Why does depolarization occur in a neuron during an action potential?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

A local potential is a change in membrane potential that conducts the long-distance signals of the nervous system.

A drug that blocks Na⁺ channels in neurons does so not only in the axon but also in the dendrites and cell body. What overall effect would this have on action potential generation?

What would happen if the drug blocked K⁺ channels instead?

Describe the steps involved in the generation of an action potential.