Smooth muscles are

Options

A. involuntary, spindle shaped, uninucleated, unbranched
B. voluntary, multinucleate and cylindrical
C. involuntary, cylindrical, mutinucleate
D. voluntary, branched, uninuclear

Answer

**Step-by-Step Solution:**

1. **Understanding Smooth Muscles**: Smooth muscles are a type of muscle tissue found in various organs and systems of the body. They are responsible for involuntary movements, such as the contraction of blood vessels and the movement of food through the digestive tract.

2. **Characteristics of Smooth Muscles**:
- **Involuntary Control**: Smooth muscles are not under conscious control; they function automatically.
- **Spindle-Shaped**: The cells of smooth muscle are elongated and taper at both ends, resembling a spindle.
- **Uninucleated**: Each smooth muscle cell contains a single nucleus.
- **Unbranched**: Smooth muscle fibers do not branch; they are long and smooth.

3. **Comparison with Other Muscle Types**: Unlike skeletal muscles, which are voluntary, striated, and multinucleated, smooth muscles are non-striated and have a single nucleus. Cardiac muscles, on the other hand, are branched and striated, with multiple nuclei.

4. **Conclusion**: Based on the characteristics outlined, the correct description of smooth muscles is that they are involuntary, spindle-shaped, uninucleated, and unbranched.

5. **Final Answer**: The correct option is **A**: involuntary, spindle shaped, uninucleated, unbranched.

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