The passage of water and its soluble compounds out of arteriolar end is due to  

Options

A. collaidal osmotic pressure
B. osmotic pressure
C. hydrostatic pressure
D. all the above

Answer

To answer the question regarding the passage of water and its soluble compounds out of the arteriolar end, we need to analyze the different types of pressures involved in this process.

### Step-by-Step Solution:

1. **Understanding the Types of Pressure**:
- **Colloidal Osmotic Pressure**: This pressure is induced by proteins, particularly albumin, in the plasma. It generally works to retain water within the blood vessels by drawing water in rather than allowing it to exit.
- **Osmotic Pressure**: This pressure is related to the concentration of solutes in a solution. It prevents the flow of water out of a solution with a higher solute concentration. Thus, it also tends to retain water within the blood vessels.
- **Hydrostatic Pressure**: This is the pressure exerted by a fluid at rest, which is influenced by gravity. In the context of blood vessels, hydrostatic pressure is generated by the pumping action of the heart and is responsible for pushing water and soluble compounds out of the arterioles into the surrounding tissues.

2. **Analyzing the Question**:
- The question asks about the passage of water and its soluble compounds out of the arteriolar end. This process is primarily driven by hydrostatic pressure, which pushes the fluid out of the blood vessels.

3. **Evaluating the Options**:
- **Colloidal Osmotic Pressure**: Incorrect, as it tends to draw water into the blood vessels.
- **Osmotic Pressure**: Incorrect, as it also works to retain water within the blood vessels.
- **Hydrostatic Pressure**: Correct, as it is responsible for pushing water and soluble compounds out of the arterioles.
- **All of the Above**: Incorrect, as not all the pressures listed facilitate the movement of water out of the arterioles.

4. **Conclusion**:
- The correct answer is **Hydrostatic Pressure** (Option C), as it is the primary force driving the passage of water and soluble compounds out of the arteriolar end.