Body tissues obtain oxygen from haemoglobin because of its dissociation in tissues caused by

Options

A. Low oxygen concentration and high carbon dioxide concentration
B. Low oxygen concentration
C. Low carbon dioxide concentration
D. High carbon dioxide concentration

Answer

**Step-by-Step Solution:**

1. **Understanding Hemoglobin Function**: Hemoglobin is a protein in red blood cells that binds to oxygen in the lungs and carries it to body tissues.

2. **Oxygen Binding in Lungs**: In the lungs, the partial pressure of oxygen (pO2) is high. This high concentration allows hemoglobin to bind readily with oxygen.

3. **Transport to Tissues**: As blood circulates to body tissues, the partial pressure of oxygen decreases. This lower pO2 in the tissues leads to the release of oxygen from hemoglobin.

4. **Role of Carbon Dioxide**: In addition to low oxygen levels, the partial pressure of carbon dioxide (pCO2) in tissues is higher. The increase in carbon dioxide concentration promotes the release of oxygen from hemoglobin.

5. **Bohr Effect**: The phenomenon where an increase in carbon dioxide and a decrease in pO2 causes hemoglobin to release oxygen more readily is known as the Bohr effect. This is represented by a rightward shift in the oxygen-hemoglobin dissociation curve.

6. **Conclusion**: Therefore, body tissues obtain oxygen from hemoglobin because of its dissociation in tissues, which is primarily caused by low oxygen concentration (low pO2) and high carbon dioxide concentration (high pCO2).

**Final Answer**: Body tissues obtain oxygen from hemoglobin because of its dissociation in tissues caused by low oxygen concentration (low pO2) and high carbon dioxide concentration (high pCO2).

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