Which statement best describes the primary function of the Na+/K+-ATPase pump?

Which statement best describes the primary function of the Na+/K+-ATPase pump?

• A. It directly generates action potentials.
• B. It transports neurotransmitters across the synaptic cleft.
• C. It actively pumps Na+ and K+ across the membrane to maintain ion gradients.
• D. It forms part of the myelin sheath.

Answer: (C)

Active maintenance of sodium and potassium gradients across the cell membrane powered by ATP is the key idea here. The Na+/K+-ATPase moves three Na+ ions out of the cell and two K+ ions into the cell, against their concentration gradients. This keeps the electrochemical gradients that establish and sustain the resting membrane potential and provide the driving force for many other transport processes and for repolarization after action potentials. It does not directly generate action potentials—that's driven by voltage-gated Na+ channels—nor does it shuttle neurotransmitters across the synapse, and it isn’t involved in forming the myelin sheath. Its activity also adds a small net outward current, helping keep the cell interior relatively negative.

Active maintenance of sodium and potassium gradients across the cell membrane powered by ATP is the key idea here. The Na+/K+-ATPase moves three Na+ ions out of the cell and two K+ ions into the cell, against their concentration gradients. This keeps the electrochemical gradients that establish and sustain the resting membrane potential and provide the driving force for many other transport processes and for repolarization after action potentials. It does not directly generate action potentials—that's driven by voltage-gated Na+ channels—nor does it shuttle neurotransmitters across the synapse, and it isn’t involved in forming the myelin sheath. Its activity also adds a small net outward current, helping keep the cell interior relatively negative.