Ch. 3 - Evolve Quiz Questions Flashcards
Local anesthetics work by preventing the nerve from reaching a state of polarization. The conduction of the nerve impulse is prevented as long as the anesthetic is bound to the receptor sites.
a) The 1st statement is TRUE; the 2nd statement is FALSE.
b) The 1st statement is FALSE; the 2nd statement is TRUE.
c) Both statements are TRUE.
d) Both statements are FALSE.
B) THE 1st STATEMENT IS FALSE; THE 2nd STATEMENT IS TRUE.
[Local anesthetics block the conduction of a nerve impulse by PREVENTING DEPOLARIZATION.]
All injectable local anesthetics used in dental offices today belong to the _____ group.
a) amide
b) ester
c) Both a & b
d) Neither a nor b
A) AMIDE
[A high degree of allergic hypersensitivity makes the ester group undesirable as an injectable local anesthetic.]
The _____ lipid soluble an anesthetic is, the _____ its potency.
a) more, less
b) less, greater
c) less, lesser
d) more, greater
D) MORE, GREATER
[The more lipid soluble the base form of its molecule is, the more potent a drug is. The potency & the lipid solubility of a local anesthetic are positively correlated: the more lipid soluble an anesthetic is, the greater its potency.]
Which of the following is TRUE regarding topical anesthetic agents?
a) Topical anesthetics do not pose a risk of toxicity, even when applied in large amounts.
b) The application of a topical anesthetic is more effective than a submucosal injection.
c) Topical anesthetics are highly concentrated.
d) Topical anesthetics are applied below the surface of the mucous membrane.
C) TOPICAL ANESTHETICS ARE HIGHLY CONCENTRATED.
[Topical anesthesia is designed to be absorbed through the oral mucous membrane. The concentration of topical anesthetic agents must be high to facilitate the diffusion of the drug. Topical anesthetics DO pose a risk of toxicity if large amounts are applied in a limited region. Submucosal injections are MORE EFFECTIVE than topical anesthetics, and they are applied below the surface of the mucous membrane. Topical anesthetics are applied to THE SURFACE of the mucous membrane.]
Prior to injection, _____ local anesthetic solutions are _____.
a) All, acidic
b) No, acidic
c) All, basic
d) 80% of, acidic
A) ALL, ACIDIC
[No local anesthetic solutions are basic prior to injection. 100% of ALL local anesthetic agents are ACIDIC before they are injected.]
The oral tissues of a patient with an inflamed dental infection will will be more acidic. A lower tissue pH makes effective dental anesthesia more difficult.
a) The 1st statement is TRUE; the 2nd statement is FALSE.
b) The 1st statement is FALSE; the 2nd statement is TRUE.
c) Both statements are TRUE.
d) Both statements are FALSE.
C) BOTH STATEMENTS ARE TRUE.
[Tissues with a lower pH (high acidity) make profound anesthesia difficult.]
The mantle bundles innervate the anterior teeth at the end of the nerve fiber. The further anterior a tooth is located along a nerve fiber, the less likely it is to experience profound anesthesia.
a) The 1st statement is TRUE; the 2nd statement is FALSE.
b) The 1st statement is FALSE; the 2nd statement is TRUE.
c) Both statements are TRUE.
d) Both statements are FALSE.
B) THE 1st STATEMENT IS FALSE; THE 2nd STATEMENT IS TRUE.
[The mantle fibers innervate the POSTERIOR teeth (molars); the core fibers innervate the anterior teeth.]
Which of the following statements is generally TRUE?
a) induction time recovery time
d) recovery time = induction time
A) INDUCTION TIME
Which of the following best describes TACHYPHYLAXIS?
a) An equation used to calculate the pH of a buffer solution.
b) The decreased potency of an anesthetic in acidic tissues.
c) The study of the action of drugs within the body
d) A term used to describe an increased tolerance to a drug.
D) A TERM USED TO DESCRIBE AN INCREASED TOLERANCE TO A DRUG
[Tachyphylaxis is the term used to describe an increased tolerance to a drug that is repeatedly administered, and it is NOT defined as the decreased potency of an anesthetic in acidic tissues. Pharmacokinetics is the study of the action of drugs within the body. Henderson-Hasselbach equation is an equation used to calculate the pH of a buffer solution.]
Which of the following will decrease the duration of a local anesthetic?
a) A firm binding to the receptor site
b) Increased vascularity
c) Presence of a vasoconstrictor in the anesthetic
d) All of the above
B) INCREASED VASCULARITY
[The duration of a local anesthetic is decreased in areas of rapid systemic absorption. Longer-acting anesthetics bind more firmly to the receptor site, which will increase the duration of a local anesthetic. An added vasoconstrictor will increase the anesthetics duration.]
Injecting anesthetic into a patient’s blood vessel _____ the risk of an overdose.
a) decreases
b) has no significant effect on
c) increases
d) eliminates
C) INCREASES
[Local anesthetic injected into the blood stream can easily cross the blood-brain barrier, significantly increasing the risk of overdose.]
Once absorbed into the blood stream, local anesthetic accumulates in the tissues of the body, including the heart, liver, kidneys, and lungs. Fortunately, local anesthetics cannot cross the blood-brain barrier.
a) The 1st statement is TRUE; the 2nd statement is FALSE.
b) The 1st statement is FALSE; the 2nd statement is TRUE.
c) Both statements are TRUE.
d) Both statements are FALSE.
A) THE 1st STATEMENT IS TRUE; THE 2nd STATEMENT IS FALSE.
[Local anesthetics EASILY cross the blood-brain barrier.]
Which of the following will influence a local anesthetic’s toxicity?
a) The anesthetic’s half-life
b) The patient’s emotional state
c) Other medications the patient may be taking
d) Both a & c
D) BOTH A & C
[The rate of absorption & elimination (half-life) & the interactions of other meds all influence the anesthetic’s degree of toxicity. The patient’s emotional state has NO influence on the toxicity of a local anesthetic.]
Which of the following is LEAST likely to cause an allergic reaction?
a) Procaine
b) Lidocaine
c) Tetracaine
d) Benzocaine
B) LIDOCAINE
[Lidocaine is the only choice that belongs to the amide group; it’s LESS PRONE to allergic responses, because it’s metabolized in the liver. Procaine is occasionally used in dentistry, but it belongs to the ester group & has a high potential for provoking an allergic reaction. Tetracaine & Benzocaine are used as topical anesthetics, belongs to the ester group, & has a high potential for provoking an allergic reaction.]
Which amide is metabolized in both the liver & the lungs?
a) Prilocaine
b) Procaine
c) Mepivacaine
d) Articaine
A) PRILOCAINE
[Metabolized in both the lungs & the liver, prilocaine is rapidly biotransformed. Procaine is primarily metabolized in the plasma by an enzyme. Mepivacaine is primarily metabolized in the liver. Articaine is primarily metabolized in the plasma by an enzyme, although 10% is biotransformed in the liver.]
