Question 1

In what way is a myelinated axon that has lost its myelin (through disease)  different from an axon that was never myelinated?

Accepted Answer

A)   It has a smaller diameter.
B)   It lacks sodium gates along parts of its surface.
C)   It has a longer refractory period.
D)   It has a much higher threshold.E) A) and D)
F) A) and C)

Question 2

The action potential of a neuron depends mostly on what movement of ions?

Accepted Answer

A)   sodium ions entering the cell
B)   sodium ions leaving the cell
C)   potassium ions entering the cell
D)   potassium ions leaving the cellE) B) and C)
F) A) and C)

Question 3

A neuron can have any number of ____, but no more than one ____.

Accepted Answer

A)   dendrites; axon
B)   axons; dendrite
C)   cell bodies; axon
D)   cell bodies; dendriteE) A) and D)
F) A) and C)

Question 4

If all of a neuron's dendrites or axons were contained within the spinal cord, it would be considered a(n)  ____ neuron.

Accepted Answer

A)   efferent
B)   afferent
C)   intrinsic
D)   PurkinjeE) A) and D)
F) A) and B)

Question 5

The membrane of a neuron is specialized to:

Accepted Answer

A)   keep all types of intercellular chemicals from moving out of the neuron.
B)   keep all types of extracellular chemicals from moving into the neuron.
C)   control the exchange of chemicals between the inside and outside of the cell.
D)   produce chains of fatty acids and proteins.E) B) and C)
F) B) and D)

Question 6

When a neuron's membrane is at rest, the concentration gradient tends to move potassium ____ the cell and the electrical gradient tends to move it ____ the cell.

Accepted Answer

A)   into, into
B)   into, out of
C)   out of, into
D)   out of, out ofE) B) and C)
F) A) and D)

Question 7

After the peak of an action potential, what prevents sodium ions from continuing to enter the cell?

Accepted Answer

A)   There is no longer a concentration gradient for sodium.
B)   The sodium-potassium pump greatly increases its rate of activity.
C)   All the available sodium ions have already entered the cell.
D)   The sodium gates in the membrane close.E) C) and D)
F) A) and D)

Question 8

What is saltatory conduction?

Accepted Answer

The jumping of actio...

Question 9

What are the two kinds of cells in the nervous system?

Accepted Answer

A)   neurons and glia
B)   dendrites and axons
C)   ribosomes and lysosomes
D)   neurons and axonsE) B) and C)
F) A) and C)

Question 10

An afferent axon brings information into a structure.

Accepted Answer

A) True 
 B)False

Question 11

When a membrane is at rest, what attracts potassium ions to the inside of the cell?

Accepted Answer

A)   an electrical gradient
B)   a concentration gradient
C)   both an electrical gradient and a concentration gradient
D)   neither an electrical gradient nor a concentration gradientE) None of the above
F) B) and C)

Question 12

Compared to dendrites, axons usually:

Accepted Answer

A)   form the information-receiving pole of the neuron.
B)   are shorter than the dendrites.
C)   are covered with myelin.
D)   taper in diameter toward their periphery.E) A) and D)
F) B) and C)

Question 13

Which of the following is NOT true of axons?

Accepted Answer

A)   They can vary greatly in length.
B)   They carry information toward the soma.
C)   They release chemicals that cross the synapse.
D)   Some of them are covered with myelin sheaths.E) C) and D)
F) A) and B)

Question 14

The tree-like branches of a neuron that receive information from other neurons are called:

Accepted Answer

A)   axons.
B)   dendrites.
C)   soma.
D)   myelin.E) A) and B)
F) C) and D)

Question 15

What happens to the ion gates when the membrane of a neuron starts to be depolarized?

Accepted Answer

A)   Potassium gates close.
B)   Chloride gates open.
C)   Sodium gates close.
D)   Sodium gates open.E) A) and B)
F) B) and C)

Question 16

An axon has many branches, each of which swells at its tip. These are known as:

Accepted Answer

A)   presynaptic terminals.
B)   efferent axons.
C)   afferent axons.
D)   intrinsic neurons.E) A) and B)
F) C) and D)

Question 17

Neurons can have any number of dendrites, but no more than one axon.

Accepted Answer

A) True 
 B)False

Question 18

Saltatory conduction ____ the velocity of action potentials and ____ the amount of energy used by the neuron.

Accepted Answer

A)   decreases; decreases
B)   decreases; increases
C)   increases; decreases
D)   increases; increasesE) B) and D)
F) A) and C)

Question 19

The blood-brain barrier is made up of closely packed glial cells.

Accepted Answer

A) True 
 B)False

Question 20

Korsakoff's syndrome:

Accepted Answer

A)   is marked by severe memory impairments.
B)   results from too much thiamine.
C)   results from lack of oxygen to the brain.
D)   is due to a breakdown of the blood-brain barrier.E) All of the above
F) A) and B)

Exam 2: Nerve Cells and Nerve Impulses

Saltatory conduction ____ the velocity of action potentials and ____ the amount of energy used by the neuron.

Correct AnswerverifiedShow Answer

The blood-brain barrier is made up of closely packed glial cells.

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The membrane of a neuron is specialized to:

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What is saltatory conduction?

Correct AnswerverifiedThe jumping of actio...View AnswerShow Answer

The tree-like branches of a neuron that receive information from other neurons are called:

Correct AnswerverifiedShow Answer

An axon has many branches, each of which swells at its tip. These are known as:

Correct AnswerverifiedShow Answer

An afferent axon brings information into a structure.

Correct AnswerverifiedShow Answer

A neuron can have any number of ____, but no more than one ____.

Correct AnswerverifiedShow Answer

In what way is a myelinated axon that has lost its myelin (through disease) different from an axon that was never myelinated?

Correct AnswerverifiedShow Answer

Korsakoff's syndrome:

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Compared to dendrites, axons usually:

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When a neuron's membrane is at rest, the concentration gradient tends to move potassium ____ the cell and the electrical gradient tends to move it ____ the cell.

Correct AnswerverifiedShow Answer

After the peak of an action potential, what prevents sodium ions from continuing to enter the cell?

Correct AnswerverifiedShow Answer

What happens to the ion gates when the membrane of a neuron starts to be depolarized?

Correct AnswerverifiedShow Answer

Which of the following is NOT true of axons?

Correct AnswerverifiedShow Answer

When a membrane is at rest, what attracts potassium ions to the inside of the cell?

Correct AnswerverifiedShow Answer

The action potential of a neuron depends mostly on what movement of ions?

Correct AnswerverifiedShow Answer

If all of a neuron's dendrites or axons were contained within the spinal cord, it would be considered a(n) ____ neuron.

Correct AnswerverifiedShow Answer

What are the two kinds of cells in the nervous system?

Correct AnswerverifiedShow Answer

Neurons can have any number of dendrites, but no more than one axon.

Correct AnswerverifiedShow Answer

Saltatory conduction the velocity of action potentials and the amount of energy used by the neuron.

Correct Answer
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The jumping of actio...
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A neuron can have any number of , but no more than one .

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When a neuron's membrane is at rest, the concentration gradient tends to move potassium the cell and the electrical gradient tends to move it the cell.

Correct Answer
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