Meet the newest organ in the human body - the mesentery.
The mesentery is part of our digestive system and we've known about it for a long time - but until now it was believed to be lots of separate bits of our stomach, but recent research has shown that it's actually one, continuous organ.
It's part of the the lining of our abdominal cavity and attaches our intestines to the wall of our abdomen, to keep all our digestive system locked in place.
Weirdly though, no-one knows yet exactly what its purpose is.
How many organs does a human have?
Many people think humans have just five organs: the heart, the liver, the brain, the lungs and the kidneys.
They are known as the "vital" organs.
In fact the human body has 79 - including the mesentery.
Do you know what your largest organ is? It's your skin and it keeps out potentially harmful viruses, bacteria and germs.