Illustrate Nernst equilibrium potential for potassium ions
A complete motor neuron is removed from a frog and placed in normal physiological saline at 1 AM. The neuron is healthy. At 2 AM, the physiological saline bathing the neuron is removed and replaced with a modified physiological saline. The composition of the modified physiological saline is as follows: its potassium concentration is the same as the intracellular potassium concentration of the motor neuron; its sodium concentration is the same as the intracellular sodium concentration of the motor neuron; its total concentration of solutes (osmolarity) is the same as normal physiological saline. The modified physiological saline also contains molecules that block the flux of ions viathe sodium-potassium primary active transport pump. At 2:05 AM, the neuron is at rest and its membrane voltage is equal to the Nernst equilibrium potential for potassium ions at 2:05 AM. At 2:06 AM,
A. the value of the Nernst equilibrium potential for sodium ions for the neuron is less than +10 millivolts.
B. an increase in potassium conductance will lead to no change in the membrane voltage.
C. an increase in sodium conductance will lead to a decrease in the amount of intracellular sodium