If the blood vessels in your body were stretched out in a line, they would go four times around the Earth.
It would also really hurt, we imagine.
There’s no question that the human body is an astonishing machine – but how much do you really know about the mass of meat and bones in which you walk around all day?
Where is the biggest bone in the human body? And where’s the smallest?
Our 15-question multiple-choice quiz will challenge your knowledge of the ins and outs of the human body, from your heart to your toes.
It starts off pretty easy with some basic trivia about the body, plus some clunkingly obvious fake "facts".
But stick with it, and it gets MUCH more challenging. Are you a master of the human body? Find out below!
Can’t get enough trivia action? Check out our dedicated Yahoo Quizzes page for more brainteasers! *