Final Exam

Question 1

The electrical potential of the neuron is approximately -70 mV.

Answer 1

Polarization

Question 2

During this stage, the electrical charge on the outside of the membrane is positive, while the electrical charge on the inside of the membrane is negative.

Answer 2

Polarization

Question 3

The outside of the cell contains excess sodium ions at a ratio of 14:1; the inside of the cell contains excess potassium ions.

Answer 3

Polarization

Question 4

The resting potential of the cell changes to become more negative, but not enough to trigger the firing threshold.

Answer 4

Slow depolarization

Question 5

The nerve is stimulated by the minimal threshold level.

Answer 5

Rapid depolarization

Question 6

The gated Na+ channels on the resting neuron’s membrane release and open suddenly in order to allow the Na+ in the extracellular fluid to influx into the cell.

Answer 6

Rapid depolarization

Question 7

The impulse moves between the uninsulated nodes of Ranvier that exist between each Schwann cell.

Answer 7

Rapid depolarization

Question 8

Occurs once the peak of the action potential is reached and the membrane potential begins to move back toward the resting potential.

Answer 8

Repolarization

Question 9

During this stage, the second action potential is inhibited but not impossible should a larger stimulus be applied.

Answer 9

Relative refractory period

Question 10

The interval during which a second action potential cannot be initiated, no matter how large a stimulus is applied.

Answer 10

Absolute refractory period

Question 11

The lipoprotein sheath that surrounds many neurons is called ______ and is composed of ______.

A. Lipid; oligodendrocytes
B. Myelin sheath; Schwann cells
C. Nodes of Ranvier; Schwann cells
D. White fibers; oligodendrocytes

Answer 11

B. Myelin sheath; Schwann cells

Question 12

Which description best describes the mechanism by which local anesthetic drugs work?

A. Anesthetic drugs bind to the sodium channels, the influx of sodium is interrupted,
the action potential cannot rise, and the signal conduction is inhibited.
B. Anesthetic drugs bind to the potassium channels, the influx of sodium is
interrupted, the action potential cannot rise, and the signal conduction is inhibited.
C. Anesthetic drugs bind to the sodium channels, the influx of potassium is
interrupted, the action potential cannot rise, and the signal conduction is inhibited.

Answer 12

A. Anesthetic drugs bind to the sodium channels, the influx of sodium is interrupted,
the action potential cannot rise, and the signal conduction is inhibited.

Question 13

Which description best describes the mechanism by which local anesthetic drugs work?

A. Anesthetic drugs bind to the sodium channels, the influx of sodium is interrupted,
the action potential cannot rise, and the signal conduction is inhibited.
B. Anesthetic drugs bind to the potassium channels, the influx of sodium is
interrupted, the action potential cannot rise, and the signal conduction is inhibited.
C. Anesthetic drugs bind to the sodium channels, the influx of potassium is
interrupted, the action potential cannot rise, and the signal conduction is inhibited.
D. Anesthetic drugs bind to the sodium channels, the influx of sodium and potassium
is interrupted, the action potential cannot rise, and the signal conduction is inhibited.
A. Anesthetic drugs bind to the sodium channels, the influx of sodium is interrupted,
the action potential cannot rise, and the signal conduction is inhibited.
The nerve cell stage in which potassium returns to the inside of the cell and sodium returns to the outside of the cell is called what?

A. All-or-none principle
B. Polarization
C. Depolarization
D. Refractory period

Answer 13

D. Refractory period

Question 14

Why is protein binding an important characteristic of local anesthetic drugs?

A. Increased protein binding allows more cations (RNH+) to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.
B. Increased protein binding allows more RN molecules to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.
C. Decreased protein binding allows more cations (RNH+) to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.
D. Decreased protein binding allows more RN molecules to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of action.

Answer 14

A. Increased protein binding allows more cations (RNH+) to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.

Question 15

Why is protein binding an important characteristic of local anesthetic drugs?

A. Increased protein binding allows more cations (RNH+) to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.
B. Increased protein binding allows more RN molecules to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.
C. Decreased protein binding allows more cations (RNH+) to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.
D. Decreased protein binding allows more RN molecules to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of action.
A. Increased protein binding allows more cations (RNH+) to bind to the receptor sites
within the sodium channels, prolonging the presence of anesthetic at the site of
action.
What does the membrane expansion theory of the action of local anesthetics suggest?

A. Anesthetics that are highly hydrophilic cause the matrix of the nerve membrane to
expand, narrowing the sodium channels, thus preventing depolarization.
B. Anesthetics that are highly lipid soluble cause the lipoprotein matrix of the nerve
membrane to expand, narrowing the sodium channels, thus preventing
depolarization.
C. Anesthetics cause the sodium channels to expand, thus allowing the increase in
protein binding within the channels.
D. All of the above

Answer 15

B. Anesthetics that are highly lipid soluble cause the lipoprotein matrix of the nerve
membrane to expand, narrowing the sodium channels, thus preventing
depolarization.

Question 16

The importance of aspirating prior to anesthetic deposition and the potential hazards associated with intravascular injections are widely known and accepted. The self-aspirating syringe achieves the positive pressure for an aspiration without a harpoon.

A. Both statements are true.
B. Both statements are false.
C. The first statement is true; the second statement is false.
D. The first statement is false; the second statement is true.

Answer 16

C. The first statement is true; the second statement is false.

Question 17

1. Which area of the maxilla articulates with the other to form the anterior or major part of the hard palate?

A. Zygomatic process
B. Frontal process
C. Palatine process
D. Alveolar processes

Answer 17

C. Palatine process

Question 18

What does the MRD depend on?

A. The patient’s weight
B. The patient’s health
C. Whether the anesthetic contains a vasoconstrictor or not
D. All of the above

Answer 18

A. The patient’s weight

Question 19

Which of the following is the first step in calculating the additional dose of a different drug?

A. Calculate how many milligrams of drug #1 have already been administered.
B. Calculate MRD of drug #2.
C. Review patient’s history to determine appropriateness of new drug.
D. Consult with dentist and/or physician.

Answer 19

C. Review patient’s history to determine appropriateness of new drug.

Question 20

What is the name of the local anesthetic that does not follow the above rule and is packaged in a different quantity of solution per individual cartridge?

A. Lidocaine
B. Articaine
C. Mepivacaine
D. Butacaine

Answer 20

B. Articaine

Question 21

What is the MRD of mepivacaine for a 130-lb female patient?

A. 260 mg of mepivacaine
B. 275 mg of mepivacaine
C. 300 mg of mepivacaine
D. 572 mg of mepivacaine

Answer 21

A. 260 mg of mepivacaine

Question 22

If a patient’s MRD is 240 mg and 108 mg of 3% mepivacaine has already been administered, how much more mepivacaine can the patient receive?

A. 0 mg of 3% mepivacaine; a different local anesthetic should be selected
B. 30 mg of 3% mepivacaine
C. 348 mg of 3% mepivacaine
D. 132 mg of 3% mepivacaine

Answer 22

D. 132 mg of 3% mepivacaine

Question 23

Which anesthetic/vasoconstrictor combination is most likely to limit the anesthetic drug?

A. Lidocaine 2% 1:50,000 epinephrine
B. Lidocaine 2% 1:100,000 epinephrine
C. Mepivacaine 3% 1:20,000 levonordefrin
D. All of the above

Answer 23

A. Lidocaine 2% 1:50,000 epinephrine

Question 24

What is the lipid solubility and the protein-binding ability of the local anesthetic related to?

A. Anesthetic dissociation constant
B. Anesthetic duration of action
C. Distribution of cations and anions
D. All of the above

Answer 24

B. Anesthetic duration of action

Question 25

Which amide anesthetic agent is metabolized in both the plasma and the liver?

A. Lidocaine
B. Mepivacaine
C. Prilocaine
D. Articaine

Answer 25

D. Articaine