Cardiac muscles as compared to skeletal muscles can contract

Options

A. Quickly and do not get fatigued
B. slowly and do not get fatigued
C. Quickly and get fatigued
D. Slowly and get fatigued

Answer

### Step-by-Step Solution:

1. **Understanding Cardiac and Skeletal Muscles**:
- Cardiac muscles are specialized muscles found in the heart, while skeletal muscles are attached to bones and facilitate movement.

2. **Contraction Mechanism**:
- Cardiac muscles contract in a coordinated manner due to the presence of intercalated discs. These discs allow for rapid transmission of contraction signals between muscle fibers.

3. **Nature of Contraction**:
- The contraction of cardiac muscles occurs as a single unit, meaning all fibers contract simultaneously. This is known as rhythmic contraction.

4. **Fatigue Resistance**:
- Cardiac muscles are designed to work continuously without fatigue. This is attributed to their rich blood supply, high levels of cytoplasmic glycogen, and numerous mitochondria, which provide energy.

5. **Comparative Analysis**:
- When comparing cardiac muscles to skeletal muscles, we find that cardiac muscles contract quickly and do not get fatigued, unlike skeletal muscles which can tire out after prolonged use.

6. **Evaluating Options**:
- The options provided in the question can be evaluated based on the characteristics discussed:
- Option 1: Quickly and do not get fatigued (Correct)
- Option 2: Slowly and do not get fatigued (Incorrect)
- Option 3: Quickly and get fatigued (Incorrect)
- Option 4: Slowly and get fatigued (Incorrect)

7. **Conclusion**:
- The correct answer is that cardiac muscles, as compared to skeletal muscles, can contract quickly and do not get fatigued.