NRS 301 EXAM 3 QUESTIONS WITH COMPLETE
SOLUTIONS!!
Glia
1. Glia are typically thought of as _________ cells in the brain
2. Recently it has become clear they are fully functional participants in brain
__________ and ___________.
3. Radial cells are in the __________ and is specialized in _____________.
Answer - "support"
function and behavior
CNS
neurodevelopment
Name the 4 types of glia cells in the CNS? Answer - 1. Oligodendrocytes -
myelination in the CNS
2. Astrocytes - compose the blood brain barrier, regulates the external chemical
environment around neurons
3. Microglia - the immune cells of the CNS
4. Ependymal cells: cells that line the ventricles and spinal cord -> produce
cerebral spinal fluid (CSF)
Myelinate axons in the CNS Answer - oligodendrocytes
Compose the blood-brain barrier, regulates the external chemical environment
around neurons Answer - Astrocytes
,The immune cells of the CNS Answer - microglia
Ependymal cells are cells that line the _________ and _________ -> produce
________________ Answer - ventricles and spinal cord
cerebral spinal fluid (CSF)
Types of Glia in the PNS Answer - 1. Schwann cells - myelination in the PNS
(equivalent to oligodendrocytes in function)
a. Wraps around axons and there are multiple Schwann cells per axon
2. Satellite cells: regulate the external chemical environment in PNS (like
astrocytes in the CNS)
myelination in the PNS (equivalent to oligodendrocytes in function) Answer -
Schwann cells
regulate the external chemical environment in PNS (like astrocytes in the CNS)
2. Answer - satellite cells
___________ are primary neuronal progenitor cells that give rise to neurons
and CNS glia during development. They provide ________ for neuronal
migration Answer - Radial glia
scaffold
As the brain develops in utero, the neurons must be laid down in a specific
pattern. These cells migrate all over the place
,b. Example is the migration of neurons to develop the multiple layers of the
cortex
1. Myelin
a. Multi-layered lipid-rich membrane that insulates _________
b. _________ axon conductance
c. ~20% of the brain weight is myelin
d. Continual active process of myelination throughout _________ Answer -
axons
Increases
life: Myelination occurs throughout the life span
What are the 2 differences between oligodendrocytes and Schwann cells?
Answer - oligodendrocytes myelinate the CNS and a single oligodendrocyte
myelinates many axons while Schwann cells myelinate the PNS and only
myelinate a single axon
What are the 3 functions of myelination glia? Answer - 1. Axon stability and
support
a. Demyelination -> decreased axon conduction velocity
b. Eventually results in axon degeneration
2. Recovery from injury
a. Remyelination of axons following traumatic injury helps restore axon
function
b. Mediated by oligodendrocyte precursor cells (OPCs)
i. OPCs are partially differentiated stem cells in adult brain
ii. They eventually differentiate into mature oligodendrocytes following injury
and infection to promote remyelination
, iii. Potential targets to treat demyelinating diseases (multiple sclerosis,
leukodystrophies, etc)
3. Plasticity and Learning
a. Neuronal activity promotes oligodendrogenesis à increased myelin
b. Altered myelin thickness will affect neuron communication
c. Motor learning is associated with increased thickness of myelin sheath
The most abundant type of glia cells in the CNS are the _________. They have a
________ shape with extensive processive.
Main function is to maintain _________ Answer - astrocytes
star
homeostasis
Astrocytes: Blood-brain barrier (BBB)
1. Forms the semipermeable border that separates the __________ from the
_________, only select agents can enter
2. Basis for many drugs not being psychoactive (can't cross the BBB)
3. Astrocyte's ____________ encircle endothelial cells to support the BBB
a. Lower organisms this is the BBB
b. Higher organisms' astrocytes support the tight junctions between the
endothelial cells Answer - CNS
blood
end-feet
Astrocytes: Injury and regeneration (Injury/Ischemia)
The proliferation of astrocytes in response to neuronal damage and can result
in a glial scar is called ____________. This scar has historically been considered
SOLUTIONS!!
Glia
1. Glia are typically thought of as _________ cells in the brain
2. Recently it has become clear they are fully functional participants in brain
__________ and ___________.
3. Radial cells are in the __________ and is specialized in _____________.
Answer - "support"
function and behavior
CNS
neurodevelopment
Name the 4 types of glia cells in the CNS? Answer - 1. Oligodendrocytes -
myelination in the CNS
2. Astrocytes - compose the blood brain barrier, regulates the external chemical
environment around neurons
3. Microglia - the immune cells of the CNS
4. Ependymal cells: cells that line the ventricles and spinal cord -> produce
cerebral spinal fluid (CSF)
Myelinate axons in the CNS Answer - oligodendrocytes
Compose the blood-brain barrier, regulates the external chemical environment
around neurons Answer - Astrocytes
,The immune cells of the CNS Answer - microglia
Ependymal cells are cells that line the _________ and _________ -> produce
________________ Answer - ventricles and spinal cord
cerebral spinal fluid (CSF)
Types of Glia in the PNS Answer - 1. Schwann cells - myelination in the PNS
(equivalent to oligodendrocytes in function)
a. Wraps around axons and there are multiple Schwann cells per axon
2. Satellite cells: regulate the external chemical environment in PNS (like
astrocytes in the CNS)
myelination in the PNS (equivalent to oligodendrocytes in function) Answer -
Schwann cells
regulate the external chemical environment in PNS (like astrocytes in the CNS)
2. Answer - satellite cells
___________ are primary neuronal progenitor cells that give rise to neurons
and CNS glia during development. They provide ________ for neuronal
migration Answer - Radial glia
scaffold
As the brain develops in utero, the neurons must be laid down in a specific
pattern. These cells migrate all over the place
,b. Example is the migration of neurons to develop the multiple layers of the
cortex
1. Myelin
a. Multi-layered lipid-rich membrane that insulates _________
b. _________ axon conductance
c. ~20% of the brain weight is myelin
d. Continual active process of myelination throughout _________ Answer -
axons
Increases
life: Myelination occurs throughout the life span
What are the 2 differences between oligodendrocytes and Schwann cells?
Answer - oligodendrocytes myelinate the CNS and a single oligodendrocyte
myelinates many axons while Schwann cells myelinate the PNS and only
myelinate a single axon
What are the 3 functions of myelination glia? Answer - 1. Axon stability and
support
a. Demyelination -> decreased axon conduction velocity
b. Eventually results in axon degeneration
2. Recovery from injury
a. Remyelination of axons following traumatic injury helps restore axon
function
b. Mediated by oligodendrocyte precursor cells (OPCs)
i. OPCs are partially differentiated stem cells in adult brain
ii. They eventually differentiate into mature oligodendrocytes following injury
and infection to promote remyelination
, iii. Potential targets to treat demyelinating diseases (multiple sclerosis,
leukodystrophies, etc)
3. Plasticity and Learning
a. Neuronal activity promotes oligodendrogenesis à increased myelin
b. Altered myelin thickness will affect neuron communication
c. Motor learning is associated with increased thickness of myelin sheath
The most abundant type of glia cells in the CNS are the _________. They have a
________ shape with extensive processive.
Main function is to maintain _________ Answer - astrocytes
star
homeostasis
Astrocytes: Blood-brain barrier (BBB)
1. Forms the semipermeable border that separates the __________ from the
_________, only select agents can enter
2. Basis for many drugs not being psychoactive (can't cross the BBB)
3. Astrocyte's ____________ encircle endothelial cells to support the BBB
a. Lower organisms this is the BBB
b. Higher organisms' astrocytes support the tight junctions between the
endothelial cells Answer - CNS
blood
end-feet
Astrocytes: Injury and regeneration (Injury/Ischemia)
The proliferation of astrocytes in response to neuronal damage and can result
in a glial scar is called ____________. This scar has historically been considered
