Vanders Human Physiology The Mechanisms of Body Function 12th Edition By Widmaier – Test Bank

Vanders Human Physiology The Mechanisms of Body Function 12th Edition By Widmaier – Test Bank

Chapter 06
Neuronal Signaling and the Structure of the Nervous System

Multiple Choice Questions

1. 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

Bloom’s Level: 1. Remember
Section 6A
Topic: Nervous System

2. 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

Bloom’s Level: 1. Remember
Section 6A.01
Topic: Nervous System

3. 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

Bloom’s Level: 1. Remember
Section 6A.01
Topic: Nervous System

4. 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

Bloom’s Level: 1. Remember
Section 6A.02
Topic: Nervous System

5. 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

Bloom’s Level: 1. Remember
Section 6A.03
Topic: Nervous System

6. 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

Bloom’s Level: 1. Remember
Section 6B.01
Topic: Nervous System

7. 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

Bloom’s Level: 1. Remember
Section 6B.01
Topic: Nervous System

8. 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

Bloom’s Level: 2. Understand
Section 6B.02
Topic: Nervous System

9. 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

Bloom’s Level: 2. Understand
Section 6B.02
Topic: Nervous System

10. 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

Bloom’s Level: 1. Remember
Section 6B.02
Topic: Nervous System

11. 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

Bloom’s Level: 1. Remember
Section 6B.02
Topic: Nervous System

12. 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

Bloom’s Level: 1. Remember
Section 6B.02
Topic: Nervous System

13. 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

Bloom’s Level: 1. Remember
Section 6B.02
Topic: Nervous System

14. 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

Bloom’s Level: 3. Apply
Section 6B.02
Topic: Nervous System

15. 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

Bloom’s Level: 3. Apply
Section 6B.02
Topic: Nervous System

16. 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

Bloom’s Level: 1. Remember
Section 6B.02
Topic: Nervous System

17. 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

Bloom’s Level: 3. Apply
Section 6B.02
Topic: Nervous System

18. 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

Bloom’s Level: 2. Understand
Section 6B.02
Topic: Nervous System

19. 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

Bloom’s Level: 2. Understand
Section 6B.02
Topic: Nervous System

20. 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

Bloom’s Level: 1. Remember
Section 6B.02
Topic: Nervous System

21. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

22. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

23. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

24. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

25. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

26. 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

Bloom’s Level: 2. Understand
Section 6B.03
Topic: Nervous System

27. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

28. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

29. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

30. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

31. 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

Bloom’s Level: 2. Understand
Section 6B.03
Topic: Nervous System

32. 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

Bloom’s Level: 2. Understand
Section 6B.03
Topic: Nervous System

33. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

34. 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

Bloom’s Level: 2. Understand
Section 6B.03
Topic: Nervous System

35. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

36. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

37. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

38. 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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

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

Bloom’s Level: 1. Remember
Section 6B.03
Topic: Nervous System

40. 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

Bloom’s Level: 2. Understand
Section 6B.03
Topic: Nervous System

41. 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

Bloom’s Level: 1. Remember
Section 6A.01
Topic: Nervous System

42. 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

Bloom’s Level: 1. Remember
Section 6A.02
Topic: Nervous System