AEMCA Practice Exam

What does the Bohr effect describe?

1. The influence of oxygen on hemoglobin

2. The effect of temperature on blood pressure

3. The relationship between carbon dioxide and hemoglobin affinity for oxygen

4. The impact of blood volume on heart rate

The correct answer is: The relationship between carbon dioxide and hemoglobin affinity for oxygen

The Bohr effect specifically describes how an increase in carbon dioxide concentration and a decrease in pH (which often occurs in more metabolically active tissues) lead to a decrease in the affinity of hemoglobin for oxygen. This physiological phenomenon is crucial because it facilitates the efficient release of oxygen in tissues that are actively consuming it, such as muscles during exercise. When carbon dioxide levels rise, it causes a shift in the hemoglobin-oxygen dissociation curve, promoting the release of oxygen where it is most needed. The other options, while related to the overall topic of respiratory physiology or cardiovascular function, do not accurately define the Bohr effect. The influence of oxygen on hemoglobin is more closely related to the oxygen saturation of hemoglobin itself rather than the response to carbon dioxide. The effect of temperature on blood pressure does not pertain to the Bohr effect but instead relates to cardiovascular physiology. Similarly, the impact of blood volume on heart rate does not connect with the interaction between carbon dioxide and hemoglobin in the way the Bohr effect does. The emphasis of the Bohr effect is uniquely on the interplay between carbon dioxide levels and hemoglobin's oxygen-binding capacity.