Sodium reabsorption from the distal tubule will be increased if there is an increase in

Options

A. ADH
B. plasma volume
C. mean arterial pressure
D. plasma potassium concentration

Answer

To solve the question regarding sodium reabsorption from the distal tubule, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Sodium Reabsorption**: Sodium reabsorption is a crucial process that occurs in the kidneys, particularly in the nephron's distal tubule. It plays a significant role in maintaining electrolyte balance and blood pressure.

2. **Identifying the Factors Affecting Sodium Reabsorption**: Sodium reabsorption can be influenced by various factors, including hormonal regulation and blood pressure.

3. **Mean Arterial Pressure (MAP)**: The mean arterial pressure is the average pressure in a person's arteries during one cardiac cycle. It is calculated using the formula:
\[ \text{Mean Arterial Pressure} = \text{Diastolic Pressure} + \frac{1}{3}(\text{Systolic Pressure} - \text{Diastolic Pressure}) \]
This indicates the overall blood flow and pressure exerted on the walls of the arteries.

4. **Relationship Between MAP and Sodium Reabsorption**: An increase in mean arterial pressure generally indicates an increase in blood flow and renal perfusion. This can stimulate the kidneys to reabsorb more sodium.

5. **Role of the Renin-Angiotensin-Aldosterone System (RAAS)**: The renal system regulates blood pressure through the renin-angiotensin-aldosterone system. When blood pressure drops, the kidneys release renin, which leads to the production of angiotensin II. Angiotensin II stimulates the adrenal glands to release aldosterone.

6. **Aldosterone's Effect on Sodium Reabsorption**: Aldosterone increases sodium reabsorption in the distal tubules of the nephron. Therefore, if there is an increase in mean arterial pressure, it can lead to increased levels of aldosterone, which in turn enhances sodium reabsorption.

7. **Conclusion**: Thus, sodium reabsorption from the distal tubule will be increased if there is an increase in mean arterial pressure.

### Final Answer:
Sodium reabsorption from the distal tubule will be increased if there is an increase in **mean arterial pressure**.

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