh receptors bind the alkaloid nicotine.
True
121
T/F mACh receptors function via slower-acting second messenger systems, while each receptors are faster-acting sodium channels
True
122
T/F mACh receptors may be either stimulatory or inhibitory, depending on the second messenger system used, while each receipts are always stimulatory.
True
123
T/F mACh receptors are found in skeletal muscle, while nACh receptors occur in smooth and cardiac muscle.
False
124
Alpha, Beta-1, Beta-2, and Beta-3 are examples of _____ receptors.
Adrenergic
125
____ receptors are distributed in the heart; activation causes ____ heart rate and ___ force of contraction
Beta-1
126
___ receptors are especially abundant in non-heart blood cells; activation causes excitation and thus ___.
Alpha; vasoconstriction
127
___ receptors are distributed in adipose tissue; activation causes breakdown of ___ and releases ____ into the blood
Beta-3; fat; fatty acids
128
___ are especially abundant in lungs and blood vessels of the heart; activation causes inhibition and thus _____ and bronchodilation.
Beta-2; vasodilation
