Question 1

Stimulation of a neuron beyond a certain level is called the:

Accepted Answer

A)   firing threshold
B)   hillock threshold
C)   threshold of excitation
D)   threshold of inhibitionE) A) and B)
F) B) and C)

Question 2

Myelin covers:

Accepted Answer

A)   all axons
B)   most dendrites
C)   some axons in vertebrates and none in invertebrates
D)   all vertebrate axons and some invertebrate axonsE) C) and D)
F) B) and C)

Question 3

Dendrites contain the nuclei, ribosomes, mitochondria, and other structures found in most cells.

Accepted Answer

A) True 
 B)False

Question 4

Which of the following is an advantage of having a resting potential?

Accepted Answer

A)   The toxic effects of sodium are minimized inside the cell.
B)   No energy is required to maintain it.
C)   The cell is prepared to respond quickly to a stimulus.
D)   All of the ions are maintained in equal concentrations throughout the cytoplasm.E) B) and C)
F) B) and D)

Question 5

One disadvantage of the blood-brain barrier is that it keeps out most forms of nutrition.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following would produce a hyperpolarization of a neuron?

Accepted Answer

A)   applying a negative charge inside the neuron with a microelectrode
B)   applying a positive charge inside the neuron with a microelectrode
C)   increasing the membrane's permeability to sodium
D)   decreasing the membrane's permeability to potassiumE) All of the above
F) B) and C)

Question 7

Which two factors affect the speed of an action potential?

Accepted Answer

A)   the strength and frequency of the stimulus
B)   the location of the cell body and the length of the axon
C)   the length and diameter of the axon
D)   the presence of myelin and the diameter of the axonE) All of the above
F) A) and B)

Question 8

Who was the first researcher to demonstrate that neurons are separate from one another?

Accepted Answer

A)   Curt P. Richter
B)   Santiago Ramon y Cajal
C)   Charles S. Sherrington
D)   Jose DelgadoE) C) and D)
F) A) and B)

Question 9

When the neuron is at rest, what is responsible for moving potassium ions OUT of the cell?

Accepted Answer

A)   a concentration gradient
B)   an electrical gradient
C)   both a concentration gradient and an electrical gradient
D)   the sodium-potassium pumpE) None of the above
F) All of the above

Question 10

Which of the following is an important function of the blood-brain barrier?

Accepted Answer

A)   It enables more nutrients to reach the brain.
B)   It maintains an electrical gradient.
C)   It aids in the production of neurotransmitters.
D)   It protects the brain from most viruses.E) C) and D)
F) A) and B)

Question 11

If the brain does not have enough thiamine, what is it unable to do?

Accepted Answer

A)   maintain its blood-brain barrier
B)   pump glucose across the blood-brain barrier
C)   produce certain neurotransmitters
D)   metabolize glucoseE) A) and B)
F) A) and D)

Question 12

Suppose we applied a drug to a neuron that caused its sodium gates to suddenly open wide. What would happen?

Accepted Answer

A)   hyperpolarization of the membrane
B)   an increase in the threshold
C)   an action potential
D)   nothing, because potassium gates would compensateE) B) and D)
F) A) and C)

Question 13

What is one major cause for the resting potential of a neuron's membrane?

Accepted Answer

A)   a difference in size between axons and dendrites
B)   a high permeability of the membrane to water molecules
C)   the refractory period of the membrane
D)   the sodium-potassium pumpE) A) and B)
F) A) and C)

Question 14

Protein channels allow ____ to cross the cell membrane.

Accepted Answer

A)   large charged molecules
B)   small charged molecules
C)   large uncharged molecules
D)   small uncharged moleculesE) C) and D)
F) B) and D)

Question 15

When the neuron is at rest, what is responsible for moving potassium ions into the cell?

Accepted Answer

A)   concentration gradient
B)   an electrical gradient
C)   the sodium-potassium pump
D)   both the sodium-potassium pump and electrical gradientE) A) and B)
F) B) and C)

Question 16

A greater amount of branching on dendrites allows them to:

Accepted Answer

A)   manufacture more mitochondria.
B)   have a larger surface area available for receiving information from other neurons.
C)   increase their membrane permeability.
D)   lower their resting potential.E) C) and D)
F) All of the above

Question 17

What is the difference in voltage called that typically exists between the inside and the outside of a neuron?

Accepted Answer

A)   concentration gradient
B)   generator potential
C)   resting potential
D)   shock valueE) A) and B)
F) A) and C)

Question 18

When the neuronal membrane is at rest, the sodium channels:

Accepted Answer

A)   permit sodium ions to pass quickly and easily.
B)   permit potassium ions to cross instead of sodium.
C)   are closed.
D)   fluctuate rapidly between open and closed.E) A) and B)
F) None of the above

Question 19

Which of the following is NOT true of astrocytes?

Accepted Answer

A)   They wrap around the presynaptic terminals of several axons.
B)   They help synchronize the activity of the axons.
C)   They remove waste material.
D)   They make up the myelin sheaths in the periphery of the body.E) A) and B)
F) B) and C)

Question 20

Axons are covered with an insulating material called a myelin sheath.

Accepted Answer

A) True 
 B)False

Exam 2: Nerve Cells and Nerve Impulses

Suppose we applied a drug to a neuron that caused its sodium gates to suddenly open wide. What would happen?

Correct AnswerverifiedShow Answer

One disadvantage of the blood-brain barrier is that it keeps out most forms of nutrition.

Correct AnswerverifiedShow Answer

What is the difference in voltage called that typically exists between the inside and the outside of a neuron?

Correct AnswerverifiedShow Answer

Axons are covered with an insulating material called a myelin sheath.

Correct AnswerverifiedShow Answer

Protein channels allow ____ to cross the cell membrane.

Correct AnswerverifiedShow Answer

When the neuron is at rest, what is responsible for moving potassium ions OUT of the cell?

Correct AnswerverifiedShow Answer

Who was the first researcher to demonstrate that neurons are separate from one another?

Correct AnswerverifiedShow Answer

Dendrites contain the nuclei, ribosomes, mitochondria, and other structures found in most cells.

Correct AnswerverifiedShow Answer

When the neuron is at rest, what is responsible for moving potassium ions into the cell?

Correct AnswerverifiedShow Answer

If the brain does not have enough thiamine, what is it unable to do?

Correct AnswerverifiedShow Answer

Myelin covers:

Correct AnswerverifiedShow Answer

A greater amount of branching on dendrites allows them to:

Correct AnswerverifiedShow Answer

Which of the following would produce a hyperpolarization of a neuron?

Correct AnswerverifiedShow Answer

When the neuronal membrane is at rest, the sodium channels:

Correct AnswerverifiedShow Answer

Which of the following is an important function of the blood-brain barrier?

Correct AnswerverifiedShow Answer

Stimulation of a neuron beyond a certain level is called the:

Correct AnswerverifiedShow Answer

What is one major cause for the resting potential of a neuron's membrane?

Correct AnswerverifiedShow Answer

Which two factors affect the speed of an action potential?

Correct AnswerverifiedShow Answer

Which of the following is NOT true of astrocytes?

Correct AnswerverifiedShow Answer

Which of the following is an advantage of having a resting potential?

Correct AnswerverifiedShow Answer

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