Depolarisointumaan
Depolarisointumaan is a Finnish term that translates to "depolarization" in English, a concept fundamental to understanding electrical activity in biological systems, particularly in neurons and muscle cells. It describes the process by which the electrical potential difference across the cell membrane of a neuron or muscle cell becomes less negative. Normally, the inside of a cell is more negative than the outside, creating an electrical gradient. Depolarization occurs when positive ions, such as sodium (Na+) or calcium (Ca2+), flow into the cell, making the inside of the membrane less polarized, or closer to zero. This influx of positive charge reduces the membrane potential. If the depolarization reaches a certain threshold level, it triggers an action potential, which is a rapid and transient change in membrane potential that allows for the transmission of electrical signals. This process is crucial for nerve impulse conduction and muscle contraction. Conversely, repolarization is the return of the membrane potential to its resting, negative state.