Final answer:
Sodium and potassium are the cations primarily responsible for controlling body water distribution, with sodium influencing extracellular fluids and potassium being key for cellular functions.
Step-by-step explanation:
The cations responsible for controlling body water distribution are sodium and potassium.These two electrolytes play key roles in the regulation of fluid balance within the body. Sodium ions are mainly found in extracellular fluids and are crucial for controlling blood volume, whereas potassium ions are predominantly located inside cells and are essential for maintaining cellular function. The balance and transport of these ions across cell membranes are vital for various physiological processes, such as nerve impulse transmission, muscle contraction, and maintaining the balance of other electrolytes.