JBL EMT Practice Exam

In the normal drive to breathe, what happens when arterial carbon dioxide levels increase?

1. pH of the cerebrospinal fluid increases.

2. Production of oxygen decreases.

3. Rate and depth of breathing decrease.

4. Rate and depth of breathing increase.

The correct answer is: pH of the cerebrospinal fluid increases.

When arterial carbon dioxide levels increase, the body responds by increasing the pH of the cerebrospinal fluid, making it more alkaline. This process, known as respiratory alkalosis, helps to restore the balance of carbon dioxide and prevent an excessive buildup in the blood. Choices B and C are incorrect because the body does not decrease oxygen production or decrease the rate and depth of breathing in response to high carbon dioxide levels. Choice D is incorrect because an increase in carbon dioxide does not trigger an increase in breathing rate and depth. This confusion may be due to the fact that we often associate breathing with the exchange of oxygen and carbon dioxide, but in this case, the body's response is focused on regulating the levels of carbon dioxide rather than oxygen. Overall, the correct answer is A because it accurately describes the physiological response to high carbon dioxide levels in the body.