The electrical potential difference between the outside and inside of a nerve axon before excitation is known as the resting membrane potential. This is an essential characteristic of nerve cells that allows them to transmit electrical signals or impulses.

Resting Membrane Potential:

The resting membrane potential refers to the electrical charge difference that exists across the cell membrane of a neuron when it is at rest. This potential difference is created by the distribution of ions (charged particles) across the membrane and is crucial for the proper functioning of the neuron.

Key Factors Affecting Resting Membrane Potential:

1. Ion Channels: The cell membrane contains various ion channels that allow the movement of specific ions across the membrane. These channels include sodium (Na+), potassium (K+), and chloride (Cl-) channels.

2. Sodium-Potassium Pump: The sodium-potassium pump actively transports sodium ions out of the cell and potassium ions into the cell. This pump helps maintain the concentration gradients of these ions, which is essential for establishing the resting membrane potential.

3. Ionic Concentration Gradient: The concentration of ions, particularly sodium and potassium, is different inside and outside the cell. The intracellular concentration of potassium is higher, while the extracellular concentration of sodium is higher.

4. Selective Permeability: The cell membrane is selectively permeable, meaning that it allows the movement of certain ions while restricting others. This property is primarily due to the presence of ion channels.

Key Points:

- The resting membrane potential is the electrical potential difference between the inside and outside of a nerve axon before excitation.
- It is created by the distribution of ions across the cell membrane.
- Key factors affecting resting membrane potential include ion channels, the sodium-potassium pump, ionic concentration gradients, and selective permeability.
- The resting membrane potential is crucial for the proper functioning of neurons and enables the transmission of electrical signals.

Resting potential