Topics:
Animal Nutrition, Animal Refresher
Major Ions in Intra-Cellular Fluid
Major cation & anion in Intra-cellular fluid (ICF) are:
- $Na^{+}$, $Cl^{-}$
- $K^{+}$, $PO_{4}^{-}$ — Correct Answer
- $Na^{+}$, $PO_{4}^{-}$
- None
Explanation:
Correct Answer: K⁺, PO₄³⁻
The major cation in Intra-Cellular Fluid (ICF) is K⁺ (Potassium) and the major anion is PO₄³⁻ (Phosphate). ICF accounts for about two-thirds of total body water and is the site of most metabolic reactions.
Comparison of Fluid Compartments
| Parameter | ECF | ICF |
|---|---|---|
| Major cation | Na⁺ | K⁺ |
| Major anion | Cl⁻ | PO₄³⁻ |
| Proportion of body water | ~1/3 | ~2/3 |
Key Points
- K⁺ is actively pumped into cells by Na⁺/K⁺-ATPase, maintaining higher intracellular concentration.
- Phosphate is critical for ATP synthesis, nucleic acids, and phospholipid membranes — hence its high concentration inside cells.
- Dietary potassium deficiency leads to hypokalaemia — muscle weakness, cardiac arrhythmias.
Why Other Options Are Wrong
- Na⁺, Cl⁻ → these are the ECF ions.
- Na⁺, PO₄³⁻ → Na⁺ is extracellular; PO₄³⁻ is intracellular — mixed pair.
- None → ICF has definitive major ions.
📚 About this Topic — Animal Nutrition
This multiple choice question is from Animal Nutrition, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Nutrition to strengthen your preparation.
