Question 1

Action potentials

Accepted Answer

A)  are initiated by the membrane's increased permeability to potassium. 
B)  return to resting when the sodium channels open. 
C)  can be triggered in very rapid succession, with no delay. 
D)  involve voltage-gated channels in the membrane. 
E)  are propagated only because chloride ions move through the membrane. 
A)  are initiated by the membrane's increased permeability to potassium. 
B)  return to resting when the sodium channels open. 
C)  can be triggered in very rapid succession, with no delay. 
D)  involve voltage-gated channels in the membrane. 
E)  are propagated only because chloride ions move through the membrane.

Question 2

Electrical synapses are different from chemical synapses because they

Accepted Answer

A)  transmit in only one direction. 
B)  contain only one gap junction. 
C)  have connexons that link the two neurons by forming pores. 
D)  integrate information well. 
E)  can be either excitatory or inhibitory. 
A)  transmit in only one direction. 
B)  contain only one gap junction. 
C)  have connexons that link the two neurons by forming pores. 
D)  integrate information well. 
E)  can be either excitatory or inhibitory.

Question 3

_______ allow(s) the study of single ion channels.

Accepted Answer

A)  Patch clamping 
B)  Micro sensors 
C)  Micro clamping 
D)  The electron microscope 
E)  Electron sensors 
A)  Patch clamping 
B)  Micro sensors 
C)  Micro clamping 
D)  The electron microscope 
E)  Electron sensors

Question 4

Which of the following statements about voltage-gated channel proteins is true?

Accepted Answer

A)  If the membrane voltage reaches threshold potential, ions are pumped through the membrane. 
B)  If the membrane voltage reaches threshold potential, ions can diffuse through the membrane. 
C)  Ions can move through the membrane only if the overall membrane voltage stays the same. 
D)  Ions are pumped through the membrane in order to maintain existing membrane voltage. 
E)  When the gates close, membrane voltage does not change. 
A)  If the membrane voltage reaches threshold potential, ions are pumped through the membrane. 
B)  If the membrane voltage reaches threshold potential, ions can diffuse through the membrane. 
C)  Ions can move through the membrane only if the overall membrane voltage stays the same. 
D)  Ions are pumped through the membrane in order to maintain existing membrane voltage. 
E)  When the gates close, membrane voltage does not change.

Question 5

Some medications that elevate mood and relieve anxiety

Accepted Answer

A)  enhance the activity of serotonin at the synapse. 
B)  slow the reuptake of serotonin. 
C)  increase endorphins. 
D)  Both a and b 
E)  All of the above 
A)  enhance the activity of serotonin at the synapse. 
B)  slow the reuptake of serotonin. 
C)  increase endorphins. 
D)  Both a and b 
E)  All of the above

Question 6

The binding of an inhibitory neurotransmitter to the postsynaptic receptors results in

Accepted Answer

A)  depolarization of the membrane. 
B)  generation of an action potential. 
C)  hyperpolarization of the membrane. 
D)  increased permeability of the membrane to sodium ions. 
E)  increased permeability of the membrane to calcium ions. 
A)  depolarization of the membrane. 
B)  generation of an action potential. 
C)  hyperpolarization of the membrane. 
D)  increased permeability of the membrane to sodium ions. 
E)  increased permeability of the membrane to calcium ions.

Question 7

Muscarinic receptors of acetylcholine

Accepted Answer

A)  are found in heart muscle. 
B)  tend to be inhibitory. 
C)  are an example of a metabotropic receptor. 
D)  Both a and b 
E)  All of the above 
A)  are found in heart muscle. 
B)  tend to be inhibitory. 
C)  are an example of a metabotropic receptor. 
D)  Both a and b 
E)  All of the above

Question 8

The difference between slow and fast synapses is

Accepted Answer

A)  the width of the synaptic cleft. 
B)  the size of the synapse. 
C)  whether or not the neurotransmitter acts directly on ion channels. 
D)  the density of receptors on the postsynaptic membrane. 
E)  the amount of neurotransmitter that is released. 
A)  the width of the synaptic cleft. 
B)  the size of the synapse. 
C)  whether or not the neurotransmitter acts directly on ion channels. 
D)  the density of receptors on the postsynaptic membrane. 
E)  the amount of neurotransmitter that is released.

Question 9

When you touch a hot stove a nerve impulse travels up your arm, passes briefly through your central nervous system, and a response is sent down your arm to move your hand. The system described here

Accepted Answer

A)  would also rely on an effector. 
B)  has evolved only in humans. 
C)  constitutes a neural network. 
D)  does not involve the peripheral nervous system. 
E)  Both a and c 
A)  would also rely on an effector. 
B)  has evolved only in humans. 
C)  constitutes a neural network. 
D)  does not involve the peripheral nervous system. 
E)  Both a and c

Question 10

Which of the following statements about dopamine is true?

Accepted Answer

A)  It is a derivative of tyrosine. 
B)  It is a neurotransmitter of the central nervous system. 
C)  It is a monoamine. 
D)  All of the above 
E)  None of the above 
A)  It is a derivative of tyrosine. 
B)  It is a neurotransmitter of the central nervous system. 
C)  It is a monoamine. 
D)  All of the above 
E)  None of the above

Question 11

Which of the following differs the least among species?

Accepted Answer

A)  Brainstem 
B)  Olfactory lobe 
C)  Cerebrum 
D)  Cerebellum 
E)  These all vary equally among species. 
A)  Brainstem 
B)  Olfactory lobe 
C)  Cerebrum 
D)  Cerebellum 
E)  These all vary equally among species.

Question 12

Graded membrane potentials

Accepted Answer

A)  can be more negative than resting potential. 
B)  can be less negative than resting potentials. 
C)  integrate the many synaptic inputs to a cell. 
D)  are important means of summing sensory inputs. 
E)  are all of the above. 
A)  can be more negative than resting potential. 
B)  can be less negative than resting potentials. 
C)  integrate the many synaptic inputs to a cell. 
D)  are important means of summing sensory inputs. 
E)  are all of the above.

Question 13

The active ingredients in many nerve gases belong to a class of chemicals called anticholinesterases (chemicals that block acetylcholinesterase). Suggest a possible synaptic mechanism to explain how these chemicals can damage an animal's nervous system.

Accepted Answer

Acetylcholine is the neurotransmitter us

Question 14

Mice with modified NMDA receptors

Accepted Answer

A)  run through mazes more slowly than normal mice do. 
B)  remember the routes in mazes for longer periods of time than normal mice do. 
C)  fail to learn tasks. 
D)  remember the routes in mazes for shorter periods of time than normal mice do. 
E)  a, c, and d 
A)  run through mazes more slowly than normal mice do. 
B)  remember the routes in mazes for longer periods of time than normal mice do. 
C)  fail to learn tasks. 
D)  remember the routes in mazes for shorter periods of time than normal mice do. 
E)  a, c, and d

Question 15

Which of the following statements about acetylcholine is false?

Accepted Answer

A)  Acetylcholine is a neurotransmitter. 
B)  Acetylcholine is found at mammalian neuromuscular junctions. 
C)  Both smooth muscles and skeletal muscles respond to acetylcholine. 
D)  Acetylcholine is degraded by acetylcholinesterase. 
E)  Acetylcholine increases contractility of the heart. 
A)  Acetylcholine is a neurotransmitter. 
B)  Acetylcholine is found at mammalian neuromuscular junctions. 
C)  Both smooth muscles and skeletal muscles respond to acetylcholine. 
D)  Acetylcholine is degraded by acetylcholinesterase. 
E)  Acetylcholine increases contractility of the heart.

Question 16

When the neurotransmitter diffuses across the synaptic cleft,

Accepted Answer

A)  it automatically causes depolarization of the post­synaptic membrane. 
B)  it can be excitatory or inhibitory, depending on the type of postsynaptic membrane. 
C)  a single molecule is sufficient to trigger activation of the postsynaptic membrane. 
D)  only a few molecules make it to the postsynaptic membrane. 
E)  it must move through nodes in the myelin sheath. 
A)  it automatically causes depolarization of the post­synaptic membrane. 
B)  it can be excitatory or inhibitory, depending on the type of postsynaptic membrane. 
C)  a single molecule is sufficient to trigger activation of the postsynaptic membrane. 
D)  only a few molecules make it to the postsynaptic membrane. 
E)  it must move through nodes in the myelin sheath.

Question 17

The rising phase of an action potential is due to the

Accepted Answer

A)  closing of K+ channels. 
B)  opening of chemically gated Na+ channels. 
C)  closing of voltage-gated Ca2+ channels. 
D)  opening of voltage-gated Na+ channels. 
E)  spread of positive current along the plasma membrane. 
A)  closing of K+ channels. 
B)  opening of chemically gated Na+ channels. 
C)  closing of voltage-gated Ca2+ channels. 
D)  opening of voltage-gated Na+ channels. 
E)  spread of positive current along the plasma membrane.

Question 18

Metabotropic receptors

Accepted Answer

A)  are ion channels. 
B)  are a type of ionotropic receptor. 
C)  are only found in mammals. 
D)  are G protein-linked receptors. 
E)  enable fast and short-lived postsynaptic cell responses. 
A)  are ion channels. 
B)  are a type of ionotropic receptor. 
C)  are only found in mammals. 
D)  are G protein-linked receptors. 
E)  enable fast and short-lived postsynaptic cell responses.

Question 19

The gas _______ is used as an intercellular messenger by neurons.

Accepted Answer

The answer of The gas _______ is used as an...

Question 20

Explain how an action potential travels more quickly down an axon wrapped in myelin than it does down an unmyelinated axon.

Accepted Answer

The conduction of an action potential do

Exam 45: Neurons and Nervous Systems

Action potentials

Electrical synapses are different from chemical synapses because they

_______ allow(s) the study of single ion channels.

Which of the following statements about voltage-gated channel proteins is true?

Some medications that elevate mood and relieve anxiety

The binding of an inhibitory neurotransmitter to the postsynaptic receptors results in

Muscarinic receptors of acetylcholine

The difference between slow and fast synapses is

When you touch a hot stove a nerve impulse travels up your arm, passes briefly through your central nervous system, and a response is sent down your arm to move your hand. The system described here

Which of the following statements about dopamine is true?

Which of the following differs the least among species?

Graded membrane potentials

The active ingredients in many nerve gases belong to a class of chemicals called anticholinesterases (chemicals that block acetylcholinesterase). Suggest a possible synaptic mechanism to explain how these chemicals can damage an animal's nervous system.

Mice with modified NMDA receptors

Which of the following statements about acetylcholine is false?

When the neurotransmitter diffuses across the synaptic cleft,

The rising phase of an action potential is due to the

Metabotropic receptors

The gas _______ is used as an intercellular messenger by neurons.

Explain how an action potential travels more quickly down an axon wrapped in myelin than it does down an unmyelinated axon.

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