The Respiratory System

During the previous post about the greenhouse effect, we were trying to put CO2 in the jar. This made me curious about the respiratory system. In today's blog post, we are going to cover all the things I learned about it.

In the following table, you can see the percentage of gases in the atmosphere and how these percentages change if we re-breathe the same air. As we breathe in, the oxygen depletes and gets transformed into carbon dioxide. So, by breathing in and out using a balloon I managed to increase the percentage of carbon dioxide to do my greenhouse experiment. This is a process that is not healthy and you're not supposed to do it, but a one-shot for the experiment was okay. In fact, this is exactly what happened to astronauts aboard Apollo 13 mission to the Moon in 1970.

Notice also how our body totally ignores the nitrogen.

I also learned how breathing happens by using a muscle called the diaphragm, which contracts to create more volume inside our chest. This lowers pressure and forces air from the outside to come into the lungs. To demonstrate how this process works I built a model of our respiratory system with a plastic bottle and two balloons. The balloon at the top represents our mouth and one lung, and the balloon at the bottom simulates the diaphragm. As you can see in the following video, as the diaphragm contracts and pulls down creates low pressure and the air from the outside comes in and inflates the lung. 

If you live up to 80 years, your diaphragm will contract and relax up to around 700 million times, and it doesn't even get paid for it.

I also looked up a science book and learnt about the different parts of our respiratory system, including the trachea, bronchioles, and the alveoli, which is where the actual gas exchange happens. A cool fact is that we have 480 million alveoli, which have a combined area of 80 square meters, which is equivalent to a tennis court.

Then I realized that in my collection of microscope slides I had a slide with a section of a lung. I checked it under the microscope. Here you have a photo of my microscope slide. You can appreciate the alveoli and a blood vesel that has been cut length-wise, which is why it looks elongated

In this other shot you can see an artery at the top and a bronchiole at the bottom. Both have been cut transversaly and that's why we see them like circles. The pink dots inside the artery are red blood cells.

Do you have any other cool facts about our respiratory system?