Which of the following is different from others in the absence of a muscular coat ?

Options

A. Arteries
B. Veins
C. Capillaries
D. Arterioles

Answer

To solve the question "Which of the following is different from others in the absence of a muscular coat?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding the Question**:
- The question asks which option lacks a muscular coat. A muscular coat refers to the smooth muscle layer found in blood vessels that helps regulate blood flow.

2. **Analyzing the Options**:
- **Option 1: Arteries**
- Arteries are blood vessels that carry oxygenated blood away from the heart. They have a thick muscular coat to withstand high pressure.
- **Conclusion**: Incorrect option, as arteries have a muscular coat.

- **Option 2: Veins**
- Veins are blood vessels that carry deoxygenated blood back to the heart. They also have a muscular coat, though it is thinner than that of arteries.
- **Conclusion**: Incorrect option, as veins have a muscular coat.

- **Option 3: Capillaries**
- Capillaries are the smallest blood vessels where the exchange of gases, nutrients, and waste occurs. They do not have a muscular coat; their walls are made of a single layer of endothelial cells.
- **Conclusion**: Correct option, as capillaries lack a muscular coat.

- **Option 4: Arterioles**
- Arterioles are small blood vessels that branch from arteries and lead to capillaries. They have a muscular coat that helps regulate blood flow.
- **Conclusion**: Incorrect option, as arterioles have a muscular coat.

3. **Final Answer**:
- The option that is different from the others in the absence of a muscular coat is **Option 3: Capillaries**.