Kaplan Nursing Entrance Practice Exam

What feature of the medulla oblongata contributes to respiratory control?

1. Regulates blood pressure

2. Monitors carbon dioxide content

3. Stimulates vocal cords

4. Controls digestive processes

The correct answer is: Monitors carbon dioxide content

The correct answer highlights a critical function of the medulla oblongata in maintaining homeostasis in the body, particularly regarding respiration. The medulla oblongata contains chemoreceptors that are sensitive to changes in the levels of carbon dioxide (CO2) in the blood. When carbon dioxide levels rise, it leads to a corresponding increase in acidosis (a decrease in pH), stimulating the respiratory centers in the medulla. This triggers an increase in the rate and depth of breathing, enhancing the expulsion of carbon dioxide and helping to restore normal pH balance. This feature is essential as it directly influences the respiratory rate, ensuring that the body's metabolic needs are met by adjusting the respiratory process according to the levels of carbon dioxide present. Maintaining appropriate CO2 levels is vital since elevated levels can lead to respiratory acidosis, which can have serious implications for the body’s function. The other options, while they represent important processes in the body, do not relate primarily to the respiratory control aspect of the medulla oblongata. For instance, while the regulation of blood pressure is a significant function of the medulla, it does not play a direct role in regulating breathing. Similarly, the stimulation of vocal cords pertains to laryngeal function and