Watch the video above for 13 things you might not have known about human cells. If you’re not quite sure what some of the facts are, or how it works, we explain it all below.

A cell is the smallest structural and functional unit of an organism, and the human body comprises of about 100 trillion cells: more than 30 times the stars in the known galaxy. While every minute more than 200 million cells die in the human body, the body created billions more every day. Essentially this means that every ten years your body will have completely changed.

It takes a only 60 seconds for blood vessels to circulate through the body. Accumulated over ten years, a cell has the potential to travel over 96 000 kilometres. That is 2,4 times the circumference of Earth.

The longest cell in the body is the motor neuron. It measures 0,1 millimetres in diameter and about 1 metre in length. It is a nerve cell responsible for relaying impulses from the brain or spinal cord to a muscle or gland. This human cell is almost twice as long is the world’s shortest adult, Chandra Bahadur Dangi. Dangi is from Nepal and was declared the world’s shortest man by Guinness World Records as he measured 54,64 centimetres.

The largest cell in the human body is the female egg, at about 0,12 millimetre in diameter and it is visible to the naked eye. The size is comparable to a full-stop (yes, like this: .), or the end of a single strand of human hair. As a side note, an ovary is about 5 centimetres long. The sperm cell is the smallest human cell.

Human cells create copies of themselves by DNA replication. This is the process by which a double helix is unwound and each strand of human DNA becomes a template for the next. But as we grow older the replication cycle does become damaged.

Here are some other facts you might not have known: Laughing helps keeps cells healthy, while sexual activity increases immune globulin that protects the body against diseases.

Source, video credit: Cell Health Institute