Which ions are classified as cations in bodily fluids?

Cations are positively charged ions typically found in bodily fluids and play crucial roles in various physiological processes, including fluid balance, muscle contractions, and nerve impulse transmission. Sodium (Na) and magnesium (Mg) are prime examples of cations. Sodium is particularly significant in maintaining osmotic pressure and fluid balance in the body, while magnesium is vital for enzymatic reactions and muscle function.

The presence of cations like sodium and magnesium helps create an electrochemical gradient necessary for cellular functions. Cations attract negatively charged ions, or anions, to maintain electrical neutrality in bodily fluids.

In contrast, options referring to anions, non-conductive liquids, or proteins in plasma do not correctly identify ions classified as cations or their roles in bodily fluids. Cations specifically refer to positively charged entities, which distinctly includes sodium and magnesium.