The brain uses over a quarter of the oxygen used by the human body. More human brain facts.
Your heart beats around 100000 times a day, 36500000 times a year and over a billion times if you live beyond 30. More human heart facts.
Red blood cells carry oxygen around the body. They are created inside the bone marrow of your bones. More blood facts.
The colour of a humans skin is determined by the level of pigment melanin that the body produces. Those with small amounts of melanin have light skin while those with large amounts have dark skin. More skin facts.
Adult lungs have a surface area of around 70 square metres! More lung facts.
Humans have a stage of sleep that features rapid eye movement (REM). REM sleep makes up around 25% of total sleep time and is often when you have your most vivid dreams. More eye facts.