CRDTS Exam UPDATED QUESTIONS
AND CORRECT ANSWERS
Repolarization of the nerve after stimulation is primarily caused by: - CORRECT
ANSWER Active transport of sodium (Na.) out of the cell
How does a nerve conduct an impulse? - CORRECT ANSWER By sequential neuron
cell membrane depolarization from segment to segment or node to node
The two stages of an action potential are: - CORRECT
ANSWER Depolarization/repolarization
Local anesthetic agents prevent depolarization by: - CORRECT ANSWER Preventing
transfer of Na. ions from the exterior of the nerve to the interior
Once the minimal threshold stimulus has been reached, the impulse will travel the entire
length of the fiber without stimulation. This explains: - CORRECT ANSWER All-or-
none law
The gauge of a dental needle MOST recommended for intraoral injections with high risk of
aspiration is: - CORRECT ANSWER 25 gauge
All of the statements concerning local anesthetic needles are true EXCEPT one. Which one is
the EXCEPTION?
The term gaugerefers to the diameter of the lumen of the needle
The weakest portion of the needle is at its hub
Larger needles provide more reliable aspirations
Disposable needles will not normally become dull for at least 10 insertions
Larger needles should be employed when a greater risk of positive aspiration exists -
CORRECT ANSWER Disposable needles will not normally become dull for at least 10
insertions
They dull after 3-4 insertions
, All of the statements concerning local anesthetic cartridges are true EXCEPT one. Which one
is the EXCEPTION?
The glass dental cartridge should not be autoclaved
No alcohol should be present around the cartridges when they are stored outside the
packaging container
The rubber plunger is treated with silicone to decrease the incidence of "sticky stoppers"
Cartridges exposed to extended periods of direct sunlight may have their contents undergo
accelerated destruction
Manufacturers recommend freezing cartridges so that they may be used beyond the posted
expiration date - CORRECT ANSWER Manufacturers recommend freezing cartridges
so that they may be used beyond the posted expiration date
Freezing will cause pain upon depositing
The purpose of aspirating before injecting a local anesthetic solution is to prevent: -
CORRECT ANSWER Intravascular injections
Why do local anesthetics NOT work well in infected tissues? - CORRECT
ANSWER The lower pH of infected tissue
Increased edema
Increased vascularity
Lidocaine is metabolized primarily in the: - CORRECT ANSWER Liver
Complete the sentence with the MOST accurate phrase. Local
anesthetics______________________. - CORRECT ANSWER Dissociate in the
tissues, liberating free base, which can diffuse through the nerve membrane
Tissues with higher pH will cause:
Rapid hydrolysis of the anesthetic solution:
Decreased disassociation of the anesthetic drug)
AND CORRECT ANSWERS
Repolarization of the nerve after stimulation is primarily caused by: - CORRECT
ANSWER Active transport of sodium (Na.) out of the cell
How does a nerve conduct an impulse? - CORRECT ANSWER By sequential neuron
cell membrane depolarization from segment to segment or node to node
The two stages of an action potential are: - CORRECT
ANSWER Depolarization/repolarization
Local anesthetic agents prevent depolarization by: - CORRECT ANSWER Preventing
transfer of Na. ions from the exterior of the nerve to the interior
Once the minimal threshold stimulus has been reached, the impulse will travel the entire
length of the fiber without stimulation. This explains: - CORRECT ANSWER All-or-
none law
The gauge of a dental needle MOST recommended for intraoral injections with high risk of
aspiration is: - CORRECT ANSWER 25 gauge
All of the statements concerning local anesthetic needles are true EXCEPT one. Which one is
the EXCEPTION?
The term gaugerefers to the diameter of the lumen of the needle
The weakest portion of the needle is at its hub
Larger needles provide more reliable aspirations
Disposable needles will not normally become dull for at least 10 insertions
Larger needles should be employed when a greater risk of positive aspiration exists -
CORRECT ANSWER Disposable needles will not normally become dull for at least 10
insertions
They dull after 3-4 insertions
, All of the statements concerning local anesthetic cartridges are true EXCEPT one. Which one
is the EXCEPTION?
The glass dental cartridge should not be autoclaved
No alcohol should be present around the cartridges when they are stored outside the
packaging container
The rubber plunger is treated with silicone to decrease the incidence of "sticky stoppers"
Cartridges exposed to extended periods of direct sunlight may have their contents undergo
accelerated destruction
Manufacturers recommend freezing cartridges so that they may be used beyond the posted
expiration date - CORRECT ANSWER Manufacturers recommend freezing cartridges
so that they may be used beyond the posted expiration date
Freezing will cause pain upon depositing
The purpose of aspirating before injecting a local anesthetic solution is to prevent: -
CORRECT ANSWER Intravascular injections
Why do local anesthetics NOT work well in infected tissues? - CORRECT
ANSWER The lower pH of infected tissue
Increased edema
Increased vascularity
Lidocaine is metabolized primarily in the: - CORRECT ANSWER Liver
Complete the sentence with the MOST accurate phrase. Local
anesthetics______________________. - CORRECT ANSWER Dissociate in the
tissues, liberating free base, which can diffuse through the nerve membrane
Tissues with higher pH will cause:
Rapid hydrolysis of the anesthetic solution:
Decreased disassociation of the anesthetic drug)
