
Keeping those lungs open…
Your lungs are made up of millions grape-like structures called alveoli, which are the main exchange sites for oxygen getting into your blood when you take a breath in, and carbon dioxide getting out when you exhale.
The alveoli are predominantly made up of two cells: Alveolar cells types I and II. Type II cells produce an organic amphiphilic compound called surfactant, which lines your alveoli to decrease surface tension and prevent them from collapsing. Research is showing that COVID-19 tends to target the ACE-2 receptors on type II alveolar cells, which leads to insufficient surfactant, increased surface tension, and subsequent collapse of the alveoli. With less open alveoli, the body has less sites for oxygen and carbon dioxide exchange, and this is why shortness of breath is a frequent symptom. For more information on the pathophysiology of COVID-19, check out our educational resources on the COVID-19 Operation page (the “Ninja Nerd” video has a particularly good explanation).