Biological Systems MCAT Practice Exam

Hyperventilation can lead to which of the following physiological conditions?

1. Respiratory alkalosis

2. Respiratory acidosis

3. Increased lung volume

4. Lower arterial oxygen tension

The correct answer is: Respiratory alkalosis

Hyperventilation involves an increased rate and depth of breathing, which results in the excessive expulsion of carbon dioxide (CO2) from the body. As CO2 is removed, the concentration of hydrogen ions in the blood decreases, leading to a condition known as respiratory alkalosis. In this state, the blood pH becomes elevated (more alkaline), which can disrupt normal cellular function and metabolic processes. The physiological effects of hyperventilation include this shift in acid-base balance due to the rapid loss of CO2. The body’s compensatory mechanisms may struggle to restore homeostasis, and symptoms such as dizziness, tingling in the extremities, and muscle cramps may arise. On the other hand, respiratory acidosis typically occurs when there is insufficient ventilation, leading to an accumulation of CO2, therefore decreasing the pH of the blood. Increased lung volume is generally associated with deep, slow breathing and does not directly relate to hyperventilation itself, as hyperventilation is characterized by rapid and shallow breaths. Lastly, lower arterial oxygen tension usually results from impaired lung function or hypoventilation, not hyperventilation, as hyperventilation typically enhances oxygen intake.