Question 1

The channelopathy known as QT syndrome is a result of mutation in ________ channels.

Accepted Answer

A)  sodium 
B)  potassium 
C)  calcium 
D)  chloride 
E)  sodium, potassium, or calcium 
A)  sodium 
B)  potassium 
C)  calcium 
D)  chloride 
E)  sodium, potassium, or calcium

Question 2

Presynaptic facilitation occurs when

Accepted Answer

A)  extracellular concentration of sodium increases. 
B)  extracellular concentration of potassium increases. 
C)  calcium channels in the presynaptic membrane are inhibited. 
D)  calcium channels in the presynaptic membrane remain open longer. 
E)  temporal summation occurs. 
A)  extracellular concentration of sodium increases. 
B)  extracellular concentration of potassium increases. 
C)  calcium channels in the presynaptic membrane are inhibited. 
D)  calcium channels in the presynaptic membrane remain open longer. 
E)  temporal summation occurs.

Question 3

Match the type of signal to its description (answers may be used more than once).
-size increases if stimulus strength increases

Accepted Answer

A) graded potential 
B) action potential 
C) both 
A) graded potential 
B) action potential 
C) both

Question 4

Explain the differences in axon regeneration in the CNS and PNS,and the implications for recovery from injury.What experiments might scientists try based on these differences?

Accepted Answer

Schwann cells,present in the PNS but not

Question 5

What stops the rising phase of the action potential?

Accepted Answer

A)  The K+ gate closes. 
B)  The Na+ activation gate opens. 
C)  The Na+ inactivation gate closes. 
D)  The Na+ inactivation gate opens. 
E)  The sodium activation gate closes. 
A)  The K+ gate closes. 
B)  The Na+ activation gate opens. 
C)  The Na+ inactivation gate closes. 
D)  The Na+ inactivation gate opens. 
E)  The sodium activation gate closes.

Question 6

Exocrine glands,smooth muscles,and cardiac muscles are controlled by the

Accepted Answer

A)  central nervous system. 
B)  autonomic nervous system. 
C)  somatic motor division. 
D)  peripheral nervous system. 
E)  enteric nervous system. 
A)  central nervous system. 
B)  autonomic nervous system. 
C)  somatic motor division. 
D)  peripheral nervous system. 
E)  enteric nervous system.

Question 7

The point during an action potential when the inside of the cell has become more positive than the outside is known as the

Accepted Answer

A)  depolarization. 
B)  rising phase. 
C)  falling phase. 
D)  overshoot. 
E)  peak. 
A)  depolarization. 
B)  rising phase. 
C)  falling phase. 
D)  overshoot. 
E)  peak.

Question 8

Branches that sometimes occur along the length of an axon are called

Accepted Answer

A)  dendrites. 
B)  axon terminals. 
C)  collaterals. 
D)  axon hillocks. 
E)  synapses. 
A)  dendrites. 
B)  axon terminals. 
C)  collaterals. 
D)  axon hillocks. 
E)  synapses.

Question 9

Match the term with its description (answers may be used more than once).
-cells in the CNS that form myelin

Accepted Answer

A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia 
A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia

Question 10

Neurotransmitter is stored and released from

Accepted Answer

A)  axon terminals only. 
B)  axon varicosities only. 
C)  dendritic spines only. 
D)  cell bodies only. 
E)  axon terminals and axon varicosities. 
A)  axon terminals only. 
B)  axon varicosities only. 
C)  dendritic spines only. 
D)  cell bodies only. 
E)  axon terminals and axon varicosities.

Question 11

The major determinant of the resting potential of all cells is

Accepted Answer

A)  Ca2+ concentration in the blood and interstitial fluid. 
B)  Na+ concentration in the blood and interstitial fluid. 
C)  K+ gradient between the blood and interstitial fluid. 
D)  K+ concentration inside cells. 
E)  Na+ concentration inside cells. 
A)  Ca2+ concentration in the blood and interstitial fluid. 
B)  Na+ concentration in the blood and interstitial fluid. 
C)  K+ gradient between the blood and interstitial fluid. 
D)  K+ concentration inside cells. 
E)  Na+ concentration inside cells.

Question 12

In order for a synapse to be an effective means of cellular communication,slow removal or inactivation of neurotransmitter molecules from the synapse is important.

Accepted Answer

A) True 
 B)False

Question 13

If the graded potential increases in amplitude,then the frequency of the action potentials fired also increases.

Accepted Answer

A) True 
 B)False

Question 14

Once the action potential reaches the axon terminal,what happens next?

Accepted Answer

A)  exocytosis of a neurocrine 
B)  release of the neurotransmitter into the synaptic cleft 
C)  release of a neurohormone into the blood 
D)  Any of the above could happen next. 
A)  exocytosis of a neurocrine 
B)  release of the neurotransmitter into the synaptic cleft 
C)  release of a neurohormone into the blood 
D)  Any of the above could happen next.

Question 15

When two or more graded potentials arrive at the trigger zone,which of the following could happen?

Accepted Answer

A)  An excitatory and inhibitory signal can cancel each other out. 
B)  Two excitatory stimuli may be additive, and summation could occur. 
C)  Two inhibitory stimuli may be additive, resulting in lower excitability. 
D)  An excitatory and inhibitory signal can cancel each other out and two excitatory stimuli may be additive, and summation could occur. 
E)  An excitatory and inhibitory signal can cancel each other out; two excitatory stimuli may be additive, and summation could occur; and two inhibitory stimuli may be additive, resulting in lower excitability. 
A)  An excitatory and inhibitory signal can cancel each other out. 
B)  Two excitatory stimuli may be additive, and summation could occur. 
C)  Two inhibitory stimuli may be additive, resulting in lower excitability. 
D)  An excitatory and inhibitory signal can cancel each other out and two excitatory stimuli may be additive, and summation could occur. 
E)  An excitatory and inhibitory signal can cancel each other out; two excitatory stimuli may be additive, and summation could occur; and two inhibitory stimuli may be additive, resulting in lower excitability.

Question 16

When two or more graded potentials arrive at the trigger zone within a short period of time,their effects are additive and ________ occurs.

Accepted Answer

The answer of When two or more graded potentials arrive...

Question 17

The cell body of neurons is generally

Accepted Answer

A)  90% of the cell volume. 
B)  50% of the cell volume. 
C)  10% of the cell volume. 
D)  found in the same position on every neuron. 
A)  90% of the cell volume. 
B)  50% of the cell volume. 
C)  10% of the cell volume. 
D)  found in the same position on every neuron.

Question 18

If a hyperpolarizing graded potential and a depolarizing graded potential of similar magnitudes arrive at the trigger zone at the same time,what is most likely to occur?

Accepted Answer

A)  An action potential is fired off more quickly than usual. 
B)  Nothing. They will cancel each other out. 
C)  The cell becomes hyperpolarized. 
D)  The cell becomes easier to excite. 
E)  The cell dies. 
A)  An action potential is fired off more quickly than usual. 
B)  Nothing. They will cancel each other out. 
C)  The cell becomes hyperpolarized. 
D)  The cell becomes easier to excite. 
E)  The cell dies.

Question 19

Match the term with its description (answers may be used more than once).
-cells that myelinate only one axon each; multiple cells per axon

Accepted Answer

A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia 
A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia

Question 20

Ion concentrations are first significantly affected after ________ action potential(s).

Accepted Answer

A)  one 
B)  a few dozen 
C)  a few hundred 
D)  a few thousand 
E)  a few million 
A)  one 
B)  a few dozen 
C)  a few hundred 
D)  a few thousand 
E)  a few million

Exam 8: Neurons: Cellular and Network Properties

The channelopathy known as QT syndrome is a result of mutation in ________ channels.

Presynaptic facilitation occurs when

Match the type of signal to its description (answers may be used more than once). -size increases if stimulus strength increases

Explain the differences in axon regeneration in the CNS and PNS,and the implications for recovery from injury.What experiments might scientists try based on these differences?

What stops the rising phase of the action potential?

Exocrine glands,smooth muscles,and cardiac muscles are controlled by the

The point during an action potential when the inside of the cell has become more positive than the outside is known as the

Branches that sometimes occur along the length of an axon are called

Match the term with its description (answers may be used more than once). -cells in the CNS that form myelin

Neurotransmitter is stored and released from

The major determinant of the resting potential of all cells is

In order for a synapse to be an effective means of cellular communication,slow removal or inactivation of neurotransmitter molecules from the synapse is important.

If the graded potential increases in amplitude,then the frequency of the action potentials fired also increases.

Once the action potential reaches the axon terminal,what happens next?

When two or more graded potentials arrive at the trigger zone,which of the following could happen?

When two or more graded potentials arrive at the trigger zone within a short period of time,their effects are additive and ________ occurs.

The cell body of neurons is generally

If a hyperpolarizing graded potential and a depolarizing graded potential of similar magnitudes arrive at the trigger zone at the same time,what is most likely to occur?

Match the term with its description (answers may be used more than once). -cells that myelinate only one axon each; multiple cells per axon

Ion concentrations are first significantly affected after ________ action potential(s).

Introduction to Physiology

Molecular Interactions

Compartmentation: Cells and Tissues

Energy and Cellular Metabolism

Membrane Dynamics

Communication, Integration, and Homeostasis

Introduction to the Endocrine System

The Central Nervous System

Sensory Physiology

Efferent Division: Autonomic and Somatic Motor Control

Muscles

Integrative Physiology I: Control of Body Movement

Cardiovascular Physiology

Blood Flow and the Control of Blood Pressure

Blood

Mechanics of Breathing

Gas Exchange and Transport

The Kidneys

Integrative Physiology II: Fluid and Electrolyte Balance

The Digestive System

Metabolism and Energy Balance

Endocrine Control of Growth and Metabolism

The Immune System

Integrative Physiology III: Exercise

Reproduction and Development

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