Conditions responsible for shifting of `O_2` dissociation curve away from Y-axis (Right side) are

Options

A. Low`pO_2`
B. High `pCO_2`
C. High temperature
D. All

Answer

To determine the conditions responsible for shifting the oxygen dissociation curve (ODC) away from the Y-axis (to the right), we need to analyze various factors that influence hemoglobin's affinity for oxygen. The ODC illustrates how the saturation of hemoglobin with oxygen changes in response to different partial pressures of oxygen (pO2).

### Step-by-Step Solution:

1. **Understanding the Oxygen Dissociation Curve (ODC)**:
- The ODC represents the relationship between the saturation of hemoglobin with oxygen and the partial pressure of oxygen (pO2).
- A rightward shift in the ODC indicates a decrease in hemoglobin's affinity for oxygen, meaning hemoglobin releases oxygen more readily to tissues.

2. **Identifying Conditions for Rightward Shift**:
- Several physiological conditions can lead to a rightward shift in the ODC:
- **Low pO2**: When the partial pressure of oxygen is low, hemoglobin's affinity for oxygen decreases, facilitating oxygen release.
- **High pCO2**: An increase in carbon dioxide concentration (pCO2) leads to a decrease in blood pH (acidosis), which also reduces hemoglobin's affinity for oxygen.
- **High Temperature**: Elevated body temperature can decrease the affinity of hemoglobin for oxygen, promoting oxygen release to active tissues.
- **Increased 2,3-DPG Levels**: 2,3-diphosphoglycerate (2,3-DPG) is a byproduct of glycolysis in red blood cells. Higher concentrations of 2,3-DPG reduce hemoglobin's affinity for oxygen, facilitating oxygen unloading.

3. **Conclusion**:
- All the mentioned factors (low pO2, high pCO2, high temperature, and high 2,3-DPG) contribute to the rightward shift of the oxygen dissociation curve.
- Therefore, the correct answer is that all these conditions are responsible for shifting the ODC to the right.

### Final Answer:
The conditions responsible for shifting the oxygen dissociation curve away from the Y-axis (to the right) are:
- Low pO2
- High pCO2
- High temperature
- High concentration of 2,3-DPG
Thus, the correct option is **all of the above**.

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