Basic information | Respiratory tract | Lower respiratory system | Superlatives of the Lung

Superlatives of the lung

To give you some insight into what wonderful things the lungs are, we would like to quote you a few figures. Perhaps you would like to try and provide your own answers to the following questions before you see the real ones. You might be surprised how wide you were of the mark!

Q. If you joined up all the bronchi into a single tube, how long would it be?
A. Approximately 700 metres in length. This is the length of more than two Eiffel Towers.
 
Q. If you were to spread out all of the small and large breathing tubes, what total area would they cover?
A. Between 10 and 20 square metres.
 
Q. If you were to spread out all of the breathing tubes and all of the alveoli, what would the entire surface area be?
A. Between 60 and 90 square metres. This is about the area covered by a standard tennis court. This is large compared with the total area of the skin, which is about 1.7 square metres in the average adult, but not nearly as large as the total surface area of the mucus lining of the bowels which is so curled up inside that it would cover an area of between 200 and 400 square metres if flattened out.
 
Q. Approximately how many litres of air do we breathe in every day?
A. Between 10,000 and 15,000 litres. This is enough to fill a hot air balloon!
 
Q. How long does it take for the brushes or cilia lining the breathing tubes to remove an inhaled particle of dust?
A. Approximately 45 minutes.
 
Q. How many particles are there floating, on average, in each cubic metre of air that we breathe in which have to be captured and "swept out" again by the respiratory self-cleaning system?
A. Approximately 10,000 particles. In a room where people smoke, this number may rise to up to 100,000 floating particles per cubic metre of air, which creates much more work for the mucus lining membrane of the respiratory system.