Brainlag PlusHow heart rate, breathing rate and breath volume change in exercise, working with the data, and oxygen debt.
Why everything speeds up
Working muscles respire faster, so they need more oxygen and glucose and make more carbon dioxide.
- Heart rate rises, so blood carries oxygen and glucose to the muscles faster and takes carbon dioxide away.
- Breathing rate and the volume of each breath rise, so more oxygen enters the blood and more carbon dioxide leaves.
volume breathed per minute = volume per breath × breaths per minute
cardiac output = stroke volume × heart rate
Cardiac output is on the Edexcel specification: learn it there. Stroke volume is the blood pumped by one beat, in cm³.
The rest of this lesson and its 11 practice questions are in Plus.
Screen 1 of 4, free to read.
- 11 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards