Final answer:
The concentration of carbon dioxide in the blood stimulates the brain to produce respiration by triggering the respiratory centers and increasing the rate and depth of respiration. This helps remove carbon dioxide from the blood and reduce hydrogen ion levels.
Step-by-step explanation:
The major factor that stimulates the medulla oblongata and pons to produce respiration is the concentration of carbon dioxide in the blood, not oxygen concentration. As carbon dioxide levels increase, it readily diffuses across the blood-brain barrier and collects in the extracellular fluid, leading to increased levels of hydrogen ions and decreased pH. The increase in hydrogen ions triggers the respiratory centers in the brain to stimulate the contraction of respiratory muscles, increasing the rate and depth of respiration. This allows for the expulsion of carbon dioxide from the blood and brings more air into the lungs, promoting a reduction in carbon dioxide and hydrogen ion levels in the blood.