Final answer:
The two most important ions in neural activity are potassium and sodium. Potassium helps establish the resting membrane potential, while sodium generates action potentials.
Step-by-step explanation:
The two most important ions in neural activity are potassium and sodium. Potassium helps establish the resting membrane potential in neurons and muscle fibers, while sodium is responsible for generating action potentials. These ions enter the cell through ion channels, which are special proteins in the cell membrane that allow ions to pass through. The flow of ions into and out of the neuron changes the relative charge inside the neuron compared to the outside, creating electrical signals.