Did you know that it’s entirely possible for people to live comfortable, healthy lives with their organs on the opposite sides of their bodies? This condition, known as situs inversus, does not cause bodily harm in most cases, and many people with situs inversus don’t even know they have it. If this is the case, then why do our organs have to be arranged the way that they are? Why does the heart have to be on the left while the liver is on the right?

A recent scientific study discovered that the side on which each of your organs end up is determined by the movement of hair-like cilia while you’re still an embryo! During embryonic development, the cilia start to move in unison, and the cells whose cilia move to the left end up in organs on the left side of your body, while those that rotate to the right become the organs that fill the right side of your body. So people with situs inversus simply have cilia that move in opposite directions from the rest of the population.

Watch the video below to learn more about situs inversus and how your organs are arranged.

Featured photo credit: public domain via photos-public-domain.com