Question 1

Refer to the figure shown.
  _______ channels are responsible for the undershoot at point D of the figure.

Accepted Answer

A)  Voltage-gated sodium 
B)  Voltage-gated potassium 
C)  Ligand-gated potassium 
D)  Voltage-gated calcium 
A)  Voltage-gated sodium 
B)  Voltage-gated potassium 
C)  Ligand-gated potassium 
D)  Voltage-gated calcium B

Question 2

Which arrow best represents the point where permeability to sodium is the highest?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
A)  I 
B)  II 
C)  III 
D)  IV A

Question 3

Which statement regarding the ions in intracellular and extracellular fluids in a standard animal cell is true?

Accepted Answer

A)  Na+ leaks into the cell rapidly because its electrochemical gradient is large. 
B)  K+ leaks out of the cell slowly because the electrochemical gradient is small. 
C)  Cl- leaks into the cell rapidly because its electrochemical gradient is large. 
D)  Negatively charged proteins leak out of the cell slowly because their electrochemical gradient is small. 
A)  Na+ leaks into the cell rapidly because its electrochemical gradient is large. 
B)  K+ leaks out of the cell slowly because the electrochemical gradient is small. 
C)  Cl- leaks into the cell rapidly because its electrochemical gradient is large. 
D)  Negatively charged proteins leak out of the cell slowly because their electrochemical gradient is small. B

Question 4

Which statement about a local circuit in an axon is false?

Accepted Answer

A)  Ions flow in intracellular fluid, carrying current to more distant parts of the membrane. 
B)  At the membrane, the ion movements change the distribution of charges on the membrane capacitance. 
C)  An ionic current completes the local circuit as cations move toward the locus of the action potential and anions move away. 
D)  Anions migrate into the membrane interior. 
A)  Ions flow in intracellular fluid, carrying current to more distant parts of the membrane. 
B)  At the membrane, the ion movements change the distribution of charges on the membrane capacitance. 
C)  An ionic current completes the local circuit as cations move toward the locus of the action potential and anions move away. 
D)  Anions migrate into the membrane interior.

Question 5

During the falling phase of an action potential, the K+ leak channel on the axon is _______, the voltage-gated Na+ channel is _______, and the voltage-gated K+ channel is _______.

Accepted Answer

A)  open; inactivated; closed 
B)  closed; inactivated; closed 
C)  open; inactivated; open 
D)  open; closed; closed 
A)  open; inactivated; closed 
B)  closed; inactivated; closed 
C)  open; inactivated; open 
D)  open; closed; closed

Question 6

Refer to the figure shown.
  If stimulating current pulse 9 (not shown) was both stronger and longer than stimulating current pulse 8, then

Accepted Answer

A)  the train of action potentials would continue for the length of the stimulating current. 
B)  action potentials would increase in amplitude. 
C)  action potentials would first increase in frequency and then decrease. 
D)  the line at stimulus 9 would look exactly same as the line at stimulus 8. 
A)  the train of action potentials would continue for the length of the stimulating current. 
B)  action potentials would increase in amplitude. 
C)  action potentials would first increase in frequency and then decrease. 
D)  the line at stimulus 9 would look exactly same as the line at stimulus 8.

Question 7

The cablelike processes that convey electrical signals rapidly and faithfully from place to place in the body are called

Accepted Answer

A)  cell bodies 
B)  dendrites 
C)  action potentials 
D)  axons 
A)  cell bodies 
B)  dendrites 
C)  action potentials 
D)  axons

Question 8

Considering neurons in living systems, which variable affects conduction velocity the most?

Accepted Answer

A)  Myelination 
B)  Temperature 
C)  Length 
D)  Diameter 
A)  Myelination 
B)  Temperature 
C)  Length 
D)  Diameter

Question 9

Refer to the figure shown.
  The figure depicts a

Accepted Answer

A)  neuronal action potential. 
B)  cardiac action potential. 
C)  pacemaker potential. 
D)  graded potential. 
A)  neuronal action potential. 
B)  cardiac action potential. 
C)  pacemaker potential. 
D)  graded potential.

Question 10

A spiking neuron and a nonspiking neuron share which characteristic?

Accepted Answer

A)  High concentration of voltage-gated Na+ channels at the axon hillock 
B)  A graded potential down the entire length of the axon 
C)  An action potential down the entire length of the axon 
D)  Neurotransmitter secretion based on a change in membrane potential 
A)  High concentration of voltage-gated Na+ channels at the axon hillock 
B)  A graded potential down the entire length of the axon 
C)  An action potential down the entire length of the axon 
D)  Neurotransmitter secretion based on a change in membrane potential

Question 11

Refer to the figure shown.
  In the lower panel, the difference between the dashed line and the solid red line is due to

Accepted Answer

A)  membrane resistance. 
B)  the fact that one represents a depolarization and the other represents a hyperpolarization. 
C)  the capacitive properties of the membrane. 
D)  the difference in applied voltage. 
A)  membrane resistance. 
B)  the fact that one represents a depolarization and the other represents a hyperpolarization. 
C)  the capacitive properties of the membrane. 
D)  the difference in applied voltage.

Question 12

What are the similarities and differences among the channels in the voltage-gated channel superfamily?

Accepted Answer

All the voltage-gated channels have prin

Question 13

How do nonspiking neurons function even though their depolarization signal significantly degrades with distance?

Accepted Answer

A)  Voltage-gated Na+ channels are replaced by ligand-gated Na+ channels. 
B)  These neurons are very short, so there is no major signal decrement. 
C)  There are sufficient numbers of voltage-gated Na+ channels to convey the signal without major decrement. 
D)  Voltage-gated K+ channels compensate for the lack of voltage-gated Na+ channels. 
A)  Voltage-gated Na+ channels are replaced by ligand-gated Na+ channels. 
B)  These neurons are very short, so there is no major signal decrement. 
C)  There are sufficient numbers of voltage-gated Na+ channels to convey the signal without major decrement. 
D)  Voltage-gated K+ channels compensate for the lack of voltage-gated Na+ channels.

Question 14

According to the Goldman equation, the contribution of each ion to the membrane potential depends most on

Accepted Answer

A)  its size. 
B)  its membrane permeability. 
C)  its activation energy. 
D)  the resting membrane potential. 
A)  its size. 
B)  its membrane permeability. 
C)  its activation energy. 
D)  the resting membrane potential.

Question 15

In a cell, the difference in ion concentration between the intracellular and extracellular fluids results from

Accepted Answer

A)  active ion transport. 
B)  passive diffusion of ions. 
C)  bulk movements of intracellular and extracellular fluids. 
D)  both active ion transport and passive diffusion of ions. 
A)  active ion transport. 
B)  passive diffusion of ions. 
C)  bulk movements of intracellular and extracellular fluids. 
D)  both active ion transport and passive diffusion of ions.

Question 16

For an axon at resting membrane potential, the K+ leak channel is _______, the voltage-gated Na+ channel is _______, and the voltage-gated K+ channel is _______.

Accepted Answer

A)  open; inactivated; closed 
B)  closed; inactivated; closed 
C)  open; inactivated; open 
D)  open; closed; closed 
A)  open; inactivated; closed 
B)  closed; inactivated; closed 
C)  open; inactivated; open 
D)  open; closed; closed

Question 17

Refer to the figure shown.
  The properties shown in the figure can be measured in

Accepted Answer

A)  neurons. 
B)  neurons and pacemaker cells. 
C)  muscle cells. 
D)  neurons, pacemaker cells, and muscle cells 
A)  neurons. 
B)  neurons and pacemaker cells. 
C)  muscle cells. 
D)  neurons, pacemaker cells, and muscle cells

Question 18

Compare and contrast current and voltage with respect to the cell membrane.

Accepted Answer

The net movement of charge constitutes a

Question 19

Refer to the figure shown.
  On the figure, I represents _______ currents through voltage-gated _______ channels.

Accepted Answer

A)  outward; Na+ 
B)  inward; Na+ 
C)  outward; K+ 
D)  inward; K+ 
A)  outward; Na+ 
B)  inward; Na+ 
C)  outward; K+ 
D)  inward; K+

Question 20

Refer to the figure shown.
  Which technique was used to collect the data in the bottom panel?

Accepted Answer

A)  Patch-clamp 
B)  Voltage-clamp 
C)  Current-clamp 
D)  Hodgkin clamp 
A)  Patch-clamp 
B)  Voltage-clamp 
C)  Current-clamp 
D)  Hodgkin clamp

Exam 12: Neurons

Refer to the figure shown. _______ channels are responsible for the undershoot at point D of the figure.

Which arrow best represents the point where permeability to sodium is the highest?

Which statement regarding the ions in intracellular and extracellular fluids in a standard animal cell is true?

Which statement about a local circuit in an axon is false?

During the falling phase of an action potential, the K+ leak channel on the axon is _______, the voltage-gated Na+ channel is _______, and the voltage-gated K+ channel is _______.

Refer to the figure shown. If stimulating current pulse 9 (not shown) was both stronger and longer than stimulating current pulse 8, then

The cablelike processes that convey electrical signals rapidly and faithfully from place to place in the body are called

Considering neurons in living systems, which variable affects conduction velocity the most?

Refer to the figure shown. The figure depicts a

A spiking neuron and a nonspiking neuron share which characteristic?

Refer to the figure shown. In the lower panel, the difference between the dashed line and the solid red line is due to

What are the similarities and differences among the channels in the voltage-gated channel superfamily?

How do nonspiking neurons function even though their depolarization signal significantly degrades with distance?

According to the Goldman equation, the contribution of each ion to the membrane potential depends most on

In a cell, the difference in ion concentration between the intracellular and extracellular fluids results from

For an axon at resting membrane potential, the K+ leak channel is _______, the voltage-gated Na+ channel is _______, and the voltage-gated K+ channel is _______.

Refer to the figure shown. The properties shown in the figure can be measured in

Compare and contrast current and voltage with respect to the cell membrane.

Refer to the figure shown. On the figure, I represents _______ currents through voltage-gated _______ channels.

Refer to the figure shown. Which technique was used to collect the data in the bottom panel?

Animals and Environments: Function on the Ecological Stage

Molecules and Cells in Animal Physiology

Genomics, Proteomics, and Related Approaches to Physiology

Physiological Development and Epigenetics

Transport of Solutes and Water

Nutrition, Feeding, and Digestion

Energy Metabolism

Aerobic and Anaerobic Forms of Metabolism

The Energetics of Aerobic Activity

Thermal Relations

Food, Energy, and Temperature at Work: The Lives of Mammals in Frigid Places

Synapses

Sensory Processes

Nervous System Organization and Biological Clocks

Endocrine and Neuroendocrine Physiology

Reproduction

Integrating Systems at Work: Animal Navigation

Control of Movement

Muscle

Movement and Muscle at Work: Plasticity in Response to Use and Disuse

Introduction to Oxygen and Carbon Dioxide in Physiology

External Respiration: the Physiology of Breathing

Transport of Oxygen and Carbon Dioxide in Body Fluids With an Introduction to Acid- Base Physiology

Circulation

Oxygen, Carbon Dioxide, and Internal Transport at Work: Diving by Marine Mammals

Water and Salt Physiology: Introduction and Mechanisms

Kidneys and Excretion With Notes on Nitrogen Excretion

Water, Salts, and Excretion at Work: Mammals of Deserts and Dry Savannas

Water and Salt Physiology of Animals in Their Environments

Filters

During the falling phase of an action potential, the K⁺ leak channel on the axon is ___, the voltage-gated Na⁺ channel is _, and the voltage-gated K⁺ channel is _____.

For an axon at resting membrane potential, the K⁺ leak channel is ___, the voltage-gated Na⁺ channel is _, and the voltage-gated K⁺ channel is _____.

Refer to the figure shown. On the figure, I represents _ currents through voltage-gated _ channels.