Neurons Resting Membrane Potential

Key Concepts

• Neurons exist in an electrically imbalanced state.
• This imbalance is due to the number of positive and negative ions inside and outside the cell.

Neuron Cell Membrane

• Inside Neuron:
  • Contains a number of negatively charged ions.
  • Types of negative ions:
    • Organic acids (e.g., carboxylic acid)
    • Phosphates
    • Sulfates
    • Proteins
    • RNA
    • ATP
  • These ions make the inside of the cell more negative compared to outside.

Ion Movement

• Potassium Channels:
  • Allow potassium (K⁺) to move from inside to outside the cell.
  • Loss of positive potassium ions makes the inside of the cell more negative.
• Sodium Channels:
  • Allow sodium (Na⁺) to move into the cell.
  • The cell membrane is more permeable to potassium than sodium, leading to a net loss of positive charge.

Sodium-Potassium Pump

• An active transport protein that uses ATP for energy.
• Pumps 3 sodium ions out and 2 potassium ions into the cell.
• Maintains the sodium and potassium gradients by moving ions against their gradients.

Resting Membrane Potential

• The result of these processes is the neuron's resting membrane potential.
• Value: Approximately -70 millivolts.

Conclusion

• Understanding resting membrane potential is crucial to grasping how neurons function in transmitting signals.