We may just look like hair and skin from the outside, but the human body is a magnificent creature made up of millions of parts.
From atoms, to DNA to the amount of iron naturally found in adults, it's easy to forget how much it takes to make up one human body. In the video above by Alltime Numbers, we learn incredibly cool facts like the human heart beats (on average) 100,000 times a day and how we make over 28,000 litres of saliva over our lifetime — that's a lot of spit!
And as adults, unless we're working in a biological field, the last time most of us were taught about the human body's wonderful makeup was probably in elementary or high school. This video is a great way to refresh yourself, but also show off some newly learned factoids.
Watch the video above to see what we're talking about.
Also on HuffPost
