Lepopotentiaaliaan

Lepopotentiaaliaan is a Finnish term that translates to "resting potential" in English. It refers to the electrical potential difference across the plasma membrane of a neuron or muscle cell when it is not actively transmitting a signal. This state is characterized by a difference in the concentration of ions inside and outside the cell, primarily sodium (Na+) and potassium (K+).

In a typical resting neuron, the inside of the cell has a higher concentration of potassium ions and negatively charged proteins, while the outside of the cell has a higher concentration of sodium ions and chloride ions. This uneven distribution of ions is maintained by ion pumps, such as the sodium-potassium pump, which actively transports ions against their concentration gradients.

The resting potential is typically negative, with values ranging from -60 to -80 millivolts. This negativity is largely due to the selective permeability of the cell membrane to potassium ions, which leak out of the cell down their concentration gradient, and the presence of negatively charged molecules trapped within the cell. The resting potential is crucial for cellular function as it allows the cell to be excitable, meaning it can respond to stimuli by generating electrical signals like action potentials.