Download Chapter 48 , 10th edition 1) What happens when a resting neuron`s

 Chapter 48 , 10th edition
1) What happens when a resting neuron's membrane depolarizes?
A)The neuron's membrane voltage becomes more positive.
B)The cell's inside is more negative than the outside.
C)There is a net diffusion of Na+ out of the cell.
D)The equilibrium potential for K+ (EK) becomes more positive.
Answer: a
2) A common feature of action potentials is that they
A)can undergo temporal and spatial summation.
B)move at the same speed along all axons.
C)are triggered by a depolarization that reaches the threshold.
D) the membrane to hyperpolarize and then depolarize.
Answer: c
3) Where are neurotransmitter receptors located?
A)the nodes of Ranvier
B)the nuclear membrane
C)synaptic vesicle membranes
D)the postsynaptic membrane
Answer:d
4) Why are action potentials usually conducted in one direction?
A)Voltage-gated channels for both Na+ and K+ open in only one direction.
B)The axon hillock has a higher membrane potential than the terminals of the axon.
C)Ions can flow along the axon in only one direction.
D)The brief refractory period prevents reopening of voltage-gated Na+ channels.
Answer:d
5) Which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?
A)Ligand-gated channels open, allowing neurotransmitters to enter the synaptic cleft.
B)Synaptic vesicles fuse with the membrane.
C)An EPSP or IPSP is generated in the postsynaptic cell.
D)Voltage-gated calcium channels in the membrane open.
Answer:d
6) Suppose a particular neurotransmitter causes an IPSP in postsynaptic cell X and an EPSP in postsynaptic cell
Y. A likely explanation is that
A)the threshold value in the postsynaptic membrane is different for cell X and cell Y.
B)the axon of cell X is myelinated, but that of cell Y is not.
C)cells X and Y express different receptor molecules for this particular neurotransmitter.
D)only cell Y produces an enzyme that terminates the activity of the neurotransmitter.
Answer:C
7) Neurons communicate by __________.
A)short-distance electrical signals
B)long-distance chemical signals
C)short-distance electrical signals and long-distance chemical signals
D)short-distance chemical signals and long-distance electrical signals
E)none of the listed responses
Answer:d
8) What are ganglia
A)neurons
B)brains
C)electrical signals
D)clusters of nerve cell bodies
E)None of the listed responses is correct.
Answer:d
9) A neuron that transmits an impulse to the central nervous system after the neuron is stimulated by the
environment is called a__________.
A)sensory neuron
B)motor neuron
C)interneuron
D)autonomic neuron
E)effector
Answer:a
10) Which of the following is specifically a part or a function of the central nervous system?
A)sensory receptors
B)sensory input
C)integration
D)motor output
E)dendrites
Answer:c
11) The part of a neuron that carries nerve impulses toward the cell body is called a __________.
A)nerve
B)synapse
C)neurotransmitter
D)dendrite
E)axon
Answer:d
12) Cells that provide metabolic and structural support to the neurons are called __________.
A)sensory and motor neurons
B)neurotransmitters
C)interneurons
D)dendrites
E)glia
Answer:e
13) If your fingers touch a hot stove and you suddenly pull back, you have experienced a reflex. What is the
correct order of the information processing in this reflex?
A)sensory input, integration, motor output
B)motor output, sensory input, integration
C)motor output, integration, sensory input
D)integration, motor output, sensory input
E)integration, sensory input, motor output
Answer:a
14) Which of the following statements is correct?
A)A neuron only has a single axon.
B)Dendrites branch off axons.
C)Axons receive signals from other neurons.
D)The peripheral nervous system is most closely associated with interneurons.
E)None of the listed responses is correct.
Answer:a
15) In descriptions of synapse organization, which type of cell is the transmitting neuron and which type of
neuron, muscle, or gland cell receives the signal?
A)presynaptic ... postsynaptic
B)postsynaptic ... presynaptic
C)active ... passive
D)producer ... consumer
E)None of the listed responses is correct.
Answer:a
16) Which of the following statements is correct?
A)The nucleus of a neuron is located in the axon hillock.
B)Synaptic cells nourish neurons, insulate the axons of neurons, and/or regulate the extracellular fluid
surrounding the neurons.
C)The vast majority of neurons in the brain are sensory neurons.
D)Sensory neurons transmit signals to muscle cells.
D)None of the listed responses is correct.
Answer:e
17) Which of the following statements about the resting potential is true?
A)The neuron's plasma membrane is much more permeable to sodium than to potassium.
B)The concentration of sodium is much higher inside the cell than outside.
C)The chloride-hydrogen pump plays a role in maintaining the resting potential.
D)Inside the cell, the concentration of potassium is much higher than the concentration of sodium.
E)All of the listed responses are correct.
Answer:d
18) The sodium-potassium pump __________.
A)expels sodium from the cell
B)expels sodium and potassium from the cell
C)pumps sodium into the cell
D)pumps sodium and potassium into the cell
E)allows ions to move in either direction through the membrane
Answer:a
19) Which of the following statements is true?
A)Ion channels allow ions to cross the cell membrane against their concentration gradients.
B)Ion channels are selectively permeable, permitting only certain ions to pass.
C)All cells have an equilibrium potential, which is a difference in electrical charges across their plasma
membrane.
D)Concentration gradients of proteins across the plasma membrane represent potential energy.
E)None of the listed responses is correct.
Answer:b
20) Blocking potassium ion channels in a mammalian cell membrane would __________.
A)increase the resting potential
B)decrease the magnitude of the membrane potential
C)increase potassium's equilibrium potential
D)decrease sodium's equilibrium potential
E)increase the magnitude of the membrane potential
Answer:b
21) What is an increase in the magnitude of the membrane potential called?
A)hyperpolarization
B)hypopolarization
C)depolarization
D)a refractory period
E)None of the listed responses is correct.
Answer:a
22) A drug that causes potassium to leak out of a neuron, increasing the positive charge on the outside, would
__________.
A)make it easier to trigger action potentials in the neuron
B)cause the cell to release its neurotransmitter
C)speed up nerve signals traveling the length of the cell
D)act as a stimulant
E)inhibit transmission of nerve signals by the neuron
Answer:e
23) Threshold is of great significance in the physiology of neurons. What happens if threshold is NOT reached?
A)the neuron cannot regain its resting potential
B)the action potential will be "inversed," with a flux of sodium out of the cell rather than into it
C)positive-feedback depolarization will not occur
D)an action potential will be reached
E)None of the listed responses is correct.
Answer:c
24) Schwann cells make up the __________.
A)neurons
B)nodes of Ranvier
C)myelin sheath in axons of the PNS (peripheral nervous system)
D)axons
E)myelin sheath in axons of the CNS (central nervous system)
Answer:c
25) An action potential is __________.
A)a traveling wave of depolarization in the neuron membrane
B)a brief neutralization of the charges on sodium and potassium ions
C)a sudden increase in speed by the sodium-potassium pump
D)a sudden reversal of the sodium-potassium pump
E)described by none of the listed responses
Answer:a
26) The period in which an axon membrane CANNOT generate an action potential is called __________.
A)the refractory period
B)saltatory conduction
C)depolarization
D)a resting potential
E)an action potential
Answer:a
27) Saltatory conduction means that the membrane potential changes __________.
A)only where there is diffusion of sodium and potassium ions
B)only at the nodes of Ranvier
C)along the entire length of the axon
D)in an all-or-none fashion
E)from polarized to depolarized and back to polarized
Answer:b
28) Action potentials are generated along a neuron because __________.
A)of cytoplasmic streaming within the neuron
B)depolarization of the membrane at one point causes an increase of permeability to sodium at the next point
C)they are pulled along by positive-negative attraction
D)the neuron cytoskeleton conducts electricity as long as an ion gradient is maintained by the sodiumpotassium pump
E)of all of the listed responses
Answer:b
29) How are neurons structurally adapted to chemically transmit impulses to neighboring neurons?
A)*Axon terminals contain neurotransmitter within synaptic vesicles.
B)They have numerous nodes of Ranvier.
C)They have numerous dendrites.
D)They have Schwann cells that surround axons.
E)None of the listed responses is correct.
Answer:a
30) Which of the following statements about the transmission across a typical chemical synapse is true?
A)Neurotransmitter molecules are stored in vesicles in the dendrites.
B)Action potentials trigger chemical changes that make the neurotransmitter vesicles fuse with the plasma
membrane of the receiving cell.
C)Vesicles containing neurotransmitter molecules diffuse to the receiving cell's plasma membrane.
D)Neurotransmitter molecules bind to receptors in the sending cell's plasma membrane.
E)The binding of neurotransmitter molecules to receptors on the postsynaptic cell membrane results in changes
to the behavior of the postsynaptic cell.
Answer:e
31) Acetylcholinesterase is the enzyme that degrades acetylcholine. What effect on nerve transmission would
occur following the administration of a chemical that inhibited acetylcholinesterase?
A)There would be no effect.
B)Synaptic transmission would be prevented; muscle paralysis would occur.
C)It would be identical to giving an anesthetic, but it would last permanently.
D)Continuous excitatory postsynaptic potentials would occur in the postsynaptic neuron.
E)The presynaptic neuron would be inactivated.
Answer:d
32) In humans, making more serotonin available to brain cells typically __________.
A)increases the stimulatory effects of caffeine
B)produces an effect on mood
C)counteracts the effects of alcohol
D)causes the heart to beat faster
E)depresses the central nervous system
Answer:b
33) Which of the following is a natural pain reliever?
A)epinephrine
B)acetylcholine
C)endorphins
D)dopamine
E)substance P
Answer:c
34) Which of the following correctly pairs up a type of synapse and its characteristic?
A)electrical synapse ... gap junctions
B)electrical synapse ... neurotransmitters
C)junctional synapses ... ligand-gated ion channels
D)chemical synapses ... gap junctions
E)None of the listed responses is correct.
Answer:a
35) Which of the following neurotransmitters typically has inhibitory effects?
A)GABA (gamma-aminobutyric acid)
B)glutamate
C)norepinephrine
D)substance P
E)None of the listed responses is correct.
Answer:a
36) Which of the following is a mechanism by which neurotransmitters can be rapidly cleared from the synaptic
cleft
A)The neurotransmitters are actively transported back into the presynaptic cells to be repackaged into synaptic
vesicles.
B)The neurotransmitters are transferred to glia to be metabolized.
C)Neurotransmitters are removed by simple diffusion.
D)Neurotransmitters are removed by enzymatic hydrolysis of the neurotransmitter.
E)All of the listed responses are correct.
Answer:e
37) The interplay of multiple excitatory and inhibitory inputs most affects what part of a neuron?
A)axon hillock
B)dendrites
C)the nucleus
D)the neuron's cytoskeleton
E)the axon
Answer:a