Smooth muscles are also called involuntary muscles. Why?

Answer

### Step-by-Step Solution:

1. **Definition of Smooth Muscles**: Smooth muscles are a type of muscle tissue found in various internal organs and blood vessels. They are distinct from skeletal muscles and cardiac muscles.

2. **Location of Smooth Muscles**: Smooth muscles are primarily located in the walls of internal organs such as the digestive tract, blood vessels, and the reproductive and urinary systems. They play a crucial role in the functioning of these systems.

3. **Characteristics of Smooth Muscles**:
- **Non-Striated Appearance**: Unlike skeletal muscles, smooth muscles do not have a striped or striated appearance. They lack the alternating light and dark bands that are characteristic of striated muscles.
- **Involuntary Control**: Smooth muscles are classified as involuntary muscles, meaning they operate without conscious control. Their actions are automatic and are regulated by the autonomic nervous system.

4. **Function of Smooth Muscles**: Smooth muscles are responsible for various involuntary movements such as:
- **Peristalsis**: The wave-like contractions that move food through the digestive system.
- **Vasoconstriction and Vasodilation**: The contraction and relaxation of blood vessels to regulate blood flow and pressure.
- **Reproductive Functions**: Processes such as ovulation and contractions during childbirth.

5. **Comparison with Voluntary Muscles**: In contrast to smooth muscles, skeletal muscles are voluntary muscles that can be consciously controlled. For example, when lifting an object, the skeletal muscles are actively engaged and controlled by the individual.

6. **Conclusion**: Smooth muscles are called involuntary muscles because their actions occur automatically and are not under conscious control, making them essential for the functioning of various internal processes.