Nervous tissue: quilt Flashcards
(219 cards)
1
Q
Euchromatin
A
lightly packed DNA
-often but not always under active transcription
2
Q
Heterochromatin
A
darker staining
-dense DNA found in the nucleus of cells
3
Q
T or F: Neuron nuclei can contain multiple nucleolus.
A
True
4
Q
Nissl Substance
A
RER cisternae + free ribosomes in alternating pattern
5
Q
Do Nissl substances stain acidophilic or basophilic?
A
Basophilic
6
Q
Lipofuscin
A
product of lysosomes, brown pigment of undigested material that typically increases with age
7
Q
T or F: The axon hillock contains Nissl substance.
A
false
8
Q
Neurotubules
A
microtubules located in the neuron
9
Q
T or F: Golgi can be extremely large in the cell body of neurons.
A
true
10
Q
Neurofibrils
A
Clusters of neurofilaments
11
Q
Neurofilaments
A
neuron-specific intermediate filaments
12
Q
Actin
A
Microfilament commonly seen in the neural cell body
13
Q
Two other names for a neuron cell body
A
perikaryon and soma
14
Q
T or F: Neurons can divide
A
False
15
Q
T or F: Since neurons can’t divide, the cellular components are also never regenerated.
A
False
16
Q
Synapse
A
Pre-Synaptic terminal + Synaptic Cleft + Post-synaptic terminal
17
Q
End Bulb
A
another name for terminal end of axon
18
Q
Synaptic Vesicles
A
located at the axon terminal
-contain neurotransmitters
19
Q
Dendrites
A
part of neuron that is involved in receptor processes
-receives stimuli from other neurons or extracellular environment
20
Q
T or F: Dendrites are tapered because their diameter decreases as you leave the cell body and branch
A
True
21
Q
T or F: Dendrites are almost Never myelinated
A
True
22
Q
Dendrites branch off at __ angles.
A
acute
23
Q
T or F: Golgi cannot extend into the dendrites
A
False
24
Q
T or F: Dendrites contain ribosomes
A
True
25
T or F: MT in the dendrites have no particular arrangement
False
26
How are MT in the dendrites arranged?
evenly spaced
27
In what way do dendrites function (input)?
dimmer switch
28
What is an example of a location in the body where neurons do not contain axons?
retina
29
T or F: Axons maintain a constant diameter
true
30
Which have a larger diameter, dendrites or axons?
dendrites
31
Which tends to branch more frequently, dendrites or axons?
dendrites
32
T or F: Axons can be myelinated.
true
33
Axons branch off at __ angles.
obtuse
34
How does the diameter of axon branches compare to the rest of the axon? (larger, smaller or same)
same
35
T or F: Axons never contain ribosomes
True
36
T or F: Axon neurofilaments and MT have an evenly spaced arrangement
False
37
The action potential of axons is ___
all or none
38
Can axons contain Nissl bodies or golgi?
no
39
How frequently do axons contain ribosomes?
never
40
Dendritic spines
mushroom-shaped structures connected to dendritic shaft
- involved in "Plastic" changes o the brain
- adaptation, learning, memory
41
What is the function of dendritic spines?
increase receptive area
42
on what order are dendritic spines present in the human cerebral cortex?
10^14
43
Hw many ribosomes are present in dendritic spines?
None
44
T or F: Dendritic spines are where most synapses impinging on neurons are made.
true
45
T or F: Dendritic spines are static structures.
false
46
T or F: SER and filamentous proteins extend into the dendritic spines.
true
47
Bipolar neuron
neuron type most often associated with receptors for special senses
48
T or F: Bipolar neurons are commonly found in the body.
false
49
Bipolar neurons contain _ axon and _ dendrite
1, 1
50
Which type of neurons are most common?
multipolar
51
Multipolar neurons
neurons containing more than 2 processes
52
Pseudounipolar neuron
Neuron type in which a T shape is formed
- neurons in which stimuli travel from dendrites directly to axon terminal w/out passing through cell body
- neuron type found in sensory neurons and ganglia (DRG)
- centrally located nucleus, single process, and round perikarya
53
Synapse
Sites of functional contact between neurons and other neurons or effector cells
-convert electrical impulse into a chemical sign via neurotransmitter
54
T orF: Neurotransmitter's can be excitatory or inhibitory
True
55
What holds the pre and post synaptic terminals approximate in the synaptic cleft?
filamentous proteins
56
Neurotransmitters
Released into synaptic cleft and bind receptors on post-synaptic membrane
-responsible for unidirectional transmission of nerve impulses
57
dendrodendritic
classification of synapse between dendrites and other dendrites
58
axosomatic
classification of synapse located at the soma/cell body
59
axodendritic
classification of synapse on dendrite shaft or spine
60
Axoaxonic
Classification of synapse on axons
61
What percent of chemical synapses involve no reuptake of neurotransmitters?
20
62
T or F: 99.9% of synapses are chemical
true
63
What percent of chemical synapses involve the reuptake of neurotransmitter?
80%
64
T or F: Electrical synapses require neurotransmitters.
False
65
Acetylcholine (Ach) is an example of chemical ____ of neurotransmitter.
without reuptake
66
Epinephrine, serotonin and dopamine are examples of chemical synapses that ___ neurotransmitters.
reuptake
67
Cocaine inhibits the reuptake of what in the pleasure centers of the brain?
Dopamine and serotonin
68
What does electrical synapses use instead of neurotransmitters?
ions
69
Acetylcholine
very small synaptic vesicle that is clear on micrograph
70
norepinephrine
synaptic vesicle with small dot in center
71
inhibitory
synaptic vesicle with a tendency to fallen out
| -contains GABA
72
Serotonin (5HT)
large synaptic vesicle with a very dense core
73
GABA
most abundant neurotransmitter in CNS
74
Glutamate
most abundant excitatory neurotransmitter in CNS
75
Neurotransmitters associated with pleasure centers of the brain?
dopamine and serotonin
76
Neurotransmitter involved in pain transmission?
substance P
77
non-directed synapses
synapses without distinct postsynaptic targets
78
What is the ratio of glia too neurons?
10:1
79
Glia (neuroglia)
cells that offer protection and support for neurons
80
T or F: there is a slow, constant turnover of glia
true
81
T or F: there is true connective tissue in the CNS
false
82
Astrocytes
- glia with a large morphological to function diversity
- have perivascular end feet covering blood vessels
- help create blood brain barrier (BBB)
- Most numerous glia cells
- cofine Neurotransmitters to the synaptic cleft
83
Fibrous
astrocyte subtype found in white matter
| -contains few, long cellular processes
84
protoplasmic
astrocyte subtype found in gray matter
| -contains many, short-branched processes
85
Bergmann glia
astrocyte unique to the cerebellum
86
T or F: GFAP and glutamate synthetase are common markers of astrocytes
True
87
astrocytomas
tumors of astrocyte cells
88
T or F: Astrocyte processes can extend up to 100 micrometers
True
89
Which type of glia are involved in the reaction to injury?
astrocytes
90
Oligodendrocytes
myelin producing cells of the CNS
91
oligodendrocytomas
tumors of oligodendrocytes
92
T or F: Oligodendrocytes produce myelin for only one axon
False
93
Schwann cells
myelin producing cells of the PNS
94
T or F: All axons in PNS have myelin about them.
true
95
microglia
glia with phagocytic properties
| -associated with immune response/part of the immune system
96
what is the embryonic origin of microglia?
mesoderm
97
T or F: All glia originate from ectodermal tissue
false
98
What creates microglia?
blood monocytes
99
Microglia are normally found near ___.
blood vessels
100
Microglia can act as ___.
antigen presenting cells
101
T or F: Microglia are normally active so they can respond to injury or pathogen invasion quickly.
false
102
What do microglia release in order to attract T cells to nearby injury?
cytokines
103
What do microglia release in order to activate nearby microglia?
interferon gamma
104
ependymal
cuboidal/columnar epithelia glia cells that line the ventricles and central canal of the Brian and spinal cord
105
Which glia cell type is often ciliated to facilitate CSF movement?
ependymal
106
What is commonly used marker for ependymal glia?
vimentin
107
Which type of glia uses microvilli to sample/monitor CSF?
ependymal
108
The CSN contains which two structures?
brain and spinal cord
109
What makes white matter white?
myelin
110
T or F: white matter contains few to no neuron cell bodies
true
111
__ matter contains many myelinated axons and lots of glia.
white matter
112
T or F: The brain contains white matter outside and gray matter inside.
False
113
The inner structure of the spinal are composed of __ matter.
gray
114
Nucleus
collection of the neurons in CNS
115
ganglia
collection of neurons in PNS
116
Which contains more blood vessels? (white or gray matter)
gray
117
PNS
cell bodies and nerve process outside the brain and spinal cord
118
Gray matter
Network of cell bodies, unmyelinated axons and dendrites (AKA neuropil) and glia
119
Autonomic nervous system
Consists of the CNS and PNS
| -related to control of smooth muscle, secretion and modulation of cardiac muscle
120
Sympathetic nervous system
fight or flight response of the autonomic nervous system
121
Parasympathetic nervous system
Mate and relate response of the autonomic system
122
Spinal nerve
location where Doral and ventral roots meet temporarily
123
T or F: sympathetic ganglia are usually located in the organ of innervation
False
124
T or F: Sympathetic ganglia are generally located near the spinal column.
true
125
Afferent
another name for the input units of the reflex arc
126
efferent
another name for the output units of the reflex arc
127
Sensory ganglia is found near the __.
Spinal column
128
Satellite cells
similar to Schwann cell but produce no myelin
129
T or F: Satellite cells form a distinct layer and uniformly surround neurons
True
130
T or F: Autonomic motor ganglia is an example of a primary motor neuron.
False
131
Do sympathetic ganglia live in the head?
no
132
Which typically has fewer neurons? (sympathetic or parasympathetic)
parasympathetic
133
Which contains multipolar neurons? (sympathetic or parasympathetic)
sympathetic
134
T or F: The brain and spinal cord are solid structures
false
135
T or F: Only the spinal cord is lined with ependymal cells, the Brian is not.
False
136
T or F: CSF is not produced by the ventricles itself
true
137
What structure within the ventricles produces CSF?
choroid plexus
138
choroid
made up of dilated, fenestrated (leaky) capillaries enveloped in invaginated folds of Pia mater
139
CSF
produced continually by choroid plexus
| -circulated through ventricles, central canan, and subarachnoid space
140
Dura Mater
tough, relative thick sheet of dense connective tissue
| -very rich in nerve endings
141
Arachnoid
delicate sheet of connective tissue coated beneath dura mater
142
Pia mater
very delicate and thin layer of connective tissue
| -only layer directly adhered to brain or spinal cord
143
What is the subarachnoid space filled with?
CSF
144
Meningitis
Inflammation of the meninges (mostly arachnoid and pis)
145
Epineurium
fibrous coat of dense CT found in the PNS
146
Perineurium
flattened epithelial-like cells in PNS
- joined at edges via tight junctions
- analogous to arachnoid
147
endoneurium
thin layer of reticular fibers
| -produced by Schwann cells in PNS
148
Nerve fascilicus
Bundle of axons in the PNS
149
Which CT covering in the PNS directly surround individual axons?
endoneurium
150
Which CT covering in the PNS surrounds and binds together many fascicles?
epineurium
151
T or F: Unmyelinated axons still have Schwann cells attached to them
true
152
Perineural epithelium
1-2 layers of CT in PNS consisting of squamous-like cells
153
Ependymal
cell type that lines hollow space in ventricles and central canal filled with CSF
154
T or F: Ependyma cells are not ciliated
False
155
Choroid cell
cuboidal epithelium cell that secretes CSF
| -has cilia and microvilli
156
T or F: increasing the axon diameter increases the conduction time.
False
157
Which axons conduct signals faster? (myelinated or unmyelinated)
myelinated
158
Myelin
electrical insulator on some axons
159
T or F: Voltage reversal is inhibited by myelin at the Nodes of Ranvier
False
160
In myelinated axons, what is the term of how the voltage reversal jumps from node to node?
saltatory conduction
161
T or F: Voltage sensitive Na+ and K+ channels are located at the Nodes of Ranvier.
True
162
T or F: All axons have Nodes of Ranvier
False
163
The conduction velocity vs diameter graph for unmyelinated axons can be best described as ___
linear
164
T or F: In the PNS, all axons are surround by Schwann cells
True
165
PNS nerves that are surround by the body of Schwann cut have no myelin wrapping or Nodes of Ranvier are called what?
Unmyelinated
166
T or F: In myelinated PNS nerves, the Schwann cells cover multiple axons
False
167
How many axons does on Schwann cell cover in myelinated PNS nerves?
One (technically 1 segment of 1 axon)
168
Which type of PNS nerves have abutted together Schwann cells in order to form a continuous sheath?
unmyelinated
169
In the CNS, myelinated axons re surrounded by ____.
Oligodendrocytes
170
How many axons can on oligodendrocyte myelinated?
5-10
171
T or F: Unmyelinated axons in the CNS are still surrounded by oligodendrocytes.
false
172
What glia cell type can surround unmyelinated axons in the CNS?
astrocytes
173
Which glia type helps control the ionic and chemical environment in the CNS?
astrocytes
174
T or F: Astrocytes have a role in synaptic activity.
True
175
Astrocytes form the ___ barrier.
pia-glia barrier
176
Which endocytotic method does astrocytes use to remove excess neurotransmitters?
pinocytosis
177
What part of astrocytes regulate transport?
end feet
178
Which cell junction type links endothelial cells to form the anatomical BBB?
zonula occludens
179
T or F: The blood brain barrier does not contain a basement membrane
false
180
What surrounds the BBB?
astrocyte end feet
181
T or F: Lipid soluble molecules like O2, CO2, and EtOH cross the BBB easily.
True
182
Which endocytotic method transports macromolecules across the BBB?
Receptor mediated
183
Axoplasmic transport
movement of material in the neuron
184
Which pathway of axoplasmic transport is followed by toxins and viruses entering the CNS?
retrograde
185
Which axoplasmic transport method moves material away from the cell body?
anterograde
186
In which direction (anatomically speaking) does retrograde axoplasmic transport occur?
toward cell body
187
T or F: In retrograde axoplasmic transport, there is only a fast type, there is no slow movement.
True
188
What is the velocity of "fast" anterograde transport?
20-400 mm/day
189
What is the velocity of "slow" anterograde transport?
0.6-4mm/day
190
What does fast anterograde transport move?
organelles and molecules
191
What does slow anterograde transport move?
cytoskeletal and axolemma components
192
T or F: Anterograde axoplasmic transport involves kinesin.
true
193
T or F: Retrograde axoplasmic transport utilizes tubulin and actin
false
194
What MT associated protein does retrograde axoplasmic transport involve?
dynein
195
Which two cytoskeletal does slow anterograde transport involve?
tubulin and actin
196
Which pathway does Herpies and Rabies use to invade the CNS?
Retrograde
197
Can mammalian neurons divid?
no
198
How often do mammalian neurons divid?
never
199
T or F: In the case of injury, neurons can divide to regenerated nervosa system functions.
false
200
T or F: Nervous tissue regeneration represents a permanent loss.
true
201
T or F: Neuronal process are replaceable through growth and synthetic activity of the soma in a very narrow window of time.
true
202
What limits possible regrowth of nervous tissue in the CNS?
glial scarring
203
T or F: PNS fibers can regenerate if the soma isn't destroyed and severed fibers are well approximated.
true
204
Chromatolysis
cellular adema and loss of Nissl substance
205
Secondary degeneration (wallerian)
```
anterograde degeneration (axon to myelin sheath)
-degenerate and invaded by macrophages
```
206
What what rate does axonal sprouting (neurites) occur?
.5-3 mm/day
207
beta-amyloid plaques
aggregated misfolded proteins implicated in Alzheimer disease
208
Depression
a multifaceted disease with one component thought to involve the reuptake of serotonin and not epinephrine
209
T or F: SSRI's and SNRI's slow down the reuptake of serotonin in depressed individuals.
true
210
MAOI's
an "Old school" treatment for depression containing monoamine oxidase that rapidly degrades norepinephrine
211
Huntington Chorea
Fatal hereditary disease though to be the loss of GABA producing neurons
212
When (in patients lifetime) does Huntington Chorea typically become evident?
30-40s
213
Parkinson's Disease
disease characterized by the loss of dopamine producing neurons in the substantial nigra and basal ganglia
214
T or F: Dopamine is used in pathways coordinating smooth, focused movements.
true
215
What is the name of the Parkinson's disease hallmark resting tremor?
pill rolling tremor
216
What hallmark of Parkinsons disease describes the loss of smooth movements?
cogwheel rigidity
217
What is a common Parkinsons disease treatment, a dopamine precursor that can cross the BBB?
L-Dopa
218
Fibrous astrocytomas
tumors arising from fibrous astrocytes
219
T or F: 80% of adult primary brain tumors can be classified as fibrous astroctyomas
true
