What are the functions of double circulation ?

Options

A. Systemic circulation of nutrients and gases.
B. Absorption of harmful substances
C. Carries blood from intestine of the kidney
D. All of these

Answer

**Step-by-Step Text Solution:**

1. **Understanding Double Circulation**:
Double circulation refers to the process in which blood circulates through the heart twice during one complete cycle. It consists of two separate circuits: the pulmonary circuit and the systemic circuit.

2. **Components of the Heart**:
The human heart has four chambers: the right atrium, right ventricle, left atrium, and left ventricle. Blood flows through these chambers in a specific order.

3. **Pulmonary Circulation**:
Deoxygenated blood from the body returns to the right atrium, moves to the right ventricle, and is then pumped through the pulmonary artery to the lungs. In the lungs, carbon dioxide is exchanged for oxygen, resulting in oxygenated blood.

4. **Systemic Circulation**:
The oxygenated blood returns to the left atrium, moves to the left ventricle, and is pumped out through the aorta to the rest of the body. This circulation delivers oxygen and nutrients to the cells and tissues.

5. **Functions of Double Circulation**:
- **Systemic Circulation of Nutrients and Gases**: It ensures that oxygen and nutrients are delivered to body cells while removing carbon dioxide and other waste products.
- **Absorption of Harmful Substances**: While double circulation itself does not directly absorb harmful substances, it plays a role in transporting them to organs like the liver for detoxification.
- **Carries Blood from Intestine to Kidney**: The systemic circulation also includes the transport of blood from the intestines to the kidneys, where waste products are filtered out.

6. **Conclusion**:
The primary function of double circulation is to efficiently transport oxygenated blood to the body and return deoxygenated blood to the lungs for re-oxygenation. Therefore, the correct answer to the question is that it facilitates systemic circulation of nutrients and gases.

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