In urinary system, aldosterone takes part in retention and reabsorption of

Options

A. `Ca^(2+)`
B. `K^(+)`
C. `Na^(+)`
D. Water

Answer

**Step-by-Step Solution:**

1. **Understanding Aldosterone**: Aldosterone is a hormone produced by the adrenal glands, specifically from the outer part known as the adrenal cortex. It is classified as a mineralocorticoid hormone.

2. **Function of Aldosterone**: The primary role of aldosterone in the urinary system is to regulate the balance of electrolytes in the body, particularly sodium and potassium.

3. **Retention and Reabsorption**: Aldosterone promotes the retention (or reabsorption) of sodium ions (Na+) in the kidneys. This means that when aldosterone is present, the kidneys will reabsorb more sodium back into the bloodstream instead of excreting it in urine.

4. **Effect on Water Retention**: As sodium is reabsorbed, water follows due to osmosis. This leads to an increase in blood volume and blood pressure.

5. **Potassium Excretion**: While aldosterone promotes sodium retention, it also encourages the excretion of potassium ions (K+) from the bloodstream into the urine.

6. **Conclusion**: Therefore, in the context of the urinary system, aldosterone takes part in the retention and reabsorption of sodium ions.

**Final Answer**: Aldosterone takes part in the retention and reabsorption of sodium ions in the urinary system.

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