A closer look
The only reason your heart is on the left side of your chest is because of millions of microscopic, spinning biological windshield wipers. During early embryonic development, tiny hair-like structures called cilia tilt and rotate in a very specific direction to generate a localized fluid current. This ciliary flow acts like a biological lazy river, sweeping specific morphogen proteins to one side of the embryo, firmly dictating exactly where your asymmetric internal organs will grow.
