Unstriated muscles in the vertebrates are also called

Options

A. Cardiac muscles
B. Skeletal muscles
C. Tonal muscles
D. Visceral or smooth muscles

Answer

**Step-by-Step Solution:**

1. **Understanding Muscle Types**: In vertebrates, muscles can be categorized into three main types: striated (skeletal), cardiac, and unstriated (smooth).

2. **Identifying Unstriated Muscles**: Unstriated muscles are also known as involuntary muscles. This means that their actions are not under conscious control.

3. **Differentiating Muscle Types**:
- **Cardiac Muscles**: These are striated muscles found in the heart and are also involuntary.
- **Skeletal Muscles**: These are striated muscles attached to bones, and their functions are voluntary, meaning they are controlled consciously.
- **Unstriated Muscles**: These are also referred to as smooth muscles or visceral muscles. They do not have the striations (stripes) that are characteristic of skeletal muscles.

4. **Examples of Unstriated Muscles**: Smooth muscles are found in various organs such as the walls of the stomach, esophagus, bronchi, and the iris of the eye.

5. **Conclusion**: Based on the definitions and examples, unstriated muscles in vertebrates are commonly referred to as **visceral muscles** or **smooth muscles**.

**Final Answer**: Unstriated muscles in vertebrates are also called **visceral muscles** or **smooth muscles**.

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