7 Nervous System Flashcards
1
Q
nervous system
A
the controlling and communicating system of the body
2
Q
the controlling and communicating system of the body
A
the nervous system
3
Q
the three overlapping functions of the nervous system
A
sensory input - monitor changes
integration - processes and interprets
motor output - effects, causes a response
4
Q
structural classification of the nervous system consists of what two subdivisions?
A
central nervous system
peripheral nervous system
5
Q
what does the central nervous system consist of?
A
the brain and the spinal cord
6
Q
what part of the nervous system is the brain a part of?
A
the central nervous system
7
Q
what part of the nervous system is the spinal cord a part of?
A
the central nervous system
8
Q
what is the role of the brain and spinal cord in the nervous system?
A
acts as the integrating and command centers of the nervous system
9
Q
acts as the integrating and command centers of the nervous system
A
brain and spinal cord
10
Q
what is the role of the central nervous system?
A
interprets incoming sensory information and issues instructions based on past experiences and current conditions
11
Q
interprets incoming sensory information and issues instructions based on past experiences and current conditions
A
the central nervous system
12
Q
the part of the nervous system outside the central nervous system
A
peripheral nervous system
13
Q
the peripheral nervous system
A
the part of the nervous system outside the CNS; consists mainly of nerves that extend from the brain and spinal cord which serve as communication lines to and from the entire body
14
Q
consists mainly of nerves that extend from the brain and spinal cord which serve as communication lines to and from the entire body
A
the peripheral nervous system
15
Q
spinal nerves
A
part of PNS; carry impulses to and from the spinal cord
16
Q
part of PNS; carry impulses to and from the spinal cord
A
spinal nerves
17
Q
cranial nerves
A
part of PNS; carry impulses to and from the brain
18
Q
part of PNS; carry impulses to and from the brain
A
cranial nerves
19
Q
link all parts of the body by carrying impulses from the sensory receptors to the CNS and from the CNS to the appropriate glands of muscles
A
the nerves of the PNS
20
Q
the functional classification of the nervous system is only concerned with which part?
A
only with PNS structures
21
Q
the two principal subdivisions of the Peripheral nervous system
A
sensory (afferent) division
motor (efferent) division
22
Q
sensory (afferent) division of the PNS
A
consists of nerves that convey impulses TO the CNS from sensory receptors throughout the body; keeps the CNS constantly informed of events going on both inside and outside the body
23
Q
consists of nerves that convey impulses TO the CNS from sensory receptors throughout the body
A
sensory (afferent) division of the PNS
24
Q
keeps the CNS constantly informed of events going on both inside and outside the body
A
sensory (afferent) division of the PNS
25
motor (efferent) division of the PNS
consists of nerves that carry impulses FROM the CNS to effector organs, muscles and glands; carry impulses that bring about a motor response
26
consists of nerves that carry impulses FROM the CNS to effector organs, muscles and glands
motor (efferent) division of the PNS
27
carry impulses from the CNS that bring about a motor response
motor (efferent) division of the PNS
28
the two subdivisions of the motor division of the PNS
somatic (voluntary) nervous system
| autonomic (involuntary) nervous system
29
another name for the somatic nervous system
voluntary nervous system
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another name for the autonomic nervous system
involuntary nervous system
31
another name for the voluntary nervous system
somatic nervous system
32
another name for the involuntary nervous system
autonomic nervous system
33
somatic nervous system
allows us to consciously control our skeletal muscles; voluntary nervous system
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allows us to consciously control our skeletal muscles
somatic nervous system
35
autonomic nervous system
regulates events which are automatic, such as glands and cardiac muscle; has two parts, sympathetic and parasympathetic
36
regulates events which are automatic, such as glands and cardiac muscle
autonomic nervous system
37
has two parts, sympathetic and parasympathetic
autonomic nervous system
38
what are the principal types of cells making up nervous tissue?
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supporting cells (neuroglia, glia, glial cells)
neurons (nerve cells)
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39
other names of supporting cells in nervous tissue
neuroglia
glia
glial cells
40
another name for neuron cells in nervous tissue
nerve cells
41
the supporting cells in the CNS are collectively called this
neuroglia, glia, or glial cells
42
functions of the neuroglia
support, insulate and protect the delicate neurons; different types also have special functions
43
support, insulate and protect the delicate neurons
neuroglia
44
astrocytes
star-shaped cells that account for nearly half of the neural tissue; projections cling to neurons, bracing them and anchoring them to their nutrient supply lines, the blood capillaries; hold neurons apart
45
star-shaped cells that account for nearly half of the neural tissue
astrocytes
46
their projections cling to neurons, bracing them and anchoring them to their nutrient supply lines, the blood capillaries
astrocytes
47
glia which hold the neurons apart
astrocytes
48
microglia
glia which are phagocytes; monitor the health of nearby neurons; dispose of debris including dead brain cells and bacteria
49
glia
supporting cells of the CNS
50
glia which are phagocytes
microglia
51
monitor the health of nearby neurons; dispose of debris including dead brain cells and bacteria
microglia
52
ependymal cells
glial cells that line the central cavities of brain and spinal cord; the beating of their cilia helps to circulate the cerbralspinal fluid that fills that cavities and forms a protective cushion around the CNS
53
glial cells that line the central cavities of brain and spinal cord
ependymal cells
54
the beating of their cilia helps to circulate the cerbralspinal fluid that fills that cavities and forms a protective cushion around the CNS
ependymal cells
55
oligodendrocytes
glia that wrap their flat extensions (processes) tightly around the nerve fibers, producing fatty insulating covers called myelin sheaths
56
glia that wrap their flat extensions (processes) tightly around the nerve fibers
oligodendrocytes
57
glia that produce fatty insulating covers called myelin sheaths
oligodendrocytes
58
myelin sheaths
fatty insulating covers around nerve fibers, made up of oligodendrocytes (glia) in the CNS, and schwann cells in the PNS
59
fatty insulating covers around nerve fibers, made up of oligodendrocytes (glia)
myelin sheaths
60
compare glial cells and neurons
both similar structurally-both have cell extensions
glia unable to transmit nerve impulses
glia never lose ability to divide like neurons do
61
why are most brain tumors made up of glial cells and not neurons?
because glia never lose their ability to divide, neurons do
62
supporting cells in the PNS
schwann cells
| satellite cells
63
schwann cells
form the myelin sheaths around neurons in the PNS
64
satellite cells
act as protective, cushioning cells in the PNS
65
form the myelin sheaths around neurons in the PNS
schwann cells
66
act as protective, cushioning cells in the PNS
satellite cells
67
neurons
nerve cells; highly specialized cells which transmit messages (nerve impulses) from one part of the body to another
68
nerve cells
neurons
69
highly specialized cells which transmit messages from one part of the body to another
neurons
70
messages transmitted by neurons
nerve impulses
71
nerve impulses
the messages transmitted by neurons
72
common features of a neuron
all have a cell body which contains the nucleus and is the metabolic center of the cell, and one or more slender processes extending from the cell body
73
cell body of a neuron
metabolic center; contains nucleus
74
process of a neuron (fibers)
vary in length from microscopic to 3 or 4 feet; longest in humans reach from lumbar region of spine to great toe; convey messages (electrical signals) either a dendrite or an axon
75
dendrites
neuron processes that convey incoming messages TOWARD the cell body; neurons may have hundreds of the branching dendrites
76
neuron processes that convey incoming messages TOWARD the cell body
dendrite
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neurons may have hundreds of these branching processes
dendrites
78
axons
neuron processes that generate nerve impulses and conduct them AWAY from the cell body; each neuron only has one axon which arises from the region on the body called the axon hillock
79
neuron processes that generate nerve impulses and conduct them AWAY from the cell body
axons
80
each neuron only has one of these processes
axon
81
axon hillock
cone-like region of the cell body where the axon rises from
82
cone-like region of the cell body where the axon rises from
axon hillock
83
branches of an axon
occasionally there is a collateral branch along the length, but at the terminal ends of axons there are hundreds to thousands of axon terminals
84
axon terminals
thousands of branches at the terminal end of axons; contain hundreds of tiny membranous sacs containing chemicals called neurotransmitters
85
thousands of branches at the terminal end of axons
axon terminals
86
contain hundreds of tiny membranous sacs containing chemicals called neurotransmitters
axon terminals
87
neurotransmitters
chemicals contained in the axon terminals; released into the extracellular space when stimulation from nerve impulses reach the axon terminals
88
chemicals contained in the axon terminals
neurotransmitters
89
released into the extracellular space when stimulation from nerve impulses reach the axon terminals
neurotransmitters
90
synaptic cleft
tiny gap separating each axon terminal from the next neuron
91
tiny gap separating each axon terminal from the next neuron
synaptic cleft
92
synapse
the region of communication between neurons; the junction of an axon terminal, the synaptic cleft, and the next neuron
93
the region of communication between neurons
synapse
94
the junction of an axon terminal, the synaptic cleft, and the next neuron
synapse
95
neurofibrils
filaments abundant in a neuron cells body which are the cytoskeleton which holds the cell shape
96
filaments abundant in a neuron cells body which are the cytoskeleton which holds the cell shape
neurofibrils
97
myelin
whitish fatty material most long nerve fibers are covered with; has a waxy appearance; protects and insulates fibers and increases transmission rate of nerve impulses
98
whitish fatty material most long nerve fibers are covered with
myelin
99
protects and insulates fibers and increases transmission rate of nerve impulses
myelin
100
how do schwann cells orient themselves on the nerve fibers?
they wrap around the axon in a jelly roll fashion end to end, look like beads on a string, to create the myelin sheath
101
they wrap around the axon in a jelly roll fashion end to end, look like beads on a string, to create the myelin sheath
schwann cells
102
the gaps between the individual schwann cells making up the myelin sheath on the axon (the space between the beads on a string)
nodes of Ranvier
103
nodes of Ranvier
the gaps between the individual schwann cells making up the myelin sheath on the axon (the space between the beads on a string)
104
neurilemma
the area of the Schwann cell cytoplasm and its exposed membrane (the outermost shell as its wrapped around the axon)
105
the area of the Schwann cell cytoplasm and its exposed membrane (the outermost shell as its wrapped around the axon)
neurilemma
106
ganglia
clusters of neuron cell bodies outside the CNS (in the PNS)
107
clusters of neuron cell bodies outside the CNS (in the PNS)
ganglia
108
myelin sheath's difference in CNS and PNS
CNS - formed by oligodendrocytes; each can coil around up to 60 different fibers; no neurilemma
PNS - formed by Schwann cells; takes many to make up one fiber's sheath; if damaged the neurilemma can stay intact & helps fiber regeneration
109
nuclei (nervous system)
the clusters cell bodies are found in in the CNS
110
the clusters cell bodies are found in in the CNS
nuclei
111
tracts
bundles of nerve fibers running through the CNS
112
bundles of nerve fibers running through the CNS
tracts
113
nerves
bundles of nerve fibers running through the PNS
114
bundles of nerve fibers running through the PNS
nerves
115
difference between nerves and tracts
both are bundles of nerve fibers
CNS - tracts
PNS - nerves
116
what do the terms white matter and gray matter refer to?
myelinated versus unmyelinated regions of the CNS
117
myelinated and unmyelinated regions of the CNS
white matter and grey matter
118
white matter
dense collections of myelinated fibers (tracts) in the CNS
119
gray matter
unmyelinated fibers and cell bodies in the CNS
120
dense collections of myelinated fibers (tracts) in the CNS
white matter
121
unmyelinated fibers and cell bodies in the CNS
gray matter
122
multiple sclerosis
myelin sheaths around the fibers are destroyed; electrical current is short-circuited
123
disease where myelin sheaths around the fibers are destroyed; electrical current is short-circuited
multiple sclerosis
124
neurons carrying impulses from sensory receptors to the CNS
sensory (afferent) neurons
125
where are the cell bodies of sensory neurons found?
in a ganglion outside the CNS
126
purpose of sensory neurons
keep us informed about what is happening both inside and outside the body
127
neurons carrying impulses from the CNS to the visera, muscles, and glands
motor (efferent) neurons
128
where are the cells bodies of motor neurons found?
always in the CNS
129
types of neurons
sensory (afferent)
motor (efferent)
interneurons (association neurons)
130
interneurons (association neurons)
connect the motor and sensory neurons in neural pathways
131
connect the motor and sensory neurons in neural pathways
interneurons (association neurons)
132
where are the cell bodies of interneurons found?
always in the CNS
133
multipolar neuron
neuron with several processes extending from cell body; most common structural type; all motor and association neurons
134
bipolar neuron
neurons with two processes - an axon and a dendrite; rare in adults, only found in special sense organs (eyes, nose) where they act in sensory processing as receptor cells
135
unipolar neurons
have a single process emerging from the cell body
