Final answer:
The correct answer to the question on blood gas changes due to in vitro glycolysis is 'd', resulting in a fall in pH and rise in PCO₂. This is because red blood cells continue to consume oxygen and produce carbon dioxide after the blood sample is taken, which, if not measured immediately, leads to changes in blood gas levels.The right answer is d)
Step-by-step explanation:
The question concerns the changes in blood gas composition due to in vitro glycolysis if blood gas measurements are not performed promptly after sampling. In vitro glycolysis, which is the breakdown of glucose by enzymes in the sample, causes a continuing consumption of oxygen (PO₂) and production of carbon dioxide (PCO₂). As the red blood cells continue to metabolize glucose, they consume oxygen and produce carbon dioxide, leading to a fall in pH and a rise in PCO₂.
In a clinical context, the correct answer is option 'd', which indicates that there will be a fall in pH (becoming more acidic due to the production of metabolic acids like lactic acid) and a rise in PCO₂ (because CO₂ is a product of cellular respiration that continues after the blood is drawn if it is not immediately analyzed).
It is important not to confuse these changes with the physiological responses of the body to active or resting states. The in vitro effects occur after sampling and are due to cellular respiration in the extracted blood, not the metabolic state of the person from whom the sample was taken.