Which of the two lie deeper under the skin : arteries or veins ?

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which blood vessels, arteries or veins, lie deeper under the skin.

2. **Defining Arteries and Veins**:
- **Arteries**: These are blood vessels that carry oxygenated blood away from the heart to the tissues of the body. They are generally thicker and more muscular than veins.
- **Veins**: These are blood vessels that carry deoxygenated blood back to the heart. They are usually thinner and have valves to prevent backflow.

3. **Location of Arteries**: Arteries are located deeper within the body. This is because they are under higher pressure due to the force with which the heart pumps blood through them.

4. **Location of Veins**: Veins are located closer to the surface of the skin. They are more superficial and can often be seen as bluish or greenish lines on the skin, especially in the arms and legs.

5. **Reason for the Difference in Depth**: The deeper location of arteries is a protective adaptation. Since arteries carry oxygen-rich blood and are under high pressure, being deeper helps prevent damage and excessive blood loss in case of injury. In contrast, veins are under lower pressure and can afford to be closer to the surface.

6. **Conclusion**: Based on the information, arteries lie deeper under the skin compared to veins.

**Final Answer**: Arteries lie deeper under the skin than veins.

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