Which of the following is the major cation of the extracellular fluids of vertebrates?Multiple choice question.PotassiumSodiumMagnesiumCalcium

Breakdown of the Problem

We need to identify the major cation in the extracellular fluids of vertebrates among the given options: Potassium, Sodium, Magnesium, and Calcium.

Relevant Concepts

• Cation Definition: A cation is a positively charged ion.
• Extracellular Fluid Composition: Extracellular fluid in vertebrates primarily contains cations that help in various physiological functions, including nerve conduction and muscle contraction.

Analysis and Detail

1. Potassium (K⁺): Predominantly found inside cells (intracellular fluid), not in extracellular fluid.
2. Sodium (Na⁺): Major cation found in extracellular fluid; essential for maintaining osmotic balance and electrical gradients in nerve action.
3. Magnesium (Mg²⁺): Present but not predominant in extracellular fluid.
4. Calcium (Ca²⁺): Important for muscle contractions and signaling but is lower in concentration than sodium in extracellular fluid.

Verify and Summarize

Sodium is the most abundant cation in extracellular fluid and plays crucial roles in maintaining fluid balance and participating in action potentials in nerve cells.

Final Answer

Sodium is the major cation of the extracellular fluids of vertebrates.