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SI Bio6 Dr. Wright’s class
made by Pyeongsug Kim
Revised: 03/14/10
Chap 7. Nervous system
* It is your responsibility to check the answers. If you find any wrong answer, email
me([email protected]) immediately!
1. Match the term.(The answer may be more than one)
Oligodendrocytes, astrocytes,
microglia, ependymal cells
Schwann cell
satellite cells
Supports neuron cells in CNS (glial cells in CNS)
Supports neuron cells in PNS.
ependymal cells
lines brain ventricles and the central canal of the spinal cord.
astrocytes
Help with ion uptake and with neurotransmitter uptake
oligodendrocytes
A single one of these can myelinate many axons on different on different neurons.
oligodendrocytes ,
Schwann cell
Produces myelin
oligodendrocytes
Produces myelin in CNS
Schwann cell
Produces myelin in PNS
act as glucose transport carriers, which help move glucose from blood to brain
astrocytes
(feeding neurons in the brain)
microglia
astrocytes
Acts as phagocyte
ependymal cells
Forms part of the chroid plexus, the structure that produces cerebrospinal fluid
astrocytes
Most common glial cell in CNS.
regulate neuronal activity by recycling or releasing transmitters.
astrocytes
a. Schwann cell
e. satellite cells
Forms the blood-brain barrier.
b. oligodendrocytes
f. ependymal cells
c. astrocytes
d. microglia
2. a. Compare myelinated axon from unmyelinated axon. (in other word, if the cell produce myelin sheath died what
would happen?)
Myelinated axon conducts signal(impulse) faster than unmyelinated axon.
b. What would happen to the nervous system (be specific) if the Schwann cells died (what part of the nervous
system would be affected and how)?
Axons in PNS conduct signal (impulse) slower.
c. What would happen to the nervous system (be specific) if the oligodendrocytes died (what part of the
nervous system would be affected and how)?
Axons in CNS conduct signal (impulse) slower.
d. Name two different types of glial cells and describe their specific roles in supporting the neurons including
whether the cells are supporting CNS or PNS.
oligodendrocytes
Produces myelin in CNS
astrocytes
regulate neuronal activity by recycling or releasing transmitters in CNS
Schwann cell
Produces myelin in PNS
Etc… see problem 1
SI Bio6 Dr. Wright’s class
3. Indicate: EPSPs, IPSPs, both or neither
made by Pyeongsug Kim
Revised: 03/14/10
Both
Occurs in a postsynaptic membrane
Neither
Occurs in a presynaptic membrane
EPSP
Occurs when nicotinic receptor bind 2 AChs and the channel is activated.
Occurs when Muscarinic receptor bind 1 AChs and the G protein is activated and
IPSP
adjacent channel is activated.
IPSP
Occurs when a G protein-activated potassium channel is activated.
IPSP
These would prevent excitation of the postsynaptic cell.
EPSP
Occurs when a sodium channel is opened in the postsynaptic cell.
EPSP
Cause excitation of the postsynaptic cell.
Neither
Occurs in the absence of neurotransmitters in skeletal muscles.
IPSP
Associated with hyperpolarization of the postsynaptic membrane.
EPSP
Associated with depolarization of the postsynaptic membrane.
EPSP
Associated with Na+ channel open in the postsynaptic membrane.
IPSP
IPSP
Associated with K+ channel open in the postsynaptic membrane.
Occur when axon of presynaptic neuron cause postsynaptic inhibition.
both
occur via diffusion when the ion channel is open.
EPSPs,
IPSPs,
both
or neither
4. Match the term.
ion channels
the structures which, when open, make a plasma membrane more permeable to ions.
depolarization
threshold
the “reversal” of membrane polarity caused when sodium ion enters the cell.
depolarization to this level (about –55 mV) initiates the movement of sodium.
repolarization
the process that results in the return to the membrane resting potenetial.
action potential
Wave is formed by rapid depolarization of the membrane by Na+
influx; followed by rapid repolarization by K+ efflux.
depolarization
occurs when membrane potential becomes more positive
action potential
Is triggered by depolarization to threshold.
action potential
a wave of MP change that sweeps along the axon from cell body to synapse
repolarization
Is caused by K+ diffusion out of axon
action potential
Occurs where there are regions lots of Na+-gated channels
depolarization
Is caused by Na+ diffusion into axon
myelin
the substance that facilitates conduction of a nerve impulse along an axon
action potential
Is often called “All or None” and its amplitudes are the same.
Blood-brain barrier
a. depolarization
f. action potential
Is fomed due to effects of astrocytes on brain capillaries.
b. ion channels
c. threshold
e. repolarization
f. myelin
g. Blood-brain barrier
5. Briefly answer the following questions about the actionpotential
a. In the depolarization, what ion enters the cell? Na+
b. In the hyperpolarization, what ion leaves the cell? K+
g. neurotransmitters
SI Bio6 Dr. Wright’s class
made by Pyeongsug Kim
Revised: 03/14/10
c. What ion enters the cell at the axon terminals and initiates the process of neurotransmitter release? Ca+
d. When acetylcholines(neurotransmitters) bind to muscarinic, Which ion channels will be open? Cause
depolarization, repolarization, or hyperpolarization? The ion in or out of the cell? K+; hyperpolarizaion; out
e. Is an EPSP produced by depolarization or hyperpolarization of the synaptic cell (indicate which)? Depolarization
f. What is the substance that speeds up conduction of a nervous impulses when it is wrapped around an axon?
Myelin
g. Name two glial cells that produce this substance indicating CNS or PNS in each. Shawnn(PNS),
Oligodendrocytes(CNS)
5. Choose the answer. The answer may be more than one.
Acetylcholine
This is the major neurotransmitter involved in skeletal muscle stimulation.
serotonin
Drugs like prozac inhibit the reuptake of this
Nicotinic and muscarinic receptors bind this.
Acetylcholine
These neurotransmitters are released by preganglionic neurons in the
Acetylcholine
ANS(autonomic nervous) system
Acetylcholine,,norepinephrine
These neurotransmitters are released by postganglionic neurons in the
ANS(autonomic nervous) system
Acetylcholine
These neurotransmitters are released by somatic motor neurons.
Dopamine
Parkinson’s disease results from loss of this activity in the nigrostriatal system
Dopamine
norepinephrine
Schizophrenia results from overactivity of this in the mesolimbic system.
These neurotransmitters may cause increase heart rate.
Acetylcholine, norepinephrine
These neurotransmitters may be released in both CNS and PNS
serotonin
Involved in regulation of mood, behavior, appetite and cerebral circulation.
serotonin
a. Dopamine,
If these neurotransmitters are not enough, depression may occur in the person.
b. Acetylcholine, c. serotonin
d. norepinephrine