Ventricles are thick-walled as compared to atrium because -

Options

A. it is to receive blood from atria
B. It is present on the posterior side
C. It is to pump blood
D. None

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of the Heart:**
- The heart consists of four chambers: two atria (upper chambers) and two ventricles (lower chambers).
- The atria receive blood, while the ventricles pump blood out of the heart.

2. **Comparing the Walls of the Atria and Ventricles:**
- The walls of the ventricles are significantly thicker than those of the atria.
- This difference in thickness is crucial for their respective functions.

3. **Function of the Ventricles:**
- Ventricles are responsible for pumping blood to different parts of the body.
- The left ventricle pumps oxygenated blood to the entire body through the aorta, while the right ventricle pumps deoxygenated blood to the lungs.

4. **Need for Stronger Contraction:**
- To effectively pump blood throughout the body, especially against gravity and resistance, the ventricles need to generate a strong muscular contraction.
- A thicker wall allows for stronger contractions, which is essential for pumping blood efficiently.

5. **Role of the Aorta:**
- The aorta is the main artery that carries blood from the left ventricle to the rest of the body.
- It branches into smaller arteries to supply blood to various organs and tissues.

6. **Conclusion:**
- The thickness of the ventricular walls, particularly the left ventricle, is necessary for their role in pumping blood throughout the body, which is why they are thicker compared to the atria.

**Final Answer:**
Ventricles are thick-walled as compared to the atrium because they need to generate strong contractions to pump blood effectively to the body parts.

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