which of the following factors will not favour the movement of oxygen from blood in Systematic capillaries to tissues?

Options

A. high DPG levels in blood
B. high `pCO_2` in tissues
C. high `H^+` in blood
D. low `pCO_2` in tissues

Answer

To determine which factor will not favor the movement of oxygen from blood in systemic capillaries to tissues, we need to analyze the factors that influence oxygen transport and the hemoglobin dissociation curve.

### Step-by-Step Solution:

1. **Understanding Oxygen Transport**: Oxygen is transported in the blood primarily bound to hemoglobin. The release of oxygen from hemoglobin into tissues is influenced by several factors, including pH, temperature, carbon dioxide levels, and the presence of 2,3-DPG.

2. **Hemoglobin Dissociation Curve**: The hemoglobin dissociation curve illustrates how readily hemoglobin binds to oxygen and releases it. A rightward shift in the curve indicates that hemoglobin releases oxygen more readily (favoring oxygen movement to tissues), while a leftward shift indicates that hemoglobin holds onto oxygen more tightly (not favoring oxygen movement).

3. **Factors Affecting Oxygen Release**:
- **High levels of CO2**: This increases the release of oxygen (right shift).
- **Low pH (high H+ concentration)**: This also promotes oxygen release (right shift).
- **High temperature**: This favors oxygen release as well (right shift).
- **High levels of 2,3-DPG**: This decreases hemoglobin's affinity for oxygen, promoting its release (right shift).

4. **Identifying the Non-Favorable Factor**: The question asks for the factor that does NOT favor the movement of oxygen from blood to tissues. A low pCO2 in tissues would mean that the tissues are not producing much carbon dioxide, which would lead to a leftward shift in the dissociation curve, making hemoglobin hold onto oxygen more tightly. This would not favor the movement of oxygen into the tissues.

5. **Conclusion**: Among the options, the factor that will not favor the movement of oxygen from blood in systemic capillaries to tissues is **low pCO2 in tissues**.

### Final Answer:
The correct option is **low pCO2 in tissues**.

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