Which of the following is a typical value for the systemic tissue partial pressure of carbon dioxide (CO_2) in mmHg?

• A. 100 mmHg
• B. 23 mmHg
• C. 46 mmHg
• D. 75 mmHg

Answer: (C)

Verified step by step guidance

1. Understand that the systemic tissue partial pressure of carbon dioxide (CO_2) refers to the pressure exerted by CO_2 in the tissues after it has been produced by cellular metabolism and before it is transported back to the lungs.
2. Recall typical physiological values: arterial blood usually has a CO_2 partial pressure around 40 mmHg, while venous blood, which reflects tissue conditions, has a higher CO_2 partial pressure due to CO_2 release from cells.
3. Recognize that the systemic tissue partial pressure of CO_2 is generally higher than arterial blood but lower than the maximum possible pressure, often around 45-46 mmHg.
4. Compare the given options (100 mmHg, 23 mmHg, 46 mmHg, 75 mmHg) to typical physiological ranges, noting that 46 mmHg fits well within the expected range for tissue CO_2 partial pressure.
5. Conclude that 46 mmHg is the typical value for systemic tissue partial pressure of CO_2 based on physiological data and understanding of gas exchange.