What is the typical intracellular concentration of sodium (Na+) in mEq/L?

The typical intracellular concentration of sodium (Na+) is actually around 14 mEq/L. In physiological terms, sodium is predominantly found outside of the cell, with a significantly lower concentration within the cell. This low intracellular sodium concentration is crucial for maintaining the electrochemical gradient across the cell membrane, which is vital for processes such as action potentials in neurons and muscle contractions.

The concept of sodium distribution is fundamental in physiology, as it reflects the activity of the sodium-potassium pump (Na+/K+ ATPase), which actively transports sodium out of the cell and potassium (K+) into the cell. This pump helps to maintain the necessary concentration gradients for normal cellular functions. Therefore, understanding that intracellular sodium is around 14 mEq/L is key in the context of cellular physiology and the functioning of various cellular mechanisms.