What mechanism maintains the resting potential of a neuron?

What mechanism maintains the resting potential of a neuron?

• A. Calcium pump
• B. Sodium-potassium pump
• C. Chloride channel
• D. Potassium leak channel

Answer: (B)

The sodium-potassium pump is instrumental in maintaining the resting membrane potential of neurons. This pump actively transports sodium (Na+) ions out of the cell and potassium (K+) ions into the cell, effectively creating a concentration gradient across the neuronal membrane. Typically, for every three sodium ions pumped out, two potassium ions are brought in, resulting in a net loss of positive charge inside the neuron. This action contributes to the resting potential, which is generally around -70 millivolts in neurons, indicating that the inside of the cell is more negatively charged relative to the outside. The sodium-potassium pump is crucial for resetting the membrane potential after it has been altered during an action potential and ensuring that the neuron can respond appropriately to subsequent stimuli. While other mechanisms, such as potassium leak channels, do influence the resting potential by allowing potassium ions to flow more freely out of the cell, the sodium-potassium pump's active transport role is key for sustaining the gradients necessary for action potentials and overall neuronal excitability.

The sodium-potassium pump is instrumental in maintaining the resting membrane potential of neurons. This pump actively transports sodium (Na+) ions out of the cell and potassium (K+) ions into the cell, effectively creating a concentration gradient across the neuronal membrane. Typically, for every three sodium ions pumped out, two potassium ions are brought in, resulting in a net loss of positive charge inside the neuron.

This action contributes to the resting potential, which is generally around -70 millivolts in neurons, indicating that the inside of the cell is more negatively charged relative to the outside. The sodium-potassium pump is crucial for resetting the membrane potential after it has been altered during an action potential and ensuring that the neuron can respond appropriately to subsequent stimuli.

While other mechanisms, such as potassium leak channels, do influence the resting potential by allowing potassium ions to flow more freely out of the cell, the sodium-potassium pump's active transport role is key for sustaining the gradients necessary for action potentials and overall neuronal excitability.