Which one of the following component of urine in a healthy human does not differ much in concentration from that of blood plasma

Options

A. `NH_(4)^(+)`
B. `K^(+)`
C. `Na^(+)`
D. `SO_(4)^(2-)`

Answer

To solve the question of which component of urine in a healthy human does not differ much in concentration from that of blood plasma, we can analyze each option provided:

1. **NH4+ ions (Ammonium ions)**:
- Ammonium ions are toxic in their free form and are usually found in lower concentrations in blood plasma. The kidneys excrete a higher concentration of ammonium ions in urine to eliminate this toxicity. Therefore, this option is incorrect.

2. **K+ ions (Potassium ions)**:
- Potassium ions are primarily intracellular and are found in higher concentrations inside cells compared to blood plasma. The kidneys regulate potassium levels, and typically, the concentration of potassium in urine is higher than that in blood plasma. Thus, this option is also incorrect.

3. **Na+ ions (Sodium ions)**:
- Sodium ions are extracellular and their concentration in blood plasma is relatively high. The kidneys maintain sodium balance, and the concentration of sodium in urine is often similar to that in blood plasma. Therefore, this option is correct.

4. **SO4^2- ions (Sulfate ions)**:
- Sulfate ions are primarily derived from amino acids and are usually present in lower concentrations in urine compared to blood plasma. They are typically excreted in minute amounts in urine, especially during normal physiological conditions. Hence, this option is incorrect.

Based on this analysis, the correct answer is **Na+ ions (Sodium ions)**, as they do not differ much in concentration between urine and blood plasma in a healthy human.

### Summary of Steps:
1. Analyze the concentration of NH4+ ions in blood plasma and urine.
2. Analyze the concentration of K+ ions in blood plasma and urine.
3. Analyze the concentration of Na+ ions in blood plasma and urine.
4. Analyze the concentration of SO4^2- ions in blood plasma and urine.
5. Determine which component has similar concentrations in both blood plasma and urine.