Membrane physiology: resting potential: practice question

The best answer is C, Potassium. At rest, neuronal membranes are most permeable to potassium through leak channels, so the resting potential lies close to the potassium equilibrium potential.

Sodium dominates the rapid depolarization phase rather than resting potential.

Calcium is tightly regulated and has lower resting permeability.

Chloride contributes in some cells but is not the principal determinant here.

It tests Membrane physiology: resting potential in Physiology. Sodium permeability rises sharply during the action potential upstroke.

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

For each system, sketch the key graph (pressure–volume loop, oxygen dissociation curve, nephron handling) and explain it aloud. Then use the flashcards and the other Physiology questions on this site to test what stuck.

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.