Deck 6: Neuronal Signaling and the Structure of the Nervous System

Question 1

The Na,K-ATPase in a nerve cell

A)Maintains an electrical gradient such that the inside is negative with respect to the outside
B)Maintains a concentration gradient for K⁺ such that diffusion forces favor movement of K⁺ into the cell
C)Maintains an electrical gradient at the equilibrium potential of K⁺
D)Transports an equal number of sodium and potassium ions
E)Both maintains an electrical gradient such that the inside is negative with respect to the outside and transports an equal number of sodium and potassium ions are correct

Answer 1

A

Question 2

Ohm's law (I = E/R)states that current increases with

A)Increasing voltage or increasing resistance
B)Decreasing voltage or decreasing resistance
C)Increasing voltage or decreasing resistance
D)Decreasing voltage or increasing resistance
E)None of the choices are true

Answer 2

C

Question 3

The difference in electrical charge between two points

A)Is called the potential difference between those points
B)Is called the diffusion potential between those points
C)Depends upon charge flow between those points
D)Is the same for all ions

Answer 3

A

Question 4

The equilibrium potential of a given ion across a membrane is

A)A function of the concentration of that ion on both sides of the membrane
B)The potential at which there is no net movement of that ion across the membrane
C)The potential difference across the membrane that creates an electric force favoring diffusion of the ion in one direction that is equal in magnitude and opposite in direction to the diffusion force provided by the concentration difference of the ion across the membrane
D)Both a function of the concentration of that ion on both sides of the membrane and the potential at which there is no net movement of that ion across the membrane are correct
E)All of the choices are correct

Question 5

The equilibrium potential of K ions in nerve cells is about -90 mV.The membrane potential of typical nerve cells at rest is -70 mV.Therefore

A)Increasing the permeability of a resting neuronal membrane to K ions will increase the membrane potential (that is, make it more negative, inside with respect to outside)
B)In nerve cells at rest, there is a net diffusion of K ions out of the cell
C)Increasing the membrane potential of a nerve cell would slow the diffusion of K ions out of it
D)Potassium is not the only permeant ion at rest
E)All of the choices are true

Question 6

An increase in the extracellular concentration of K⁺ above normal would result in

A)Depolarization of resting nerve cells
B)Hyperpolarization of resting nerve cells
C)No change in the resting membrane potential

Question 7

If the concentration of ATP were depleted in a typical nerve cell,the

A)Resting membrane potential would increase (become more negative)
B)Resting membrane potential would decrease (become less negative)
C)Concentration gradient for Na⁺ would remain the same
D)Resting membrane potential would eventually become positive inside with respect to outside
E)None of the choices are correct

Question 8

Which of the following is/are functions of the human nervous system?

A)Receiving, storing and processing information on the internal and external environments
B)Bringing about changes in physiology and/or behavior to ensure optimal functions of homeostatic mechanisms
C)Secretion of hormones
D)Coordination of movement
E)All of the choices are correct

Question 9

The membrane potential of most neurons at rest is

A)Equal to the equilibrium potential of potassium ion
B)Equal to the equilibrium potential of sodium ion
C)Slightly more negative than the equilibrium potential of potassium ion
D)Slightly more positive than the equilibrium potential of potassium ion
E)Both equal to the equilibrium potential of sodium ion and slightly more negative than the equilibrium potential of potassium ion

Question 10

An increase in the extracellular concentration of K⁺ above normal would result in

A)A decrease in intracellular K⁺
B)An increase in intracellular K⁺
C)A decrease in intracellular Na⁺
D)An increase in intracellular Na⁺
E)No change in intracellular ion concentrations

Question 11

Which of the following statements concerning the permeability of a typical nerve cell membrane at rest is true?

A)The permeability to Na ion is very much greater than the permeability to K ion
B)All of the K ion channels in the membrane are open
C)The voltage-gated Na ion channels are inactivated
D)The voltage-gated Na ion channels are closed
E)None of the choices are true

Question 12

Which of the following is not true about axon transport?

A)It refers to the passage of materials from the cell body of a neuron to the axon terminals
B)It refers to the passage of materials from axon terminals to the cell body of a neuron
C)It refers to the transport of materials across the axonal membrane
D)It is especially important for maintaining the integrity of neurons with long axons

Question 13

Compartments A and B are separated by a membrane that is permeable to K+ but not to Cl-.At time zero,a solution of KCl is poured into compartment A and pure H2O is poured into compartment B.At equilibrium,

A)The concentration of K+ in A will be lower than it was at time zero
B)Diffusion of K+ from A to B will be equal to the diffusion of K+ from B to A
C)There will be a potential difference across the membrane,with side A negative relative to side B
D)The electrical and diffusion potentials for K+ will be equal in magnitude and opposite in direction
E)All of the choices are correct

Question 14

Compartments A and B are separated by a membrane that is permeable to K+ but not to Cl-.At time zero,a solution of KCl is poured into compartment A and pure H2O is poured into compartment B.Now they are emptied and the membrane replaced with one that is permeable to both K+ and Cl-,but no other ions.At time zero,a solution of NaCl is poured into compartment A and a solution of KA (A is an anion other than Cl-)is poured into compartment B.At equilibrium,

A)Compartment A will be negatively charged relative to B
B)There is a net flux of K+ from B to A
C)There is a concentration gradient favoring Cl- diffusion from A to B and this gradient is balanced by an electric force favoring diffusion from B to A
D)Both there is a net flux of K+ from B to A and there is a concentration gradient favoring Cl- diffusion from A to B and this gradient is balanced by an electric force favoring diffusion from B to A are correct
E)All of the choices are correct

Question 15

Which is not true of myelin?

A)Is a fatty membranous sheath
B)Is formed by glial cells
C)Influences the rate of conduction of the electrical signal down an axon
D)Myelin covers all parts of the neuron: axon, cell body and dendrites
E)None of the choices are true

Question 16

Which of the following is not true of glial cells?

A)They form the myelin for axons
B)Neurons outnumber glial cells 10 to 1 in the nervous system
C)They deliver fuel molecules to neurons and remove the waste products of metabolism
D)They are important for the growth and development of the nervous system
E)They regulate the composition of the extracellular fluid in the CNS

Question 17

The resting membrane potential

A)Requires very few ions to be distributed unevenly
B)Is the same in all cells
C)Is oriented so that the cell's interior is positive with respect to the extracellular fluid
D)Occurs only in nerve and muscle cells
E)None of the choices are correct

Question 18

In a resting neuron,

A)The plasma membrane is freely permeable to sodium ion
B)The concentration of sodium ion is greater inside the cell than outside
C)The permeability of the plasma membrane to potassium ion is about 50 times greater than its permeability to sodium ion
D)The plasma membrane is completely impermeable to sodium ion
E)None of the choices are true

Question 19

The diffusion potential for Na⁺ across a nerve cell membrane

A)Favors its movement into the cell at resting potential
B)Favors its movement out of the cell at resting potential
C)Is equal and opposite to the electrical potential acting on sodium at resting potential
D)Is in the same direction as the diffusion potential for potassium
E)Both favors its movement into the cell at resting potential and is equal and opposite to the electrical potential acting on sodium at resting potential are correct

Question 20

A given neuron can

A)Be either a presynaptic neuron or a postsynaptic neuron
B)Receive information from more than one other neuron
C)Transmit information to more than one other neuron
D)Simultaneously release more than one type of neurotransmitter
E)Do all of these things

Question 21

A threshold stimulus applied to an excitable membrane is one that is just sufficient to

A)Trigger a graded potential in the membrane
B)Cause a change in membrane potential
C)Cause net inward movement of positive charge through the membrane
D)Be conducted to the axon hillock
E)Depolarize a dendrite

Question 22

For an action potential to occur,

A)The stimulus must reach or exceed threshold
B)Na⁺ influx must exceed K⁺ efflux
C)The membrane must be out of the relative refractory period
D)Both the stimulus must reach or exceed threshold and Na⁺ influx must exceed K⁺ efflux must happen
E)All of the choices must happen

Question 23

The relative refractory period of an axon coincides with the period of

A)Activation and inactivation of voltage-dependent Na⁺ channels
B)Increased Na⁺ flux into the cell
C)Increased K⁺ flux into the cell
D)Increased K⁺ flux out of the cell
E)Increased Na⁺ flux out of the cell

Question 24

During the rising (depolarizing)phase of an action potential,

A)PK⁺ becomes much greater than PNa⁺
B)PNa⁺ becomes much greater than PK⁺
C)PK⁺ is the same as PNa⁺
D)Na⁺ efflux (flow out of the cell) occurs
E)None of the choices occur

Question 25

Axons typically have abundant

A)Voltage-regulated channels for Na⁺ that open in response to depolarization
B)Voltage-regulated channels for K⁺ that open in response to hyperpolarization
C)Receptor-mediated channels for Na⁺
D)Both voltage-regulated channels for Na⁺ that open in response to depolarization and voltage-regulated channels for K⁺ that open in response to hyperpolarization are correct
E)All of the choices are correct

Question 26

At the peak of the action potential,

A)The electrical gradient for K⁺ tends to move this ion out of the cell
B)The concentration gradient for K⁺ tends to move this ion out of the cell
C)The permeability for K⁺ greatly increases
D)Both the electrical gradient for K⁺ tends to move this ion out of the cell and the concentration gradient for K⁺ tends to move this ion out of the cell occur
E)The electrical gradient for K⁺ tends to move this ion out of the cell, the concentration gradient for K⁺ tends to move this ion out of the cell and the permeability for K⁺ greatly increases occur

Question 27

An action potential does not restimulate the adjacent membrane that was previously depolarized because

A)Stimulation is inhibited by the myelin sheath
B)It is impossible for an action potential to be propagated along an axon toward the nerve cell body
C)The resting membrane potential of the axon is too high
D)The resting membrane potential of the axon is too low
E)This area of membrane is absolutely refractory to depolarization

Question 28

Which of the following statements regarding action potentials generated in a membrane is not true?

A)Action potentials travel decrementally down the membrane
B)An action potential generates a new action potential in an adjacent area of membrane
C)An action potential generates a local current that depolarizes adjacent membrane to threshold potential
D)The first action potential generated is the same size as the action potential ultimately generated at the end of the membrane
E)An action potential generated by a threshold stimulus is the same size as one generated by a supra-threshold stimulus

Question 29

Graded potentials

A)Include receptor potentials and postsynaptic potentials
B)Are conducted decrementally
C)Include depolarizing and hyperpolarizing potentials
D)Can be summed
E)Are described by all of the choices

Question 30

Which of the following statements concerning the properties of action potentials is true?

A)The rate of propagation of an action potential down an axon is independent of stimulus strength
B)Action potentials can be summed
C)A supra-threshold stimulus is required to stimulate an action potential during the absolute refractory period
D)Action potentials are conducted decrementally down the axon
E)None of the choices are true

Question 31

Action potentials are said to be "all-or-none" in character because

A)The rate of propagation of an action potential down an axon is independent of stimulus strength
B)They are associated with an absolute refractory period
C)A supra-threshold stimulus is required to stimulate an action potential during the relative refractory period
D)The amplitude of an action potential generated in any given neuron is the same, regardless of the stimulus strength
E)All of these statements describe the "all-or-none" character of action potentials

Question 32

Which of the following statements about the refractory period of a membrane is true?

A)The absolute refractory period refers to the period of time during which another action potential cannot be initiated in that part of the membrane that has just undergone an action potential, no matter how great the strength of the stimulus
B)The relative refractory period refers to the period of time during which another action potential can be initiated in that part of the membrane that has just undergone an action potential, if the stimulus is strong enough
C)The refractory period prevents the action potential from spreading back over the part of the membrane that just underwent an action potential
D)The refractory period places an upper limit on the frequency with which a nerve cell can conduct action potentials
E)All of the choices are correct

Question 33

The neural code that signals stimulus strength is

A)The size of action potentials
B)The frequency of action potentials
C)The duration of action potentials
D)Both the size of action potentials and the frequency of action potentials
E)All of the choices are correct

Question 34

Which of the following statements regarding the phases of an action potential is correct?

A)During the depolarizing phase, the permeability of the membrane to Na⁺ is greater than its permeability at rest
B)During the repolarizing phase, the permeability of the membrane to K⁺ is greater than its permeability at rest
C)The relative refractory period of the membrane coincides with the hyperpolarized and second repolarizing phases
D)Both during the depolarizing phase, the permeability of the membrane to Na⁺ is greater than its permeability at rest and during the repolarizing phase, the permeability of the membrane to K⁺ is greater than its permeability at rest are correct
E)All of the choices are correct

Question 35

During the rising phase of an action potential,voltage-gated

A)Na⁺ channels open
B)K⁺ channels open
C)Na⁺ channels close
D)K⁺ channels close
E)Both Na⁺ channels open and K⁺ channels close are correct

Question 36

Which of the following statements about the phases of an action potential are correct?

A)During the hyperpolarizing phase, the permeability of the membrane to sodium ion is greater than its permeability at rest
B)During the hyperpolarizing phase, the permeability of the membrane to potassium ion is greater than its permeability at rest
C)During the repolarizing phases, the permeability of the membrane to potassium ion is greater than its permeability at rest
D)Both during the hyperpolarizing phase, the permeability of the membrane to sodium ion is greater than its permeability at rest and during the repolarizing phases, the permeability of the membrane to potassium ion is greater than its permeability at rest are correct
E)Both during the hyperpolarizing phase, the permeability of the membrane to potassium ion is greater than its permeability at rest and during the repolarizing phases, the permeability of the membrane to potassium ion is greater than its permeability at rest are correct

Question 37

When an axon is stimulated to threshold,the voltage-gated

A)K⁺ channels open before the voltage-gated Na⁺ channels
B)Na⁺ channels are activated and then inactivated
C)K⁺ channels open at the same time as the voltage-gated Na⁺ channels
D)K⁺ channels are opened when Na⁺ binds to the channel
E)All of the choices are correct

Question 38

Which of the following is responsible for the falling (repolarizing)phase of the action potential?

A)Voltage-gated Na⁺ channels are opened
B)The Na⁺, K⁺ pump restores the ions to their original locations inside and outside of the cell
C)The permeability to Na⁺ increases greatly
D)ATPase destroys the energy supply that was maintaining the action potential at its peak
E)The permeability to K⁺ increases greatly while that to Na⁺ decreases

Question 39

Which of the following statements concerning the rate of action potential propagation is true?

A)It is faster in large-diameter axons than in small-diameter ones
B)It is faster for a strong stimulus than for a weak one
C)It is faster in myelinated nerve fibers than in nonmyelinated ones
D)Both it is faster in large-diameter axons than in small-diameter ones and it is faster in myelinated nerve fibers than in nonmyelinated ones are true
E)All of the choices are true

Question 40

An action potential in a neuronal membrane differs from a graded potential in that

A)An action potential requires the opening of Ca⁺² channels, whereas a graded potential does not
B)An action potential is propagated without decrement, whereas a graded potential is not
C)An action potential has a threshold and is an all-or-none phenomenon, whereas a graded potential does not have a threshold and is not all-or-none
D)Both an action potential requires the opening of Ca⁺² channels, whereas a graded potential does not and an action potential is propagated without decrement, whereas a graded potential is not are correct
E)Both an action potential is propagated without decrement, whereas a graded potential is not and an action potential has a threshold and is an all-or-none phenomenon, whereas a graded potential does not have a threshold and is not all-or-none are correct

Question 41

A presynaptic synapse

A)Is a synapse between an axon terminal and a dendrite
B)Is a synapse between axons
C)May be either stimulatory or inhibitory
D)Both is a synapse between an axon terminal and a dendrite and may be either stimulatory or inhibitory are correct
E)Both is a synapse between axons and may be either stimulatory or inhibitory are correct

Question 42

An inhibitory postsynaptic potential

A)Is produced by an increased permeability to both Na⁺ and K⁺
B)Is produced by an increased permeability to Cl^- and/or K⁺
C)Is a small depolarization in a postsynaptic cell
D)Can be summed with other IPSPs to trigger an action potential in the postsynaptic cell
E)Both is produced by an increased permeability to both Na⁺ and K⁺ and can be summed with other IPSPs to trigger an action potential in the postsynaptic cell are correct

Question 43

Which of the following statements about EPSPs is false?

A)They are produced by the opening of chemically regulated sodium channels
B)They can be conducted only a short distance
C)They are depolarizing
D)They are able to summate
E)Their amplitude is all-or-none

Question 44

The role of calcium ion at chemical synapses is to

A)Depolarize the axon terminal of the presynaptic cell
B)Bind to neurotransmitter receptors on the postsynaptic cell
C)Cause fusion of synaptic vesicles with the plasma membrane of the axon terminal
D)Interfere with IPSPs in the postsynaptic cell
E)All of the choices are correct

Question 45

At an excitatory synapse,

A)There is increased permeability of the postsynaptic cell to both Na⁺ and K⁺
B)A small hyperpolarization occurs
C)An action potential in the presynaptic neuron always causes an action potential in the postsynaptic neuron
D)Both there is increased permeability of the postsynaptic cell to both Na⁺ and K⁺ and a small hyperpolarization occurs are correct
E)None of the choices are correct

Question 46

Temporal summation on a postsynaptic membrane

A)Refers to the effect on the membrane of one (or more) synaptic event before the effects of a previous synaptic event have died away
B)Refers only to addition of EPSPs
C)Refers only to the effect of stimulating different synapses repeatedly
D)Inevitably leads to action potentials in the axon
E)Is described by none of these choices

Question 47

Which of the following neurotransmitters is secreted by adrenergic neurons?

A)Acetylcholine
B)Dopamine
C)Endorphins
D)Norepinephrine
E)All of the choices are correct

Question 48

Acetylcholine is the neurotransmitter for

A)Preganglionic sympathetic neurons
B)Postganglionic sympathetic neurons
C)Motor neurons
D)Preganglionic sympathetic neurons and postganglionic sympathetic neurons
E)Preganglionic sympathetic neurons and motor neurons

Question 49

Exocytosis of neurotransmitter into the synaptic cleft is triggered by an influx of ______ in response to the arrival of an action potential in the axon terminal.

A)K⁺
B)Na⁺
C)Ca2⁺
D)ATP
E)Cl^-

Question 50

Which of the following statements regarding neurotransmitters is true?

A)Acetylcholine is broken down by enzymes present on postsynaptic cell membranes
B)Acetylcholine that is released at synapses binds to adrenergic receptors in the postsynaptic cell membrane
C)Catecholamines are the most abundant neurotransmitters in the central nervous system
D)Opiate drugs, such as morphine, are antagonists of a class of neurotransmitters called endorphins
E)Gamma-aminobutyric acid (GABA) is a major excitatory transmitter in the central nervous system

Question 51

A postsynaptic neuron has three presynaptic inputs - from neurons X,Y and Z.When X and Y are stimulated simultaneously and repeatedly,the postsynaptic neuron reaches threshold and undergoes an action potential.When X and Z are stimulated simultaneously,however,there is no change in the membrane potential of the postsynaptic neuron.The simultaneous stimulation of X and Y is an example of

A)Temporal summation
B)Presynaptic inhibition
C)Spatial summation
D)Neuronal divergence
E)None of the choices are correct

Question 52

Which of the following statements about norepinephrine is not correct?

A)Norepinephrine is a neurotransmitter
B)Norepinephrine binds to adrenergic receptors
C)Norepinephrine binds to catecholaminergic receptors
D)Dopamine is a precursor to norepinephrine
E)Epinephrine is a precursor to norepinephrine

Question 53

Which of the following is not known to be an important neurotransmitter in the CNS?

A)Dopamine
B)Acetylcholine
C)Morphine
D)Glutamate
E)Substance P

Question 54

An EPSP in a membrane

A)Is a direct result of the opening of ligand-sensitive channels for Na⁺ and K⁺ ions in the membrane
B)Is a direct result of the opening of voltage-gated channels for Na⁺ and K⁺ ions in the membrane
C)Stabilizes the membrane to remain at its resting potential
D)Both is a direct result of the opening of ligand-sensitive channels for Na⁺ and K⁺ ions in the membrane and stabilizes the membrane to remain at its resting potential are correct
E)Both is a direct result of the opening of voltage-gated channels for Na⁺ and K⁺ ions in the membrane and stabilizes the membrane to remain at its resting potential are correct

Question 55

A postsynaptic neuron has three presynaptic inputs - from neurons X,Y and Z.When X and Y are stimulated simultaneously and repeatedly,the postsynaptic neuron reaches threshold and undergoes an action potential.When X and Z are stimulated simultaneously,however,there is no change in the membrane potential of the postsynaptic neuron.What can you tell about presynaptic neurons Y and Z?

A)They are probably both excitatory
B)They are probably both inhibitory
C)Y is probably excitatory and Z is probably inhibitory
D)Z is probably excitatory and Y is probably inhibitory

Question 56

Which of the following statements about acetylcholine is correct?

A)Acetylcholine binds to cholinergic receptors
B)Acetylcholine binds to nicotinic and muscarinic receptors
C)Acetylcholine synthesis is catalyzed by acetylcholinesterase
D)Both acetylcholine binds to cholinergic receptors and acetylcholine binds to nicotinic and muscarinic receptors are correct
E)Both acetylcholine binds to cholinergic receptors and acetylcholine synthesis is catalyzed by acetylcholinesterase are correct

Question 57

Neuron X makes inhibitory axon-axon synaptic contact with neuron Y at the synapse of Y and neuron Z.Stimulation of action potentials in X

A)Will inhibit propagation of action potentials in Y
B)Inhibit release of neurotransmitter by Y
C)Make the Y-Z synapse more effective (i.e., increase the size of the postsynaptic potential in Z)
D)Both will inhibit propagation of action potentials in Y and inhibit release of neurotransmitter by Y are correct
E)None of the choices are correct

Question 58

Interneurons are said to function as integrators of information because they

A)Receive synaptic input from many other neurons
B)Sum excitatory and inhibitory synaptic input
C)Are presynaptic to many other neurons
D)Both receive synaptic input from many other neurons and sum excitatory and inhibitory synaptic input are correct
E)All of the choices are correct

Question 59

The regions of axon membrane that lie between regions of myelin are the

A)Islets of Langerhans
B)Nodes of Ranvier
C)Synaptic membranes
D)Glial cells
E)Dendrites

Question 60

The significance of the initial segment of axons is that

A)Its threshold potential is higher than that of the cell body and dendrites
B)Its threshold potential is lower than that of the cell body and dendrites
C)Synapses close to it are more effective in influencing whether an action potential will be generated in that axon than are synapses farther away from the initial segment
D)Both its threshold potential is higher than that of the cell body and dendrites and synapses close to it are more effective in influencing whether an action potential will be generated in that axon than are synapses farther away from the initial segment are correct
E)Both its threshold potential is lower than that of the cell body and dendrites and synapses close to it are more effective in influencing whether an action potential will be generated in that axon than are synapses farther away from the initial segment are correct

Question 61

Nicotine is

A)A cholinergic antagonist
B)A beta-adrenergic agonist
C)A cholinergic agonist
D)An alpha-adrenergic antagonist
E)A neurotransmitter

Question 62

Drug X interferes with the action of norepinephrine at synapses.Which of the following mechanisms would not explain the effects of X?

A)X inhibits synthesis of norepinephrine at the axon terminal
B)X inhibits norepinephrine release from the terminal
C)X blocks reuptake of norepinephrine by the terminal
D)X is a norepinephrine antagonist
E)X stimulates the catabolism of norepinephrine

Question 63

Synthesis of neuropeptides differs from that of other neurotransmitters because it

A)Takes place in the axon terminals of neurons
B)Takes place in the cell bodies of neurons
C)Involves synthesis of precursor molecules
D)Both takes place in the axon terminals of neurons and involves synthesis of precursor molecules are correct
E)Both takes place in the cell bodies of neurons and involves synthesis of precursor molecules are correct

Question 64

Serotonin

A)Is a neuromodulator
B)Facilitates incoming sensory stimuli in the CNS
C)Activity in the brain is highest during sleep
D)Both is a neuromodulator and facilitates incoming sensory stimuli in the CNS are correct
E)Both is a neuromodulator and activity in the brain is highest during sleep are correct

Question 65

The region of the brain most closely associated with homeostasis and survival of the individual is

A)The thalamus
B)The hippocampus
C)The cerebrum
D)The cerebellum
E)The hypothalamus

Question 66

The reticular formation of the brain

A)Is part of the cerebellum
B)Is essential for life
C)Sends and receives information from all regions of the CNS
D)Both is part of the cerebellum and sends and receives information from all regions of the CNS are correct
E)Both is essential for life and sends and receives information from all regions of the CNS are correct

Question 67

Which of the following is not true of neuromodulators? They may

A)Influence synaptic effectiveness
B)Act through second messengers
C)Be released with neurotransmitters
D)Be the same molecules as neurotransmitters
E)Be none of the choices

Question 68

Which of the following drugs would not enhance the activity of serotoninergic neurons?

A)A drug that increases the uptake of tryptophan into neurons
B)A drug that inhibits enzymes that break down serotonin
C)A drug that facilitates reuptake of serotonin by serotoninergic neurons
D)A drug that up-regulates serotonin receptors

Question 69

The central nervous system includes the

A)Afferent nerves and spinal cord
B)Efferent nerves and spinal cord
C)Autonomic nervous system and the brain
D)Brain stem and the autonomic nervous system
E)Brain and spinal cord

Question 70

One of the most abundant excitatory neurotransmittors in the CNS is

A)Glutamate
B)Dopamine
C)Norepinephrine
D)Gamma-aminobutyric acid (GABA)
E)Endorphin

Question 71

The binding of nicotine with nicotinic acetylcholine receptors can trigger each of the following effects,except

A)A mild form of skeletal muscle paralysis to create a more relaxed state
B)Mediation of signal transmission at neuromuscular junctions
C)Generation of excitatory signals within autonomic ganglia
D)The release of norepinephrine, dopamine and epinephrine
E)Facilitation of the release of multiple neurotransmitters within the brain, including the "reward pathway" involving dopamine

Question 72

Glial cells

A)Help to form the blood-brain barrier
B)Outnumber neurons in the central nervous system
C)Form the myelin sheath of neuronal axons
D)Both help to form the blood-brain barrier and outnumber neurons in the central nervous system are correct
E)All of the choices are correct

Question 73

Which of the following enzymes is/are important for the metabolism of catecholamines?

A)Tyrosine hydroxylase
B)Monoamine oxidase
C)Acetylcholinesterase
D)Both tyrosine hydroxylase and monoamine oxidase are correct
E)All of the choices are correct

Question 74

One of the major inhibitory neurotransmittors in the CNS is

A)Glutamate
B)Dopamine
C)Norepinephrine
D)Gamma-aminobutyric acid (GABA)
E)Beta-endorphin

Question 75

The limbic system is

A)Composed of several parts of the diencephalon and cerebrum
B)Composed of white and gray matter
C)Associated with emotional responses and learning
D)Composed of several parts of the diencephalon and cerebrum and associated with emotional responses and learning
E)All of the choices are correct

Question 76

The major known classes of neurotransmitters and/or neuromodulators include each of the following except

A)Amino acids
B)Cyclic nucleotides
C)Neuropeptides
D)ACh
E)Biogenic amines

Question 77

The portion of the peripheral nervous system that is composed of nerve fibers that innervate skeletal muscle is the

A)Afferent nervous system
B)Sympathetic nervous system
C)Parasympathetic nervous system
D)Somatic motor nervous system
E)Autonomic nervous system

Question 78

Alzheimer's disease is thought to involve primarily

A)Loss of neurons that secrete or respond to catecholamines
B)Loss of adrenergic neurons
C)Loss of cholinergic neurons
D)Loss of neurons that secrete or respond to dopamine
E)The inevitable loss of brain function with aging

Question 79

The cerebellum

A)Is important for coordinating body movement
B)Has a cortex
C)Is part of the brain stem
D)Both is important for coordinating body movement and has a cortex are correct
E)All of the choices are correct

Question 80

Which of the following kinds of neurons are not cholinergic?

A)Motor neurons
B)Postganglionic sympathetic neurons
C)Postganglionic parasympathetic neurons
D)Preganglionic sympathetic neurons
E)Preganglionic parasympathetic neurons