Chapter 9: Nerve Cells Flashcards
(142 cards)
1
Q
what cells and structures compose the white matter of the CNS?
A
- axons
- dendrites
- neuroglia
2
Q
what cells and structures compose the gray matter of the CNS?
A
- neuron cell bodies
- neuroglia
3
Q
describe the nucleus of neurons…
A
prominent nuclei and nucleolus
4
Q
neurons are abundant in..
A
nissl substance
5
Q
neurons have a well developed
A
Golgi
6
Q
neurons are NOT
A
mitotic
7
Q
neurons are known for the production of
A
neurotransmitters
8
Q
how are neurons specialized for electrical transmission?
A
by myelin sheaths around the axons
9
Q
what are the 5 types of neuroglia?
A
- oligodendrocytes
- astrocytes
- ependymal cells
- microglia
- schwann cells
10
Q
what are the function of oligodendrocytes?
A
- form myelin sheaths in the CNS
- allows for saltatory conductions of action potentials
11
Q
function of actrocytes
A
- controls extracellular movement by removing excess neurotransmitters
12
Q
astrocytes communicate via
A
jap junctions
13
Q
ependymal cells line what part of the brain and spinal cord?
A
ventricles
14
Q
describe the histology of ependymal cells
A
cubodial w/ microvilli
15
Q
what is the function of ependymal cells?
A
to produce CSF in the choroid plexus
16
Q
microglia are ________ cells
A
phagocytic
17
Q
microglia are derived from
A
monocytes
18
Q
what is the function of Schwann cells
A
to produce the myelin sheath
forming nodes of Ranvier
19
Q
Schwann cells are aka
A
neurolemmocytes
20
Q
what protein is used as an immunohistochemical marker for gial cells?
A
GFAP
21
Q
which cells comprise the BBB?
A
endothelial cells w/ tight junctions
astrocyte processes
22
Q
what is the function of the BBB?
A
neural protection by restricting passage of molecules & pathogens
23
Q
what are the 3 layers of CT in peripheral nerves?
A
- epineurium
- perineurium
- endoneurium
24
Q
the epineurium is the
A
external layer of dense CT
25
the perineurium...
surrounds each fascicle
26
the endoneurium surrounds each
nerve fiber
27
which of the 3 layer in CT of peripheral nerves contain reticular fibers
endoneurium
28
the reticular fibers of the endoneurium are made by
Schwann Cells
29
what are the 3 meningeal layers?
1. Dura mater
2. Arachnoid
3. Pia Mater
30
dura mater can be described as
dense regular CT
31
the arachnoid layer can be described as being
spider-like w/ a subarachnoid space filled w/ CSF
32
the pia mater is the
innermost meningeal layer
33
the pia mater is contacted by
glial cells
34
what are the necessary conditions for the successful repair of nerve damage in the PNS?
- soma not destroyed
- proper reconnection of axon the Schwann cells
35
describe the process of nerve regeneration in the PNS
injury -> distal degradation -> Schwann cell proliferation
36
Poliomyelitis occurs when
a virus enters the motor neurons in the ventral horn of the spinal cord
37
the virus in poliomyelitis kills ___________ causing ___________.
- neurons
- paralysis
38
glioma is resistant to
chemotherapeutic agents
39
what is the average survival rate of patients w/ glioma
about 3 months
40
alzheimer's can be described as a
neurodegenerative disease
41
what are the 2 characteristic features of Alzheimer's?
1. Amyloid plaques
2. NFTs
42
how are amyloid beta plaques formed?
from the proteolysis of APP
| APP: amyloid precursoe protein
43
how are NFTs formed?
tau protein forming insoluble plaques
44
the insoluble plaques in NFTs interfere w/
cytoskeletal microtubules
45
what are the 3 functions of nervous tissue?
1. reception
2. processing electrical/chemical signals
3. transmission of electrical/chemical
46
what are the 2 divisions of the NS?
- functional
- anatomical
47
the functional division of the NS composes what 2 subcategories?
1. autonomic
2. voluntary
48
the anatomical division of the NS composes what 2 subcategories?
1. CNS
2. PNS
49
what types of cells are found in gray matter?
- neuron cell bodies
- neuroglia
50
what types of ells are found in the white matter?
- axons/dendrites
- neuroglia
51
neurons are known for their ____________ and propagation of __________.
- irritability
- impulses
52
what is the characteristic appearance of neurons?
- large soma
- prominent nucleus & nucleolus
53
why do neurons typically have a large cell body?
to be able to produce adequate neurotransmitters
54
neurotransmitters are...
small peptides
55
what are the 2 cell processes in neurons?
1. axons
2. dendrites
56
axons are used to
conduct signals
57
axons can be very
long
58
why are there a lot of dendrites?
to increase surface area
59
what is the function of dendrites?
to receive signals
60
there is an abundance of what organelle in neurons?
RER
- basophilic
61
what organelle is "well-developed" in neurons?
Golgi apparatus
62
neurons are...
NON-MITOTIC
63
what protein is typically visible in aged neurons?
lipofuchsin
64
describe lipofushin
- brownish pigment in secondary lysosomes w/ digested material
65
neurons communicate with other neurons at
synapses
66
what do neurons use for chemical signaling?
neurotransmitters
67
what are the special stains used on neurons?
- nissl stain
- osmium stain
- silver stain
68
what are the 3 main types of neurons?
1. bipolar
2. multipolar
3. pseudounipolar
69
how many axons and dendrites are found in bipolar neurons?
- 1 axon
- 1 dendrite
70
where are the places that bipolar neurons are found?
- retina
- olfactory cells
- cochlear ganglia
- vestibular ganglia
71
what is the distribution of axons and dendrites in multipolar neurons?
- 1 axon
- multiple dendrites
72
multipolar neurons are most commonly found in the
CNS
73
describe pseudounipolar neurons
soma w/ single process that branches
74
in pseudounipolar neurons the process immediately branches into
- dorsal root ganglia
- cranial ganglia
75
is the soma of the CNS located in the gray or white matter?
gray
76
the soma in the PNS is located in the
- ganglia
- specialized sensory regions
77
define synapses
points of contact between neurons
78
what is released at synapses?
neurotransmitters
79
synapses can be either
excitatory or inhibitory
80
synapses receive input from the
environment and other neurons
81
synapses transmit information to
other neurons and effector cells
82
list 5 examples of neuroglia
1. oligodendrocytes
2. astrocytes
3. ependymal cells
4. micorglia
5. Schwann cells
83
where are Schwann cells found?
in the PNS
84
what neuroglia is found in the CNS?
- oligodendrocytes
- microglia
- ependymal cells
- astrocytes
85
In the CNS, glial cells are more numerous than ___________
neurons
86
neuroglia provide ___________ & _____________ support for neurons
- structural
- nutritional
87
most neurons will die w/o
neuroglia
88
neuroglia are NOT capable of transmitting ____________ or forming _______________ but are capable of ___________.
- action potentials
- synapses
- mitosis
89
what is the specific marker that is expressed by neuroglia and can be used for immunohistochemical staining?
glial fibrillary acidic protein (GFAP)
90
oligodendrocytes form the _________ ____________ around axons in the __________.
- myelin sheath
- CNS
91
the myelin sheath allows for ________________ conduction of action potentials
saltatory
92
what is the most numerous type of neuroglia?
astrocytes
93
what shape do astrocytes exhibit?
a star shape
94
astrocytes are necessary for controlling
- extracellular movement
95
how do astrocytes control extracellular movements?
- removing neurotransmitters
- releasing metabolites
96
astrocytes communicate via
gap junctions
97
astrocytes have 'end feet' that envelop ____________ in the _________ as a part of the _______.
- capillaries
- CNS
- BBB
98
the BBB is
neuroprotective
99
The BBB is composed of
endothelial cells & astrocyte processes
100
the BBB restricts the passage of...
molecules & pathogens into brain tissue
101
ependymal cells line the ventricles of the
brain & spinal cord central canal
102
ependymal cells are typically
cuboidal w/microvilli
103
ependymal cells produce
CSF in the choroid plexus
104
microglia are
phagocytic cells
105
describe microglia
short, branched processes
106
microglia also contribute to the brain's
immune protection
107
Schwann cells are aka
neurolemmocytes
108
Schwann cells form the myelin sheath of axons in the
PNS
109
what are the spaces between adjacent Schwann cells known as?
nodes of Ranvier
110
peripheral nerves are large bundles of
axons (nerve fibers)
111
what are the 3 layers of connective tissue in the PNS?
1. epineurium
2. perineurium
3. endoneurium
112
the epineurium is the external layer composed of
dense CT
113
the perineurium surrounds the
bundles of fibers (fascicles)
114
the endoneurium surrounds each
nerve fiber
115
the endoneurium contains some
reticular fibers
116
the endoneurium is made by
Schwann cells
117
the CNS is protected and cushioned by the...
1. skull
2. vertebral column
3. meninges
118
what are the 3 layers of the meninges?
1. dura mater
2. arachnoid
3. pia mater
119
the dura mater is composed of
dense regular CT
120
the arachnoid meninge can be described as
- spider-like w/ a space beneath it filled by CSF
121
the pia mater is the __________ meningeal layer
innermost
122
processes of glial cells contact what layer of the meninges?
the pia mater
123
what cushions the brain and spinal cord?
CSF
124
CSF is produced by
ependymal cells in the 3&4th ventricles
125
CSF is high in ___________ and low in __________
- glucose
- protein
126
the CSF has no other cells other than the occasional
lymphocyte
127
CSF is reabsorbed by
arachnoid into venous system
128
peripheral nerves can regenerate if the soma is not
destroyed
129
upon injury what portion of the axon degenerates?
distal portion
130
axon degeneration leads to the proliferation of
Schwann cells
131
the proximal portion of the axon can regenerate if it connects to the
proper Schwann cell
132
poliomyelitis contains a virus that enters the...
motor neurons of ventral horns of the SC
133
with poliomyelitis paralysis can occur if
the virus kills neurons
134
post-polio syndrome leads with neurological issues such as
- limb weakness
- tremors
- issues speaking/ swallowing
135
what is a glioma?
a tumor arising from glial cells
136
gliomas are resistant to many
chemotherapeutic agents
137
alzheimer's is a neurodegenerative disease the affects
- memory
- coordination
- ppl's ability to function
138
AD is histologically characterized by
- amyloid plaques
- NFTs
139
amyloid plaques are
extracellular deposits of beta-amyloid
140
how are the plaques made?
from the abnormal proteolysis of APP
| APP: amyloid precursor protein
141
tau under normal conditions is a
microtubule stabilizing protein
142
tau forms abnormal "clumps" that interfere w/
cytoskeleton's microtubules
