When an Action Potential Reaches an Axon Terminal, Calcium

question 60

Multiple Choice

 When an action potential reaches an axon terminal, calcium

• A) rushes into the cell immediately, because this negatively charged ion is attracted to the now-positive environment of the axon terminal
• B) rushes out of the axon terminal, because this positively charged ion is repelled by the now-positive environment of the axon terminal.
• C) leaves the axon terminal as the action potential recedes, because that is when the calcium channels begin to open.
• D) enters the axon terminal as the action potential recedes, primarily due to diffusion.