Inside the alveoli of our lungs, we have a special type of substance known as the pulmonary surfactant that consists of phospholipids and proteins. And what the pulmonary surfactant does is it decreases the surface tension of the fluid found inside the alveoli of our lungs. And that decreases the pressure that is needed to actually actually inflate those alveoli during the process of inhalation. So it decreases the pressure needed to expand or inflate the alveoli when we actually inhale, when we breathe in, it also prevents the alveoli from actually collapsing onto themselves when we actually exhale. So overall, what the surfactant in the alveoli of the lungs does is it makes the process of breathing much more efficient and much more easy to carry out. Now the question is why and how does the surfactant actually carry out these two functions?