Which electrolyte is most abundant in extracellular fluid?

The correct electrolyte that is most abundant in extracellular fluid is sodium. Sodium plays a crucial role in maintaining fluid balance, nerve transmission, and muscle function. In the body, the majority of sodium is found in the extracellular fluid, where it helps regulate osmotic pressure and influences the movement of water across cell membranes.

Sodium contributes to the overall osmolarity of extracellular fluid, which is essential for maintaining blood pressure and volume. Given its prevalence and importance, sodium is often referred to as the primary extracellular cation. This characteristic is vital for various physiological processes, including the conduction of electrical impulses in neurons and the contraction of muscles.

Understanding the role of sodium within extracellular fluid emphasizes its significance in electrolyte balance and overall homeostasis in the body.