CNS Flashcards
(120 cards)
1
Q
singular meninx is composed of
A
specialized epithelial cells (meningothelial cells)
2
Q
meninges are supported by
A
connective tissue
3
Q
meninges have a — function
A
protection
4
Q
the meninges are confined to
A
outlet layer of brain and cord in CNS
5
Q
dura mater
A
outermost layer
thick layer of dense connective tissue, internally lined by mesothelium
6
Q
dura in the cranium
A
fuses with the periosteum of the skull
7
Q
dura in the spinal cord
A
dura surrounded by epidural space
8
Q
subdural space
A
separates the dura from underlying arachnoid mater
9
Q
underlying subarachnoid space is lined by
A
flattened mesothelial cells
10
Q
subarachnoid space separates the arachnoid from the Pia mater, subarachnoid space contains
A
CSF
11
Q
subarachnoid space is continuous with
A
ventricles of the brain
12
Q
pia mater is highy
A
vascular
13
Q
pia + arachnoid
A
leptomeninges
14
Q
denticulate ligamanets
A
support cord, extend from pia, anchor cord to arachnoids, dura, and periosteum
15
Q
neurons in the CNS are derived from
A
neuroectodermal cells of the neural tube
16
Q
brain and cord contain
A
gray and white matter
17
Q
peripheral gray matter contains
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neuron cell bodies, dendrites, and axons
18
Q
central white matter contains
A
mostly myelinated axons
19
Q
neuroglia/neuroglial cells
A
large number of support cells in the CNS
20
Q
neuroglia are highlight branched and provide
A
structural and metabolic support for neurons
aid in tissue repair following injury
21
Q
oligodendrocytes
A
CNS equivalent of Schwann cells, elaborate myelin sheaths
22
Q
astrocytes
A
most highly branched, largest neuroglia cells
23
Q
microglia
A
phagocytic, fixed tissue macrophage; part of monocyte-macrophage lineage; smallest neuroglia cells; originally mesodermal, have immune function
24
Q
ependymal cells
A
cuboidal epithelium singing ventricles and central canal of spinal cord
25
ependymal cells are frequently
ciliated, microvilli for reabsorption of CSF
26
CSF is secreted by the
choroid plexus
27
choroid plexus
vascular structure arising from walls fo ventricle in brain
28
modified --- cells secrete CSF
ependymal cells of the choroid plexus
29
cerebrum is also known as the
cerebral cortex
30
in mammals, neocortex evolved to include
sensory, motor, and association areas
31
in humans --% of the cortex is neocortex
90%
32
cerebrum is grossly organized into
folds or gyri
33
cerebral cortex is composed of --- --- peripherally
gray matter
34
nuclei
Clusters of neuron cell bodies form small islands of gray matter in cerebrum & cerebellum
35
Neuroglial cells in gray matter include (2)
astrocytes and microglial cells
36
Deep to cortex is subcortical
white matter (medulla)
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white matter contains mostly
myelinated axons surrounded by oligodendrocytes
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Axons leading in & out of gray matter also grouped in bundles called
tracts
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Histologically, neurons of neocortex divided into --- morphological categories
five
40
Anatomically, divided into ---layers, designated with Roman numerals I-VI, from superficial to deep
six
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functionally, arranged into
vertical columns or units
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cortical neurons (5)
```
pyramidal cells
stellate cells
cells of martinotti
fusiform cells
horizontal cells of cajal
```
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pyramidal cells
pyramid-shaped neurons with long, slender axons, varying in size from small to large
44
Beta cells
largest pyramidal cells, include upper Moto neurons in the motor cortex
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stellate cells
mall star-shaped neurons with short axons & dendrites
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cells of martinotti
small neurons with long, horizontal axons
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fusiform cells
vertically oriented, spindle-shaped neurons with vertical axons
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horizontal cells of cajal
horizontally oriented, spindle-shaped neurons with horizontal axons
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least common cortical neurons
horizontal cells of canal
| found only in the superficial layer
50
first layer of the neocortex
plexiform (molecular) layer—most superficial layer; contains mostly dendrites & axons of cortical neurons
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second layer of the neocortex
outer granular layer—contains large #’s of small pyramidal & stellate cells
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third layer of the neocortex
pyramidal cell layer—larger cells located deeper in layer; Martinotti cells also present
53
fourth layer of the neocortex
inner granular layer—densely packed stellate cells
54
fifth layer of the neocortex
ganglionic layer—contains large pyramidal cells, stellate cells & cells of Martinotti
55
sixth layer of the neocortex
multiform cell layer—contains small pyramidal cells, cells of Martinotti, stellate cells & fusiform cells
56
cerebellum coordinates (3)
muscular activity, posture, & equilibrium
57
cerebellum is grossly organized into
folds, or folia, with central medullaof whitematter, contains mostly oligodendrocytes & myelinated axons
58
outer cerebellar cortex has - layers
2
59
2 layers of the outer cerebellar cortex
Outer molecularlayer
| Inner granularlayer
60
Outer molecularlayer
contains few neurons & large #’s of unmyelinated axons
61
Inner granularlayer
highly cellular, very basophilicContains large # of neuroglial cells & small neurons called granulecells
62
Molecular & granular layers separated by single layer of large neurons called
Purkinje cells
63
Purkinje cells
specialized neurons, function in coordination & equilibrium
64
spinal cord has a similar structure throughout, with a prominent
ventral median fissure
65
central canal contains
CSF
66
central canal is lined by
ependymal cells
67
central canal is continuous with
ventricles of the brain
68
Unlike brain, gray matter of the spinal cord is located ---, white matter ---
centrally
| peripherally
69
anatomy of the spinal cord
2 dorsal horns & 2 ventral horns connected by thin central commissure
70
what do dorsal horns of the spinal cord contain?
afferent, sensory nerve tracts
71
what do dorsal nerve roots form
lateral extensions of dorsal horns of gray matter
72
central bodies of somatic sensory neurons lie in the
dorsal root ganglia of spinal nerves
73
ventral horns contain
efferent (motor) n cell bodies to innervate skeletal muscle
74
surrounding white matter of spinal cord contains (2)
ascending and descending fiber tracts
75
columns
ascending and descending fiber tracts
76
spinal cord contains mostly --- axons
myelinated
77
spinal cord contains mostly myelinated axons which carry
sensory and motor data
78
in the PNS, connective tissue scar and Schwann cells form bridge between
ends of nerve
79
if the gap is not too big, what is possible?
regeneration of the axon
80
3 steps to regeneration of axons
1: Schwann cells multiply to physically bridge the gap
2: nerve axon sprouts neurites from proximal stump
3: neurites grow into distal stump; contact reestablishes function
81
if damage is too old or severe, the axon may need to
regrow its entire length
82
how long can response to injury take?
weeks to months
83
anterograde (wallerian) degeneration
if portion of axon distal to point of injury degenerates
84
due to interruption of
axonal transport (nutrient synthesis occurs in cell body, transport down axon)
85
cell body of an injured neuron also swells, becomes
brightly eosinophilic, loses nissl substance
86
chromatolysis
loss of nissl substance
87
what happens if injury is severe?
results in retrograde degeneration and death of cell body
88
in the CNS, oligodendrocytes are less efficient than Schwann cells; instead,
neuroglia cells multiply
89
scar tissue proliferation from glial cells prevents
regeneration
90
how does scar tissue prevent regeneration?
physically blocks contract between body and axon
91
neurons terminally differentiated (Go) o they are unable to be
replaced
92
ALS
amyotrophic lateral sclerosis
93
ALS is also known as
lou gehrigs disease
94
ALS
due to death of motor neurons controlling voluntary mm
95
meningitis
inflammation of the meninges
96
meningitis may be
bacterial or viral
97
encephalitis
inflammation of the brain
98
myelitis
inflammation of the spinal cord
99
encephalomyelitis
brain and cord
100
meningoencephalitis
meninges and brain
101
symptoms/severity vary from
mild (headaches) to paralysis, debilitation and death
102
viral meningitis generally
transient lymphocytic inflitrate
103
bacterial meningitis ex (2)
meningococcus, streotococcus
104
bacterial meningitis can result in
neutrophilic infiltrate and may be life threatening
105
polo
poliovirus affects alpha-motor neurons of the ventral horn of spinal cord
106
poliomyelitis
lower motor neuron paralysis and subsequent mm atrophy
107
how was poliomyelitis eradicated?
invention of Salk vaccine
108
Parkinson's disease
neurodegenerative disease characterized by muscular tremor due to death of neurons in substantial nigra
109
Parkinson's disease decrease production of
dopamine in the brain
110
treatment of Parkinson's involves administration of
l dopa
111
l dopa
dopamine precursor
112
Alzheimers disease
form of dementia characterized by neural plaques and fibrillary tangles within the cortex
113
multiple sclerosis (MS)
an autoimmune, inflammatory, demyelinating disease of the CNS
114
in MS, antibodies destory
myelin sheaths around axons
115
destruction of myelin sheaths results in
plaque formation
116
who does MS usually affect?
women between 20-40 years of age
117
symptoms of MS vary with (2)
location of affected neurons and degree of degeneration
118
MS is often multiple episodes with
partial resolution in between
119
Guillain barre syndrome
immune mediated demyelination in PNS
120
Gillian barre is often imitated by infection, leading to
progressive weakness in peripheral mm
