12 Intriguing Facts About the Intestines

When we talk about the belly, gut, or bowels, what we're really talking about are the intestines—long, hollow, coiled tubes that comprise a major part of the digestive tract, running from the stomach to the anus. The intestines begin with the small intestine, divided into three parts whimsically named the duodenum, jejunum, and ileum, which absorb most of the nutrients from what we eat and drink. Food then moves into the large intestine, or colon, which absorbs water from the digested food and expels it into the rectum. That's when sensitive nerves in your rectum create the sensation of needing to poop.

These organs can be the source of intestinal pain, such as in irritable bowel syndrome, but they can also support microbes that are beneficial to your overall health. Here are some more facts about your intestines.

1. The intestines were named by medieval anatomists.

Medieval anatomists had a pretty good understanding of the physiology of the gut, and are the ones who gave the intestinal sections their names, which are still used today in modern anatomy. When they weren't moralizing about the organs, they got metaphorical about them. In 1535, the Spanish doctor Andrés Laguna noted that because the intestines "carry the chyle and all the excrement through the entire region of the stomach as if through the Ocean Sea," they could be likened to "those tall ships which as soon as they have crossed the ocean come to Rouen with their cargoes on their way to Paris but transfer their cargoes at Rouen into small boats for the last stage of the journey up the Seine."

2. Leonardo da Vinci believed the intestines helped you breathe.

Leonardo mistakenly believed the digestive system aided respiratory function. In 1490, he wrote in his unpublished notebooks, "The compressed intestines with the condensed air which is generated in them, thrust the diaphragm upwards; the diaphragm compresses the lungs and expresses the air." While that isn't anatomically accurate, it is true that the opening of the lungs is helped by the relaxation of stomach muscles, which does draw down the diaphragm.

3. Your intestines could cover two tennis courts ...

Your intestines take up a whole lot of square footage inside you. "The surface area of the intestines, if laid out flat, would cover two tennis courts," Colby Zaph, a professor of immunology in the department of biochemistry and molecular biology at Melbourne's Monash University, tells Mental Floss. The small intestine alone is about 20 feet long, and the large intestine about 5 feet long.

4. ... and they're pretty athletic.

The process of moving food through your intestines requires a wave-like pattern of muscular action, known as peristalsis, which you can see in action during surgery in this YouTube video.

5. Your intestines can fold like a telescope—but that's not something you want to happen.

Intussusception is the name of a condition where a part of your intestine folds in on itself, usually between the lower part of the small intestine and the beginning of the large intestine. It often presents as severe intestinal pain and requires immediate medical attention. It's very rare, and in children may be related to a viral infection. In adults, it's more commonly a symptom of an abnormal growth or polyp.

6. Intestines are very discriminating.

"The intestines have to discriminate between good things—food, water, vitamins, good bacteria—and bad things, such as infectious organisms like viruses, parasites and bad bacteria," Zaph says. Researchers don't entirely know how the intestines do this. Zaph says that while your intestines are designed to keep dangerous bacteria contained, infectious microbes can sometimes penetrate your immune system through your intestines.

7. The small intestine is covered in "fingers" ...

The lining of the small intestine is blanketed in tiny finger-like protrusions known as villi. These villi are then covered in even tinier protrusions called microvilli, which help capture food particles to absorb nutrients, and move food on to the large intestine.

8. ... And you can't live without it.

Your small intestine "is the sole point of food and water absorption," Zaph says. Without it, "you'd have to be fed through the blood."

9. The intestines house your microbiome. 

The microbiome is made up of all kinds of microorganisms, including bacteria, viruses, fungi, and protozoans, "and probably used to include worm parasites too," says Zaph. So in a way, he adds, "we are constantly infected with something, but it [can be] helpful, not harmful."

10. Intestines are sensitive to change.

Zaph says that many factors change the composition of the microbiome, including antibiotics, foods we eat, stress, and infections. But in general, most people's microbiomes return to a stable state after these events. "The microbiome composition is different between people and affected by diseases. But we still don't know whether the different microbiomes cause disease, or are a result in the development of disease," he says.

11. Transferring bacteria from one gut to another can transfer disease—or maybe cure it.

"Studies in mice show that transplanting microbes from obese mice can transfer obesity to thin mice," Zaph says. But transplanting microbes from healthy people into sick people can be a powerful treatment for some intestinal infections, like that of the bacteria Clostridium difficile, he adds. Research is pouring out on how the microbiome affects various diseases, including multiple sclerosis, Parkinson's, and even autism.

12. The microbes in your intestines might influence how you respond to medical treatments.

Some people don't respond to cancer drugs as effectively as others, Zaph says. "One reason is that different microbiomes can metabolize the drugs differently." This has huge ramifications for chemotherapy and new cancer treatments called checkpoint inhibitors. As scientists learn more about how different bacteria metabolize drugs, they could possibly improve how effective existing cancer treatments are.

12 Creative Ways to Spend Your FSA Money Before the Deadline

stockfour/iStock via Getty Images
stockfour/iStock via Getty Images

If you have a Flexible Spending Account (FSA), chances are, time is running out for you to use that cash. Depending on your employer’s rules, if you don’t spend your FSA money by the end of the grace period, you potentially lose some of it. Lost cash is never a good thing.

For those unfamiliar, an FSA is an employer-sponsored spending account. You deposit pre-tax dollars into the account, and you can spend that money on a number of health care expenses. It’s kind of like a Health Savings Account (HSA), but with a few big differences—namely, your HSA funds roll over from year to year, so there’s no deadline to spend it all. With an FSA, though, most of your funds expire at the end of the year. Bummer.

The good news is: The law allows employers to roll $500 over into the new year and also offer a grace period of up to two and a half months to use that cash (March 15). Depending on your employer, you might not even have that long, though. The deadline is fast approaching for many account holders, so if you have to use your FSA money soon, here are a handful of creative ways to spend it.

1. Buy some new shades.

Head to the optometrist, get an eye prescription, then use your FSA funds to buy some new specs or shades. Contact lenses and solution are also covered.

You can also buy reading glasses with your FSA money, and you don’t even need a prescription.

2. Try acupuncture.

Scientists are divided on the efficacy of acupuncture, but some studies show it’s useful for treating chronic pain, arthritis, and even depression. If you’ve been curious about the treatment, now's a good time to try it: Your FSA money will cover acupuncture sessions in some cases. You can even buy an acupressure mat without a prescription.

If you’d rather go to a chiropractor, your FSA funds cover those visits, too.

3. Stock up on staples.

If you’re running low on standard over-the-counter meds, good news: Most of them are FSA-eligible. This includes headache medicine, pain relievers, antacids, heartburn meds, and anything else your heart (or other parts of your body) desires.

There’s one big caveat, though: Most of these require a prescription in order to be eligible, so you may have to make an appointment with your doctor first. The FSA store tells you which over-the-counter items require a prescription.

4. Treat your feet.

Give your feet a break with a pair of massaging gel shoe inserts. They’re FSA-eligible, along with a few other foot care products, including arch braces, toe cushions, and callus trimmers.

In some cases, foot massagers or circulators may be covered, too. For example, here’s one that’s available via the FSA store, no prescription necessary.

5. Get clear skin.

Yep—acne treatments, toner, and other skin care products are all eligible for FSA spending. Again, most of these require a prescription for reimbursement, but don’t let that deter you. Your doctor is familiar with the rules and you shouldn’t have trouble getting a prescription. And, as WageWorks points out, your prescription also lasts for a year. Check the rules of your FSA plan to see if you need a separate prescription for each item, or if you can include multiple products or drug categories on a single prescription.

While we’re on the topic of faces, lip balm is another great way to spend your FSA funds—and you don’t need a prescription for that. There’s also no prescription necessary for this vibrating face massager.

6. Fill your medicine cabinet.

If your medicine cabinet is getting bare, or you don’t have one to begin with, stock it with a handful of FSA-eligible items. Here are some items that don’t require a prescription:

You can also stock up on first aid kits. You don’t need a prescription to buy those, and many of them come with pain relievers and other medicine.

7. Make sure you’re covered in the bedroom.

Condoms are FSA-eligible, and so are pregnancy tests, monitors, and fertility kits. Female contraceptives are also covered when you have a prescription.

8. Prepare for your upcoming vacation.

If you have a vacation planned this year, use your FSA money to stock up on trip essentials. For example:

9. Get a better night’s sleep.

If you have trouble sleeping, sleep aids are eligible, though you’ll need a prescription. If you want to try a sleep mask, many of them are eligible without a prescription. For example, there’s this relaxing sleep mask and this thermal eye mask.

For those nights you’re sleeping off a cold or flu, a vaporizer can make a big difference, and those are eligible, too (no prescription required). Bed warmers like this one are often covered, too.

Your FSA funds likely cover more than you realize, so if you have to use them up by the deadline, get creative. This list should help you get started, and many drugstores will tell you which items are FSA-eligible when you shop online.

10. Go to the dentist.

While basics like toothpaste and cosmetic procedures like whitening treatments aren’t FSA eligible, most of the expenses you incur at your dentist’s office are. That includes co-pays and deductibles as well as fees for cleanings, x-rays, fillings, and even the cost of braces. There are also some products you can buy over-the-counter without ever visiting the dentist. Some mouthguards that prevent you from grinding your teeth at night are eligible, as are cleaning solutions for retainers and dentures.

11. Try some new gadgets.

If you still have some extra cash to burn, it’s a great time to try some expensive high-tech devices that you’ve been curious about but might not otherwise want to splurge on. The list includes light therapy treatments for acne, vibrating nausea relief bands, electrical stimulation devices for chronic pain, cloud-connected stethoscopes, and smart thermometers.

12. Head to Amazon.

There are plenty of FSA-eligible items available on Amazon, including items for foot health, cold and allergy medication, eye care, and first-aid kits. Find out more details on how to spend your FSA money on Amazon here.

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30 Pungent Facts About Farts

This man is clearly not trying to hide the fact he just passed gas.
This man is clearly not trying to hide the fact he just passed gas.
BrilliantEye/iStock via Getty Images

Whether you openly admit it or desperately try to hide it, it’s an undeniable fact that every living and breathing human being farts. And while passing what you thought was going to be silent gas only to be wrong in certain situations can definitely be embarrassing, there’s something undeniably humorous about flatulence—no matter your age.

If you do love a good fart joke, you’re in good company. The very first recorded joke, which was written by the Sumerians and dates all the way back to 1900 BCE, was about—you guessed it—breaking wind. And some of the world's great thinkers, from William Shakespeare to J.D. Salinger, have slipped a fart joke (or 10) into their work.

In this episode of The List Show, we're sniffing out 30 fascinating facts about farts—from why humans expel gas to how often the average adult squeezes the cheese. You can watch the full episode below.

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