Na+ channels are specialized proteins found in the cell membranes of neurons and muscle cells. They play a crucial role in generating and propagating electrical signals by allowing sodium ions (Na+) to flow into the cell when the membrane is depolarized. This influx of sodium ions leads to a rapid change in the cell's electrical charge, which is essential for processes like muscle contraction and nerve impulse transmission. These channels open in response to specific stimuli, such as changes in voltage across the membrane. Once activated, they quickly allow Na+ ions to enter the cell, contributing to the rising phase of an action potential. After a brief period, the channels close, and the cell returns to its resting state, ready for the next signal.