An increase in the level of carbon dioxide in the blood will:Question 10Select one:a.decrease the rate of breathing.b.increase the rate of breathing.c.decrease pulmonary ventilation.d.decrease the alveolar ventilation re.increase the pH of arterial blood.

To answer the question about the effect of an increase in the level of carbon dioxide in the blood, let's break it down step by step:

1. Understanding Carbon Dioxide's Role: Carbon dioxide (CO₂) is a byproduct of cellular respiration and is transported in the blood to be exhaled by the lungs. High levels of CO₂ in the blood can lead to a condition called hypercapnia.

2. Body's Response to Increased CO₂: The body has chemoreceptors that detect the levels of CO₂ in the blood. When CO₂ levels rise, these chemoreceptors send signals to the respiratory center in the brain.

3. Respiratory Center's Reaction: The respiratory center in the brain responds to high CO₂ levels by increasing the rate and depth of breathing. This is a compensatory mechanism to expel more CO₂ from the body and bring the levels back to normal.

4. Effect on Breathing Rate: Given the body's response to high CO₂ levels, the rate of breathing will increase to help remove the excess CO₂.

5. Other Options:

   • Decreasing the rate of breathing (option a) would worsen the situation by allowing CO₂ levels to rise further.
   • Decreasing pulmonary ventilation (option c) and alveolar ventilation (option d) would also lead to higher CO₂ levels.
   • Increasing the pH of arterial blood (option e) is incorrect because high CO₂ levels actually lower the pH, making the blood more acidic.

Based on this analysis, the correct answer is:

b. increase the rate of breathing.