tunica media will be absent in the Wall of

Options

A. arteries
B. vena cava
C. capillaries
D. veins

Answer

To determine where the tunica media is absent, we need to understand what the tunica media is and where it is typically found in blood vessels.

### Step-by-Step Solution:

1. **Definition of Tunica Media**:
- The tunica media is the middle layer of blood vessels, primarily composed of smooth muscle and elastic fibers. It plays a crucial role in regulating blood pressure and flow by constricting or dilating the vessel.

2. **Location of Tunica Media**:
- The tunica media is present in arteries and veins, where it helps manage blood flow and pressure.

3. **Characteristics of Capillaries**:
- Capillaries are the smallest blood vessels in the body. They have very thin walls, consisting of only a single layer of endothelial cells. This thin structure allows for efficient exchange of gases, nutrients, and waste between blood and tissues.

4. **Absence of Tunica Media in Capillaries**:
- Due to their extremely thin walls, capillaries do not require a tunica media. The absence of this layer is because capillaries are designed for exchange rather than for regulating blood pressure or flow.

5. **Conclusion**:
- Therefore, the tunica media is absent in the walls of capillaries.

### Final Answer:
The tunica media will be absent in the wall of **capillaries**.

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