Logothetis: Local Anesthesia for the
Dental Hygienist Chapter 02:
Neurophysiology Answers to End-of-
chapter Review Questions and Answers
Already Passed
What is the role of sodium ions during nerve impulse conduction?
A. They block the nerve impulse
B. They maintain the resting potential
✔✔ C. They rush into the neuron to depolarize it
D. They exit the cell during depolarization
What happens when a local anesthetic is applied to a nerve?
A. It opens sodium channels permanently
B. It stimulates the nerve
✔✔ C. It blocks sodium ion influx
D. It speeds up the nerve conduction
Which of the following best describes a resting nerve fiber?
1
,A. It is depolarized
B. It is flooded with sodium ions inside
✔✔ C. It has a negative charge inside
D. It has an action potential
What is the threshold potential in a neuron?
A. The most negative potential possible
✔✔ B. The minimum level required to trigger an action potential
C. The charge required to open potassium channels
D. The potential after repolarization
Which ion is primarily responsible for repolarization of the nerve?
✔✔ A. Potassium
B. Sodium
C. Calcium
D. Chloride
Which of the following statements is true about local anesthetics and nerve conduction?
2
,A. They stimulate potassium release
✔✔ B. They prevent depolarization by blocking sodium entry
C. They permanently alter nerve structure
D. They open calcium channels
Myelinated nerves conduct impulses more rapidly because:
A. They are shorter in length
B. They contain more sodium
✔✔ C. They use saltatory conduction between nodes
D. They require less energy
The all-or-none principle means:
✔✔ A. A nerve fires completely or not at all
B. A nerve only fires if a stimulus is weak
C. A stronger stimulus causes a larger action potential
D. The nerve will fire repeatedly with a weak signal
Where do local anesthetics primarily act on the neuron?
3
, A. The axon hillock
B. The synaptic vesicle
✔✔ C. The nerve membrane (axon membrane)
D. The dendrite
Which of the following is NOT needed for a nerve impulse to occur?
A. Sodium influx
✔✔ B. Permanent membrane blockage
C. Threshold stimulus
D. Membrane depolarization
Which statement about action potentials is correct?
A. They vary in strength depending on the stimulus
✔✔ B. They have the same size once threshold is reached
C. They increase with repeated stimuli
D. They occur without ion movement
What effect does local anesthesia have on nerve repolarization?
4
Dental Hygienist Chapter 02:
Neurophysiology Answers to End-of-
chapter Review Questions and Answers
Already Passed
What is the role of sodium ions during nerve impulse conduction?
A. They block the nerve impulse
B. They maintain the resting potential
✔✔ C. They rush into the neuron to depolarize it
D. They exit the cell during depolarization
What happens when a local anesthetic is applied to a nerve?
A. It opens sodium channels permanently
B. It stimulates the nerve
✔✔ C. It blocks sodium ion influx
D. It speeds up the nerve conduction
Which of the following best describes a resting nerve fiber?
1
,A. It is depolarized
B. It is flooded with sodium ions inside
✔✔ C. It has a negative charge inside
D. It has an action potential
What is the threshold potential in a neuron?
A. The most negative potential possible
✔✔ B. The minimum level required to trigger an action potential
C. The charge required to open potassium channels
D. The potential after repolarization
Which ion is primarily responsible for repolarization of the nerve?
✔✔ A. Potassium
B. Sodium
C. Calcium
D. Chloride
Which of the following statements is true about local anesthetics and nerve conduction?
2
,A. They stimulate potassium release
✔✔ B. They prevent depolarization by blocking sodium entry
C. They permanently alter nerve structure
D. They open calcium channels
Myelinated nerves conduct impulses more rapidly because:
A. They are shorter in length
B. They contain more sodium
✔✔ C. They use saltatory conduction between nodes
D. They require less energy
The all-or-none principle means:
✔✔ A. A nerve fires completely or not at all
B. A nerve only fires if a stimulus is weak
C. A stronger stimulus causes a larger action potential
D. The nerve will fire repeatedly with a weak signal
Where do local anesthetics primarily act on the neuron?
3
, A. The axon hillock
B. The synaptic vesicle
✔✔ C. The nerve membrane (axon membrane)
D. The dendrite
Which of the following is NOT needed for a nerve impulse to occur?
A. Sodium influx
✔✔ B. Permanent membrane blockage
C. Threshold stimulus
D. Membrane depolarization
Which statement about action potentials is correct?
A. They vary in strength depending on the stimulus
✔✔ B. They have the same size once threshold is reached
C. They increase with repeated stimuli
D. They occur without ion movement
What effect does local anesthesia have on nerve repolarization?
4
