How does the level of carbon dioxide (\(\mathrm{CO_2}\)) in a person's blood change when they hyperventilate?

• A. It increases because less \(\mathrm{CO_2}\) is exhaled.
• B. It increases because more \(\mathrm{CO_2}\) is produced during hyperventilation.
• C. It decreases because excess \(\mathrm{CO_2}\) is exhaled rapidly.
• D. It remains unchanged because breathing rate does not affect \(\mathrm{CO_2}\) levels.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the process of hyperventilation. Hyperventilation is characterized by rapid and deep breathing, which increases the rate of gas exchange in the lungs.
2. Step 2: Recall the role of carbon dioxide (\(\mathrm{CO_2}\)) in the blood. \(\mathrm{CO_2}\) is a waste product of cellular respiration and is transported in the blood to the lungs for exhalation.
3. Step 3: Analyze the effect of hyperventilation on \(\mathrm{CO_2}\) levels. During hyperventilation, the rapid breathing causes an increased exhalation of \(\mathrm{CO_2}\), leading to a decrease in its concentration in the blood.
4. Step 4: Consider the physiological consequences of decreased \(\mathrm{CO_2}\) levels. A drop in blood \(\mathrm{CO_2}\) can lead to respiratory alkalosis, where the blood becomes less acidic due to reduced \(\mathrm{CO_2}\) levels.
5. Step 5: Evaluate the given options. The correct answer is: 'It decreases because excess \(\mathrm{CO_2}\) is exhaled rapidly,' as hyperventilation results in the rapid removal of \(\mathrm{CO_2}\) from the blood.