Exam Questions and CORRECT Answers
Local anesthesia depresses excitation in nerve endings or inhibiting the conduction of what
nerves? - CORRECT ANSWER - periphreal
LA differe from other drugs in that most other drugs are absorbed in the blood stream but LA
stop their action once absorbed where? - CORRECT ANSWER - systemic circulation
Why are vasoconstrictors added to LA? - CORRECT ANSWER - decrease blood flow at
injection site, constrict blood vessels and allows for a longer working time more profound
anesthesia and less bleeding
Why are additives and preservatives added to LA? - CORRECT ANSWER - prolong the
shelf life by using antioxidant properties
What are two examples of additives and preservatives? - CORRECT ANSWER - sodium
bisulfite and sodium metasulfite
Asthma patients are sensitive to what additive? - CORRECT ANSWER - sulfites
If a person is allergic to sodium bisulfite do you use vasoconstrictor? - CORRECT
ANSWER - No
What does a yellow brown tint indicate? - CORRECT ANSWER - oxidation
What should you do if there is oxidation in the carpule? - CORRECT ANSWER - dispose
of it.
, Are LA's vasodilators or vasoconstrictors? - CORRECT ANSWER - vasodilators except
cocaine its a vasoconstrictor
What phase of nerve conduction has positive ca+ on the outside and negative on the inside with
no movement of ions? - CORRECT ANSWER - resting state
What phase of nerve conduction has increase permeability to NA+ ions becomes less negative
within the nerve? - CORRECT ANSWER - deolarization slow phase
What phase of nerve conduction has enough stimulous to make nerve fire with influx of sodium?
- CORRECT ANSWER - rapid depolarization
What phase of nerve conduction returns to resting state which Na goes out of the nerve and k
returns in the nerve. influx of K+ - CORRECT ANSWER - Repolarization
What is the site of action for a LA? - CORRECT ANSWER - nerve membrane
LA are alkaloid bases meaning they are? - CORRECT ANSWER - wea combine with
acids to form water soluble salts.
Base form is lipophilic and non ionized or hydrohillic and ionized? - CORRECT
ANSWER - lipophilic and non ionized.
ph of normal tissue is - CORRECT ANSWER - 7.3 to 7.4
ph of local anesthesia is - CORRECT ANSWER - 5.5
ph of local anesthesia with epinephrine is - CORRECT ANSWER - 3.3