Correct one of the following regarding partial pressure (mm in Hg) of `O_2` and `CO_2` in systemic veins respectively is

Options

A. 40 and 45
B. 95 and 40
C. 104 and 40
D. 100 and 140

Answer

To solve the question regarding the partial pressures of O2 and CO2 in systemic veins, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Partial Pressure**:
- Partial pressure refers to the pressure exerted by a single type of gas in a mixture of gases. It is measured in mmHg (millimeters of mercury).

2. **Identify the Context**:
- The question specifically asks about the partial pressures of O2 (oxygen) and CO2 (carbon dioxide) in systemic veins, which are the blood vessels that carry deoxygenated blood back to the heart from the body tissues.

3. **Know the Normal Values**:
- In systemic veins, the typical partial pressure of O2 is around 95 mmHg, while the partial pressure of CO2 is approximately 40 mmHg. This reflects the exchange of gases that occurs in the tissues, where oxygen is used and carbon dioxide is produced.

4. **Write Down the Values**:
- For O2: 95 mmHg
- For CO2: 40 mmHg

5. **Select the Correct Option**:
- The question asks for the values respectively. Therefore, the correct answer is that the partial pressure of O2 is 95 mmHg and that of CO2 is 40 mmHg.

6. **Conclusion**:
- The correct statement regarding the partial pressures of O2 and CO2 in systemic veins is: O2 = 95 mmHg and CO2 = 40 mmHg.

### Final Answer:
The correct option is that the partial pressures of O2 and CO2 in systemic veins are 95 mmHg and 40 mmHg, respectively.

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