National Dental Examining Board of Canada (NDEB) Practice Exam

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Master your National Dental Examining Board of Canada (NDEB) exams with our comprehensive practice guide. Achieve excellence in your dental certification with expertly crafted questions and detailed explanations.

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

The strongest stimulus to respiration is...

Increase in arterial carbon dioxide
Decrease in arterial oxygen
Decrease in blood pressure
Increase in blood sugar levels

The correct answer is: Increase in arterial carbon dioxide

Carbon dioxide is the main stimulus to breathe because it is produced by our cells as they use oxygen. As carbon dioxide builds up in our blood, it causes a decrease in blood pH, which is detected by chemoreceptors in our brain. This triggers our brain to send signals to our respiratory muscles to increase our breathing rate and depth, in order to remove the excess carbon dioxide from our body. None of the other options have the same effect on our respiratory system. A decrease in arterial oxygen levels and an increase in blood sugar levels do not directly stimulate our breathing, although they can indirectly affect it. A decrease in blood pressure may trigger an increase in respiratory rate, but it is not considered the strongest stimulus. Therefore, the strongest stimulus to respiration is an increase in arterial carbon dioxide levels.