What electrical charge does a cardiac cell have in its resting state?

In its resting state, a cardiac cell has a negative electrical charge. This condition occurs due to the difference in ion concentration inside and outside the cell membrane, primarily maintained by the sodium-potassium pump. The inside of the cell is more negative compared to the outside, mainly because of a higher concentration of potassium ions (K+) inside and sodium ions (Na+) outside.

This negative resting membrane potential is crucial for the heart's electrical activity, as it allows the cardiac cells to become depolarized in response to an electrical stimulus, leading to the generation of an action potential and, ultimately, heart contractions. Understanding this resting negative charge is fundamental for interpreting EKGs and recognizing cardiac rhythms.