In vertebrates the myocardium refers to

Options

A. Skeletal muscles
B. Muscular wall of heart
C. Cells of pericardium
D. Fluid of pericardium

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Myocardium":**
- The term "myocardium" can be broken down into two parts: "myo" and "cardium."
- "Myo" typically refers to muscle, while "cardium" refers to the heart.

2. **Identifying the Function of Myocardium:**
- The myocardium is specifically the muscular layer of the heart responsible for contracting and pumping blood throughout the body.

3. **Analyzing the Options:**
- **Option A: Skeletal muscles** - These are muscles attached to bones and are not part of the heart structure.
- **Option B: Muscular wall of the heart** - This directly corresponds to the definition of myocardium, as it is the muscle layer of the heart.
- **Option C: Cells of pericardium** - The pericardium is the protective covering of the heart, made up of epithelial tissue, not muscle tissue.
- **Option D: Fluid of pericardium** - This refers to the fluid that lubricates the pericardial cavity, which is not related to the muscular structure of the heart.

4. **Conclusion:**
- Based on the breakdown of the term and the analysis of the options, the correct answer is **Option B: Muscular wall of the heart**.

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