Final answer:
At a membrane potential of -75mV, positive ions like sodium (Na+) tend to move into the cell, progressing towards depolarization. This potential is close to the resting potential of -70mV, with the potential for an action potential initiation under the right stimulus.
Step-by-step explanation:
Under standard ionic conditions with a membrane potential of -75mV, there is a tendency for positive currents to enter the cell. This involves the movement of Na+ ions into the cell through leakage channels and voltage-gated channels, changing the internal charge closer to positive values, a process known as depolarization. During the resting state, leakage channels, along with the Na+/K+ pump, help in maintaining the resting potential by balancing the flux of Na+ and K+ across the membrane.
The -75mV potential indicates that the cell is just below the typical resting membrane potential of -70mV. This suggests that the cell is in a resting state but very close to initiating an action potential should the necessary stimulus be applied. When the threshold is reached, current flow in the form of an action potential could be triggered, causing a rapid influx of Na+ ions until the membrane potential goes positive, reaching approximately +30mV.