What is meant by double blood circulation ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Double Blood Circulation**: Double blood circulation refers to the process in which blood circulates through the heart twice during one complete cycle. This means that blood passes through the heart two times before it completes a full circuit of the body.

2. **Components of Double Blood Circulation**:
- **Pulmonary Circulation**: This is the first part of double circulation. In pulmonary circulation, deoxygenated blood is transported from the heart to the lungs. Here, the blood receives oxygen and releases carbon dioxide. The oxygenated blood then returns to the heart.
- **Systemic Circulation**: This is the second part of double circulation. In systemic circulation, oxygenated blood is pumped from the heart to all other parts of the body. After delivering oxygen and nutrients to the tissues, the blood returns to the heart as deoxygenated blood.

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