Surprise! You have one more organ than you realized. As of November 2016, the mesentery is officially recognized as an organ in the human body. The announcement of the reclassification of this body part was published in The Lancet Gastroenterology & Hepatology. "In the paper, which has been peer reviewed and assessed, we are now saying we have an organ in the body which hasn't been acknowledged as such to date," said J Calvin Coffey, a researcher from the University Hospital Limerick in Ireland, who first discovered that the mesentery was an organ, as reported by ScienceAlert. "The anatomic description that had been laid down over 100 years of anatomy was incorrect. This organ is far from fragmented and complex. It is simply one continuous structure." But what does this organ that's been hiding out in our digestive system all this time actually do? Welp, we don't really know, but correctly identifying the mesentery as an organ is the first step in finding out.
A Model Of The Mesentery
Get to know your newest organ with this in-depth description.
What's Causing That Stitch in Your Side?
That cramp may be caused by an organ you've never heard of.
Key Facts In This Video
A stitch is known as a exercise related transient abdominal pain. 00:26
When exercising, you may become dehydrated, which means there is less fluid in between the layers of the peritoneum, resulting in pain. 01:37
Working out to strengthen your core should reduce movement in your abdomen while exercising. 02:02
People With Situs Inversus Have Flipped Organs
Your body really does know left from right!
Key Facts In This Video
On the outside, we look symmetrical, but that stops with our internal organs. Even organs that look symmetrical at first tip one way or the other -- the right lung is divided into three lobes while the left only has two, for instance. 00:12
We all have the same internal asymmetry, except for the 1 in 20,000 people who have a condition known as situs inversus, where the internal organs are inverted left to right. This usually causes no negative effects, except for rare emergency cases when it can keep doctors from identifying which organ is in pain. 01:11
Researchers looking at a special bunch of cells in a central region of an embryo found that its hair-like cilia began to beat in unison toward what would later become the left side. This beating washes a current over the outside of the embryo that activate pressure sensors, which turn on a gene that determines which side the embryo's organs will live on. 03:07
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