You know, it’s funny. Every now and then, something pops up in the medical world that makes even us doctors pause and say, “Huh, well look at that.” Recently, a patient came in, a bit wide-eyed, holding a printout from the internet. “Doc,” he said, “is it true? Did we just… find a new organ?” He was talking about the mesentery. And in a way, he was right! It’s not new new, like we just stumbled upon it, but our understanding of it has taken a giant leap.
For the longest time, we thought of the mesentery as just a series of separate bits of tissue, like little anchors holding your intestines to the back wall of your tummy. But in 2016, researchers really looked closely and said, “Wait a minute.” They showed that the mesentery is actually one continuous, distinct organ. An organ! Just like your heart or your liver. It’s a pretty big deal, and it’s changing how we look at a lot of things inside our abdomen.
So, What Exactly is This Mesentery?
Imagine a fan, a folded one. That’s a bit like the mesentery. It’s a broad, fan-shaped fold of tissue that starts at the back of your abdomen and attaches to your intestines, holding them in place. It’s part of what we call the peritoneum, which is a thin membrane, like a lining, that covers your abdominal cavity and the organs within it.
It’s a bit of a “back to the future” story, really. If you look at old drawings from hundreds of years ago, even from Leonardo da Vinci, they drew the mesentery as one single structure. Then, for a long while, the thinking shifted, and textbooks described it as fragmented. Now, science has brought us full circle. It’s one organ, doing a whole lot more than just holding things up.
What Does the Mesentery Do for You?
It turns out, this organ is quite the multitasker. We’re still learning all its secrets, but here’s what we know it’s busy doing:
- Keeping things in place: This is its most obvious job. Your mesentery anchors parts of your intestines to your abdominal wall and helps suspend other parts. Without it, your intestines could get all jumbled up, or worse, twisted. Imagine trying to digest your food if everything was in a knot! Some even think its structure is what allows us humans to walk upright.
- Nourishing your digestive organs: The mesentery is like a lifeline. It contains the blood vessels, nerves, and lymph nodes (little glands that are part of your immune system) that supply your intestines. It’s there from the very beginning, even before other digestive organs fully form in a developing baby. Organs like your liver, spleen, pancreas, and intestines actually develop within the mesentery.
- A communication hub: Because it connects everything, it acts like a signaling platform. Those shared nerves and blood vessels allow your digestive organs to “talk” to each other and work as a coordinated system. For example, the lymph nodes in the mesentery are on high alert, trapping germs like viruses and bacteria from your intestines. It even makes something called C-reactive protein (CRP), a substance that helps manage inflammation, which is your body’s natural healing response.
Understanding the Mesentery’s Anatomy
Let’s get a bit more specific about this fascinating structure.
Where is it Hiding?
The mesentery starts deep inside, at the back of your abdominal cavity, near your lower back. It originates around a major blood vessel called the superior mesenteric artery, which is a key supplier of blood to your pancreas and intestines. From there, it extends out, kind of like a spiral, reaching all the way from your small intestine down to your rectum.
What’s its Structure Like?
It’s one continuous organ, but different parts of it have different names based on what they’re attached to:
- Small-intestinal mesentery: Connects to your small intestine.
- Right mesocolon: Attaches the right side of your large intestine (colon) to the back wall of your abdomen.
- Transverse mesocolon: Runs across the part of your colon that goes horizontally across your belly.
- Left mesocolon: Secures the left side of your large intestine to the back abdominal wall.
- Mesosigmoid: Connects a part of your sigmoid colon (the S-shaped bit before your rectum) to the back wall.
- Mesorectum: The bottom part, attached to your rectum.
Realizing it’s all connected, especially those right and left mesocolon parts which weren’t always seen as part of the main mesentery, is a big shift. It helps us understand how organs develop and can even make surgeries a bit more straightforward.
How Big Are We Talking?
If you could lay an adult mesentery out flat, it would be about 6 feet long! Of course, it’s all neatly folded and arranged inside you.
What’s it Made Of?
Mostly, it’s made of adipose tissue – that’s the medical term for body fat. Yes, a lot of that “belly fat” or “gut” people talk about is actually your mesentery! It also has connective tissue holding that fat in place. The whole thing is wrapped in a protective cell layer called the mesothelium. And another layer of connective tissue, Toldt’s fascia, helps bind it to your abdominal wall. Plus, as I mentioned, it’s packed with those important lymph nodes.
When the Mesentery Faces Problems
Because the mesentery is so central to your digestive system, it can be involved in various health issues. We’re learning more all the time.
- Crohn’s disease: This is a type of inflammatory bowel disease (IBD). New research suggests the mesentery plays a big role in how Crohn’s progresses. Some even wonder if Crohn’s might start in the mesentery. It’s an active area of study.
- Excess Visceral Fat: Remember that adipose tissue? While some fat is normal and protective, too much visceral fat (the deep belly fat that makes up the mesentery) isn’t great. It increases your risk for:
- Diabetes
- High blood pressure (hypertension)
- Obesity
- Coronary artery disease
- Metabolic syndrome
- Stroke
- Cancer: Sometimes cancer can start in the mesentery itself, or cancer cells from other abdominal organs can spread there.
- Infections: Those lymph nodes are great at fighting germs, but sometimes germs can hide out in them and cause problems later.
- Sclerosing mesenteritis and Mesenteric panniculitis: These are conditions where there’s too much inflammation in the mesentery. Sclerosing mesenteritis can cause scarring and block blood vessels, which is serious. Mesenteric panniculitis is usually less severe.
- Hernias: This is when an organ or tissue pushes through a weak spot. Mesenteric hernias can happen due to issues present at birth or as a complication after abdominal surgery.
- Malrotation: This is when a baby’s intestines don’t form or coil correctly during development. Since the mesentery guides this, it’s involved. Surgery is needed to fix it.
- Volvulus: This is a dangerous twisting of the intestine and its mesentery, often because the mesentery isn’t attached securely. It can cut off blood supply and is an emergency.
It’s pretty clear that if something affects a digestive organ, the mesentery is likely involved too. This new understanding is opening doors for better treatments. For instance, sometimes removing parts of the mesentery during surgery for Crohn’s or colon cancer can improve outcomes. And knowing it’s one continuous structure can simplify how surgeons approach operations in the abdomen.
Taking Care of Your Mesentery
So, how can you look after this important, if somewhat newly appreciated, organ? A lot of it comes down to managing that visceral fat. Here are some things we often talk about in the clinic:
- Watch what you eat: Try to limit trans fats, too much sugar (especially from things like soda and candy), excessive salt, and highly processed foods. Going easy on fried foods and alcohol helps too.
- Get moving: Regular exercise is key. We usually recommend at least 150 minutes of moderate-intensity activity each week.
- Prioritize sleep: Believe it or not, not getting enough good quality sleep can lead to more visceral fat. Aim for around eight hours if you can.
- Manage stress: Chronic stress can cause your body to release more cortisol, a hormone that can contribute to belly fat. Finding healthy ways to cope with stress is good for your whole body, mesentery included!
Your Mesentery: Key Takeaways
This is a lot to take in, I know! Here are the main things to remember about your amazing mesentery:
- The mesentery is now officially recognized as a single, continuous organ in your abdomen.
- It acts like an anchor, holding your intestines in place and supporting them.
- It’s crucial for supplying blood, nerves, and immune support (via lymph nodes) to your digestive organs.
- The mesentery is primarily made of adipose tissue (visceral fat), and too much can be linked to health problems like diabetes and heart disease.
- Understanding the mesentery is changing how we think about digestive diseases like Crohn’s and even surgical approaches.
- You can help care for your mesentery by maintaining a healthy lifestyle: balanced diet, regular exercise, good sleep, and stress management.
It’s a fascinating part of us, isn’t it? Just goes to show, there’s always more to learn about the incredible human body. You’re not alone in figuring this all out.
