What is the typical extracellular concentration of potassium (K+) in mEq/L?

The typical extracellular concentration of potassium (K+) is around 4 mEq/L. This concentration is critical for maintaining the electrochemical gradient across the cell membrane, which is essential for functions like nerve impulse transmission and muscle contraction. Potassium plays a significant role in cellular activities, and its concentration must be tightly regulated by mechanisms such as the sodium-potassium pump, which helps maintain the appropriate intracellular and extracellular levels of sodium and potassium.

In contrast, higher concentrations like 140 mEq/L represent an intracellular concentration rather than extracellular, and 14 mEq/L, as well as 2.4 mEq/L, are significantly lower than the normal extracellular range. The extracellular concentration of potassium is crucial for physiological processes, including maintaining resting membrane potential and overall cellular function; thus, the correct value reflects the importance of potassium in a healthy physiological state.