Item #9 of 10

While at rest, the higher concentration of sodium outside the neuron and the negativity of charge inside the neuron attracts sodium into the neuron. In spite of this, the greater concentration of sodium in the extracellular fluid is maintained by _______________.

		actively pumping Na+ out of the neuron;
		transporting two sodium ions out of the neuron in exchange for every three potassium ions they transported in;
		transporting three sodium ions out of the neuron in exchange for every two potassium ions transported in.;
		both a and b are correct;
		both a and c are correct;

CORRECT - Yes, the passive forces that draw sodium into the resting neuron are actively counteracted by transporting three sodium ions out of the neuron for every two potassium ions transported into the neuron.

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