BIO 264 EXAM 3 COMPREHENSIVE
QUESTIONS AND SOLUTIONS
◉ glial cells
Answer: the supporting units
◉ central nervous system (CNS)
Answer: The CNS consists of neurons associated with central
processing and which are located in the brain and spinal cord. if
the entire structure of the neuron is contained within the brain
and/or spinal cord, the neuron would be considered part of the
CNS.
◉ peripheral nervous system (PNS)
Answer: The peripheral nervous system (PNS) consists of neurons
associated with sensory input (afferent) and motor output
(efferent), and functions to connect the central nervous system to
all other parts of the body. if any part of the neuronal structure is
located outside of the brain and/or spinal cord the neuron would
be considered part of the PNS
◉ Oligodendrocytes
Answer: a glial cell similar to an astrocyte but with fewer
protuberances, concerned with the production of myelin in the
central nervous system.
,◉ What four types of glial cells are in the CNS?
Answer: the astrocyte, the oligodendrocyte, the ependymal, and
the microglial cell.
◉ astrocyte
Answer: Astrocytes have an enormous amount of processes that
wrap around blood vessels and neurons. Because of this
arrangement, astrocytes are ideally positioned to control and
modify the extracellular environment around neurons. Most of the
functions of the astrocyte are attributed to controlling this
environment
◉ Glycogen storage (Astrocyte characteristic)
Answer: Astrocytes store all the glycogen present in the CNS. This
glycogen is used to help meet the high metabolic needs of the CNS.
The main source is blood glucose, but glycogen levels can sustain
the need for 5 to 10 min.
◉ K+ permeability (Astrocyte characteristic)
Answer: Active neurons lose K+ into the extracellular spaces,
which would act as a positive feedback system for depolarization
if the K+ was not trapped by the astrocytes. They take up K+ by a
pump (Na+/K+ ATPase pump), and co-transporters (Na+/K+/Cl-
and K+/Cl- exchangers).
◉ Gap Junctions (Astrocyte characteristic)
,Answer: Astrocytes are coupled to each other, as well as other
glial cells and neurons through gap junctions. This may serve to
help modulate activity and sensitivity in the CNS.
◉ Neurotransmitters (Astrocyte characteristic)
Answer: Astrocytes synthesize over 20 different
neurotransmitters and take up excess neurotransmitters to help
terminate signals at the synapse.
◉ Growth factors (Astrocyte characteristic)
Answer: Astrocytes secrete a variety of growth factors, which are
important for the establishment of fully functioning excitatory
synapses.
◉ Blood Flow (Astrocyte characteristic)
Answer: Astrocytes can modulate blood flow in the brain by
inducing localized vasodilation or vasoconstriction. This
modulation can occur through gap junctions between the
astrocytes and the endothelial cells of brain blood vessels.
◉ Which of the following is a component of the central nervous
system?
Answer: Spinal cord.
◉ Which of the following nerve tissue cells controls most of what
enters and exits central nervous system neurons?
, A) Astrocytes
B) Oligodendrocytes
C) Schwann cells
D) Satellite cells
E) Microglial cells
Answer: Astrocytes
◉ Which of the following statements correctly describes
microglia?
A) Microglia help to circulate cerebrospinal fluid within the CNS.
B) Microglia are phagocytic cells residing within the CNS.
C) Microglia generate myelin sheaths in the PNS.
D) Microglia generate myelin sheaths in the CNS.
Answer: Microglia are phagocytic cells residing within the CNS.
◉ Which of the following cells makes CSF?
QUESTIONS AND SOLUTIONS
◉ glial cells
Answer: the supporting units
◉ central nervous system (CNS)
Answer: The CNS consists of neurons associated with central
processing and which are located in the brain and spinal cord. if
the entire structure of the neuron is contained within the brain
and/or spinal cord, the neuron would be considered part of the
CNS.
◉ peripheral nervous system (PNS)
Answer: The peripheral nervous system (PNS) consists of neurons
associated with sensory input (afferent) and motor output
(efferent), and functions to connect the central nervous system to
all other parts of the body. if any part of the neuronal structure is
located outside of the brain and/or spinal cord the neuron would
be considered part of the PNS
◉ Oligodendrocytes
Answer: a glial cell similar to an astrocyte but with fewer
protuberances, concerned with the production of myelin in the
central nervous system.
,◉ What four types of glial cells are in the CNS?
Answer: the astrocyte, the oligodendrocyte, the ependymal, and
the microglial cell.
◉ astrocyte
Answer: Astrocytes have an enormous amount of processes that
wrap around blood vessels and neurons. Because of this
arrangement, astrocytes are ideally positioned to control and
modify the extracellular environment around neurons. Most of the
functions of the astrocyte are attributed to controlling this
environment
◉ Glycogen storage (Astrocyte characteristic)
Answer: Astrocytes store all the glycogen present in the CNS. This
glycogen is used to help meet the high metabolic needs of the CNS.
The main source is blood glucose, but glycogen levels can sustain
the need for 5 to 10 min.
◉ K+ permeability (Astrocyte characteristic)
Answer: Active neurons lose K+ into the extracellular spaces,
which would act as a positive feedback system for depolarization
if the K+ was not trapped by the astrocytes. They take up K+ by a
pump (Na+/K+ ATPase pump), and co-transporters (Na+/K+/Cl-
and K+/Cl- exchangers).
◉ Gap Junctions (Astrocyte characteristic)
,Answer: Astrocytes are coupled to each other, as well as other
glial cells and neurons through gap junctions. This may serve to
help modulate activity and sensitivity in the CNS.
◉ Neurotransmitters (Astrocyte characteristic)
Answer: Astrocytes synthesize over 20 different
neurotransmitters and take up excess neurotransmitters to help
terminate signals at the synapse.
◉ Growth factors (Astrocyte characteristic)
Answer: Astrocytes secrete a variety of growth factors, which are
important for the establishment of fully functioning excitatory
synapses.
◉ Blood Flow (Astrocyte characteristic)
Answer: Astrocytes can modulate blood flow in the brain by
inducing localized vasodilation or vasoconstriction. This
modulation can occur through gap junctions between the
astrocytes and the endothelial cells of brain blood vessels.
◉ Which of the following is a component of the central nervous
system?
Answer: Spinal cord.
◉ Which of the following nerve tissue cells controls most of what
enters and exits central nervous system neurons?
, A) Astrocytes
B) Oligodendrocytes
C) Schwann cells
D) Satellite cells
E) Microglial cells
Answer: Astrocytes
◉ Which of the following statements correctly describes
microglia?
A) Microglia help to circulate cerebrospinal fluid within the CNS.
B) Microglia are phagocytic cells residing within the CNS.
C) Microglia generate myelin sheaths in the PNS.
D) Microglia generate myelin sheaths in the CNS.
Answer: Microglia are phagocytic cells residing within the CNS.
◉ Which of the following cells makes CSF?
