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Local Anesthesia Chapter 5 Questions and Answers with Certified Solutions
What is the primary way local anesthetics prevent nerve impulse conduction?✔✔ By blocking sodium ion channels in the nerve membrane
What happens to a nerve impulse when local anesthesia is successful?✔✔ The impulse is stopped and does not reach the brain
Why is the resting membrane potential important in nerve conduction?✔✔ It maintains the balance needed for depolarization to occur
What is the usual resting membrane potential of a nerve cell?✔✔ Around –70 millivolts
What is depolarization in the context of nerve conduction?✔✔ A temporary reversal of the resting membrane potential
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What causes depolarization to begin in a normal nerve cell?✔✔ A stimulus allows sodium ions to enter the cell
What effect does local anesthetic have on depolarization?✔✔ It prevents sodium from entering, so depolarization cannot happen
Why must an anesthetic be in the unionized (base) form to be effective?✔✔ Only the base form can penetrate the nerve membrane
What happens to local anesthetic in an acidic environment?✔✔ More of it becomes ionized and less effective
Which part of the neuron is most affected by local anesthetics?✔✔ The axon at the nodes of Ranvier
How do local anesthetics differ from general anesthetics?✔✔ They block sensation in a specific area without affecting consciousness
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