Resting Potential

Definition

The resting potential is the difference in electrical charge between the inside and outside of a cell when the cell is not actively transmitting an electrical signal. This potential difference is crucial for the functioning of neurons and other excitable cells within the nervous system.

5 Must Know Facts For Your Next Test

1. The resting potential is typically around -70 millivolts (mV), with the inside of the cell being negatively charged compared to the outside.
2. The resting potential is maintained by the unequal distribution of sodium and potassium ions across the cell membrane, which is regulated by the sodium-potassium pump.
3. Potassium ions (K+) are the main contributors to the resting potential, as they are able to freely move in and out of the cell through potassium channels.
4. The resting potential is essential for the generation of action potentials, which are the electrical signals that allow neurons to communicate with each other.
5. Disruptions to the resting potential, such as changes in ion concentrations or membrane permeability, can lead to neurological disorders and other health problems.

Review Questions

• Explain the role of the sodium-potassium pump in maintaining the resting potential.
  • The sodium-potassium pump is a crucial mechanism for maintaining the resting potential. It actively transports sodium ions (Na+) out of the cell and potassium ions (K+) into the cell, creating an electrochemical gradient. This unequal distribution of ions across the cell membrane results in the negatively charged interior of the cell compared to the outside, which is the resting potential. The continuous work of the sodium-potassium pump helps to sustain this potential difference, which is essential for the generation of action potentials and the proper functioning of neurons and other excitable cells.
• Describe how changes in membrane permeability can affect the resting potential.
  • The resting potential is directly influenced by the permeability of the cell membrane to different ions, particularly potassium (K+) and sodium (Na+). When the membrane is more permeable to potassium ions, the resting potential becomes more negative, as potassium ions can more easily move out of the cell. Conversely, if the membrane becomes more permeable to sodium ions, the resting potential becomes less negative, as sodium ions can more easily move into the cell. These changes in membrane permeability can be caused by various factors, such as the opening or closing of ion channels, and can lead to the generation of action potentials or disrupt the normal functioning of the cell.
• Analyze the importance of the resting potential in the context of the nervous system and its overall functioning.
  • The resting potential is a fundamental concept in the functioning of the nervous system. It is essential for the generation of action potentials, which are the electrical signals that allow neurons to communicate with each other and transmit information throughout the body. The resting potential provides the necessary baseline for the initiation of action potentials, which are triggered by the depolarization of the cell membrane. Without a stable resting potential, the ability of neurons to generate and propagate action potentials would be severely impaired, leading to disruptions in the neural communication and the overall functioning of the nervous system. The maintenance of the resting potential, through mechanisms like the sodium-potassium pump and the regulation of membrane permeability, is therefore crucial for the proper functioning of the nervous system and the body as a whole.

Related terms

Action Potential:

An action potential is a brief, rapid change in the electrical charge across the cell membrane of a neuron or other excitable cell, which travels along the cell and triggers the release of neurotransmitters at synapses.

Sodium-Potassium Pump: The sodium-potassium pump is an active transport mechanism that maintains the resting potential by actively pumping sodium ions out of the cell and potassium ions into the cell, creating an electrochemical gradient.

Membrane Permeability: Membrane permeability refers to the ease with which substances can move across the cell membrane, which is a key factor in maintaining the resting potential and generating action potentials.