List two structural peculiarities of cardiac muscle fibres.

Explanation

**Step-by-Step Solution:**

1. **Identify the Type of Muscle**: Cardiac muscle fibers are a type of muscle found in the heart. They are responsible for involuntary contractions that pump blood throughout the body.

2. **Structural Peculiarity 1 - Intercalated Discs**: One of the key structural features of cardiac muscle fibers is the presence of intercalated discs. These discs are specialized connections between adjacent cardiac muscle cells that allow for rapid communication and synchronization of contractions. They have a zigzag shape, which helps in the mechanical and electrical coupling of the cells.

3. **Structural Peculiarity 2 - Oblique Bridges**: Another important structural feature is the presence of oblique bridges between the cardiac muscle fibers. These connections facilitate the coordinated contraction of the heart muscle, ensuring that the heart beats in a rhythmic manner.

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