Unloading of oxygen is relatively more at which of the following areas

Options

A. Lungs
B. Smooth muscles
C. Skeletal muscles
D. Gills

Answer

To answer the question "Unloading of oxygen is relatively more at which of the following areas: lungs, smooth muscles, skeletal muscles, or gills?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Unloading**:
- Unloading refers to the process where oxygen is released from oxyhemoglobin in the blood. This occurs when blood flows through capillaries in metabolizing tissues.

2. **Identify Factors Influencing Unloading**:
- Several factors can enhance the unloading of oxygen from hemoglobin:
- **Increased Temperature**: Higher temperatures decrease the affinity of hemoglobin for oxygen, promoting unloading.
- **Increased Carbon Dioxide (CO2)**: Higher levels of CO2 in tissues lead to a lower pH (more acidic), which also decreases hemoglobin's affinity for oxygen.
- **Increased Metabolism**: Active tissues, such as skeletal muscles, have higher metabolic rates, resulting in increased CO2 production and heat generation.

3. **Evaluate the Options**:
- **Lungs**: Oxygen is loaded here, not unloaded.
- **Smooth Muscles**: While they do metabolize, they are not as active as skeletal muscles.
- **Skeletal Muscles**: These are highly active tissues that have increased temperature and CO2 production during exercise, leading to more oxygen unloading.
- **Gills**: Primarily involved in oxygen uptake from water, not unloading.

4. **Conclusion**:
- Given the factors that promote oxygen unloading, the area where unloading of oxygen is relatively more occurs in the **skeletal muscles** due to their high metabolic activity.

### Final Answer:
The unloading of oxygen is relatively more at **skeletal muscles**.