12 Facts About the Gallbladder


Don't feel too bad if you forgot you have a gallbladder—it's one of those body parts that people tend to ignore unless there's a problem. Here's a refresher: It's that small pouch beneath the liver whose primary function is to store bile, which helps you digest fats. So the next time you wolf down a Quarter Pounder with cheese, you can thank your gallbladder for doing its part. Here are a few other things you should know.


Right before you take your first bite of pizza, your gallbladder is full of bile—an alkaline fluid that's produced in the liver, transported to the gallbladder, and then released into the small intestine to help break down fat and bilirubin, a product of dead red blood cells. The organ can hold the equivalent of a shot glass of the yellow-green liquid, which causes it to swell up to the size of a small pear.

When you eat certain foods—especially fatty ones—the gallbladder releases the bile and deflates like a balloon. Although most gallbladders are roughly 1 inch wide and 3 inches long, there are notable exceptions. In 2017, a gallbladder removed from a woman in India measured nearly a foot long, making it the longest gallbladder in the world.


You don’t need your gallbladder to live a full and healthy life. Just ask British playwright Mark Ravenhill, who wrote an account for the BBC about getting his gallbladder removed after a gallstone—a solid object made of cholesterol or calcium salts and bilirubin—had moved painfully into his pancreas. "'The gallbladder's completely useless,'" Ravenhill recalled his doctor explaining. "'If it's going to be a problem, best just to take it out.'"

In addition to preventing more gallstones from forming, a physician may recommend that a patient’s gallbladder be removed due to other diseases, like cholecystitis (inflammation of the gallbladder) and cancer. In most cases, removing it doesn’t affect digestion, but there can be some complications. "People can certainly live without one, but they do have to watch their fat intake," says Ed Zuchelkowski, an anatomist and biology professor at California University of Pennsylvania. People who don't have gallbladders still produce bile, but it flows directly from the liver to the small intestine. The only difference is that "you would not have as much bile readily available to release," Zuchelkowski tells Mental Floss, which could cause minor problems like diarrhea if you're eating fatty foods.


"[The gallbladder] probably was more important to people in days when they would eat fewer meals and larger meals," Zuchelkowski says. This was generally the situation that our hunter-gatherer ancestors found themselves in. As Ravenhill notes, "feast or famine was the general rule." Nomadic groups ate large slabs of meat about once a week, and the gallbladder helped to quickly digest the onslaught of protein and fat.

Even though our diets and eating habits have changed drastically since then, evolution hasn't caught up—we still have the same digestive system. It's probably for this reason that "most meat-eating animals have a gallbladder," Zuchelkowski says. "Dogs do, cats do—they can concentrate bile just like we do, but I think you’d find that in animals that only eat vegetation, that’s where it’s likely to be missing.” However, Zuchelkowski notes that the gallbladder also helps you absorb fat-soluble vitamins like A, D, E, and K, so it still serves a useful function in people who are vegetarians.


A 2012 report from the Canadian Journal of Surgery recommended that astronauts consider having their appendix and gallbladder removed—even if their organs are perfectly healthy—to prevent appendicitis, gallstones, or cholecystitis from setting in when they’re far, far away from Earth's hospitals. “The ease and safety of surgical prophylaxis currently appears to outweigh the logistics of treating either acute appendicitis or cholecystitis during extended-duration space flight,” the authors wrote.


Alexander may have been great at conquering entire empires, but his organs weren’t exactly up to the task. The king of Macedonia died at the age of 34, and some historians believe that the cause was peritonitis (inflammation of the peritoneum, the tissue lining the abdomen), which itself was a result of acute cholecystitis. “Historians have suggested that the fatal biliary tract disease was fueled by excess consumption of alcohol and overeating at a banquet that Alexander threw for his leading officers in Babylon,” author Leah Hechtman writes in Clinical Naturopathic Medicine.


Gallbladder-related ailments have been afflicting humans for thousands of years, as evidenced by gallstones found in Egyptian mummies. And for thousands of years, people put up with it because they didn’t know what was wrong or how to fix it. In fact, it wasn’t until 1867 that the first cholecystotomy (removal of gallstones) was carried out. The surgery was performed by Dr. John S. Bobbs of Indianapolis, who had no idea what ailed his patient, 31-year-old Mary Wiggins, until he cut open a sac that he later realized was her gallbladder and “several solid bodies about the size of ordinary rifle bullets” fell out, according to The Indianapolis Star. Amazingly, Wiggins survived and lived to the age of 77. Fifteen years after this surgery, the first cholecystectomy (removal of the gallbladder) was performed in Germany.


Unlike the Guinness World Record for most Twinkies devoured in one sitting, this isn’t the kind of record you’d enjoy setting. In 1987, an 85-year-old woman complaining of severe abdominal pain showed up at Worthing Hospital in West Sussex, England, and doctors found a shockingly high number of gallstones—23,530, to be exact. In May 2018, a similar (albeit less severe) case of gallstones was reported in India, where a 43-year-old man underwent surgery to have thousands of them removed. “Usually we get to see two to 20 stones, but here there were so many and when we counted them, it was a whopping 4100,” the surgeon told Fox News.


Some practitioners of Eastern medicine—especially Traditional Chinese Medicine (TCM)—purport that gallbladder problems can cause certain kinds of headaches. TCM practitioners say our internal organs are connected to channels called meridians, which direct several fundamental substances—like blood, other bodily fluids, and qi (vital life energy)—throughout the body. The gallbladder meridian, for instance, runs along the side of the head near the temple. Through the practice of acupuncture, tiny needles are inserted into the skin along the gallbladder meridian in an effort to relieve tension and free up blocked qi. (Western scientists tend to disagree on what, if any, benefit acupuncture offers.)


Speaking of China, the country's primary language, Mandarin, hints at a link between organ function and personality. For instance, a word that’s assigned to bold and daring people translates to “big gallbladder,” and brave people are said to have “gallbladder strength,” according to The Conceptual Structure of Emotional Experience in Chinese. The word for coward, on the other hand, translates to “gallbladder small like mouse.” (Interestingly, mice do in fact have gallbladders, but rats don’t.)


You may remember learning something about the four humors during a high school lesson on ancient Greece. The theory, originating with Hippocrates, held that a person’s temperament was influenced by one of four bodily fluids: black bile, yellow bile, phlegm, and blood. Yellow bile, stored in the gallbladder, was said to make people choleric, or irritable. Disease was blamed on an imbalance of these four humors, and this remained a popular theory up until the 18th century. Because of this theory's longstanding influence, the word gall—a synonym for bile—also meant “embittered spirit” during medieval times. It wasn’t until 1882 that the word took on the meaning of "impudence" or "boldness" in American English—as in “I can’t believe he had the gall to finish that Netflix series without me.”


Well, not human gallbladders. Ancient Etruscans, a group of people who once lived in present-day Tuscany and whose civilization became part of the Roman empire, practiced a type of divination called haruspicy. The soothsayers were called haruspices (literally “gut gazers”), and they looked for clues from the gods in the markings, coloring, and shape of a sacrificial sheep’s liver and gallbladder. This was often done before the Romans went into battle, but the practice was never adopted as part of the state religion.


A crease called a "Phrygian cap" at the base of the gallbladder occurs in about 4 percent of people. Its odd name is something of a misnomer. It comes from its resemblance to a type of peaked felt hat called a pileus, worn by emancipated slaves in ancient Rome; the design was similar to the peaked caps then worn in Phrygia, a region in modern-day Turkey. Much later, during the French Revolution, people took to wearing Phrygian caps—which they likely confused with the pileus's style—as symbols of their freedom from tyranny. In the 20th century, the Smurfs started wearing them.

As for the aforementioned gallbladder abnormality, there’s no deeper symbolism in its name. The way it folds over just looks a lot like a Phrygian cap. Despite being a “congenital anomaly,” as a 2013 study published in Case Reports in Gastroenterology puts it, the condition typically causes no symptoms or complications.

‘Water’ in Kansas City Woman’s Ear Turned Out to Be a Venomous Brown Recluse Spider

N-sky/iStock via Getty Images
N-sky/iStock via Getty Images

Susie Torres, a resident of Kansas City, Missouri, woke up on Tuesday morning with the distinct feeling that water was lodged in her left ear. She likened it to the swooshing sensation that can often happen after swimming, WDAF-TV reports.

Instead of waiting for the problem to resolve itself, Torres went to the doctor—a decision that might have saved her from some serious pain. The medical assistant was the first to realize something was alarmingly amiss, and immediately called for backup.

“She ran out and said ‘I’m going to get a couple more people,’” Torres told 41 Action News. “She then said, ‘I think you have an insect in there.’” For many people, the thought of having any live insect stuck in an ear would be enough to cue a small- or large-scale freak-out, but Torres stayed calm.

The doctors “had a few tools and worked their magic and got it out,” Torres said. The “it” in question turned out to be a spider—and not just any harmless house spider (which you shouldn’t kill, by the way). It was a venomous brown recluse spider.

“Gross,” Torres told WDAF-TV. “Why, where, what, and how.”

Miraculously, the spider didn’t bite Torres. If it had, she would’ve ended up visiting the doctor with more than general ear discomfort: Brown recluse bites can cause pain, burning, fever, nausea, and purple or blue discoloration of the surrounding skin, according to Healthline.

Torres may have remained admirably level-headed throughout the ordeal, but that doesn’t mean she’s taking it lightly. “I went and put some cotton balls in my ears last night,” she told WDAF-TV. “I’m shaking off my clothes, and I don’t put my purse on the floor. I’m a little more cautious.”

Is this the first time an insect has posted up in the ear of an unsuspecting, innocent human? Absolutely not—here are six more horror stories, featuring a cockroach, a bed bug, and more.

[h/t WDAF-TV]

12 Fantastic Facts About the Immune System

monkeybusinessimages/iStock via Getty Images
monkeybusinessimages/iStock via Getty Images

If it weren't for our immune system, none of us would live very long. Not only does the immune system protect us from external pathogens like viruses, bacteria, and parasites, but it also battles cells that have mutated due to illnesses, like cancer, within the body. Here are 12 fascinating facts about the immune system.

1. The immune system saves lives.

The immune system is a complex network of tissues and organs that spreads throughout the entire body. In a nutshell, it works like this: A series of "sensors" within the system detects an intruding pathogen, like bacteria or a virus. Then the sensors signal other parts of the system to kill the pathogen and eliminate the infection.

"The immune system is being bombarded by all sorts of microbes all the time," Russell Vance, professor of immunology at University of California, Berkeley and an investigator for the Howard Hughes Medical Institute, tells Mental Floss. "Yet, even though we're not aware of it, it's saving our lives every day, and doing a remarkably good job of it."

2. Before scientists understood the immune system, illness was chalked up to unbalanced humors.

Long before physicians realized how invisible pathogens interacted with the body's system for fighting them off, doctors diagnosed all ills of the body and the mind according to the balance of "four humors": melancholic, phlegmatic, choleric, or sanguine. These criteria, devised by the Greek philosopher Hippocrates, were divided between the four elements, which were linked to bodily fluids (a.k.a. humors): earth (black bile), air (blood), water (phlegm) and fire (yellow bile), which also carried properties of cold, hot, moist, or dry. Through a combination of guesswork and observation, physicians would diagnose patients' humors and prescribe treatment that most likely did little to support the immune system's ability to resist infection.

3. Two men who unraveled the immune system's functions were bitter rivals.

Two scientists who discovered key functions of the immune system, Louis Pasteur and Robert Koch, should have been able to see their work as complementary, but they wound up rivals. Pasteur, a French microbiologist, was famous for his experiments demonstrating the mechanism of vaccines using weakened versions of the microbes. Koch, a German physician, established four essential conditions under which pathogenic bacteria can infect hosts, and used them to identify the Mycobacterium tuberculosis bacterium that causes tuberculosis. Though both helped establish the germ theory of disease—one of the foundations of modern medicine today—Pasteur and Koch's feud may have been aggravated by nationalism, a language barrier, criticisms of each other's work, and possibly a hint of jealousy.

4. Specialized blood cells are the immune system's greatest weapon.

The most powerful weapons in your immune system's arsenal are white blood cells, divided into two main types: lymphocytes, which create antigens for specific pathogens and kill them or escort them out of the body; and phagocytes, which ingest harmful bacteria. White blood cells not only attack foreign pathogens, but recognize these interlopers the next time they meet them and respond more quickly. Many of these immune cells are produced in your bone marrow but also in the spleen, lymph nodes, and thymus, and are stored in some of these tissues and other areas of the body. In the lymph nodes, which are located throughout your body but most noticeably in your armpits, throat, and groin, lymphatic fluid containing white blood cells flows through vein-like tubules to escort foreign invaders out.

5. The spleen helps your immune system work.

Though you can live without the spleen, an organ that lies between stomach and diaphragm, it's better to hang onto it for your immune function. According to Adriana Medina, a doctor who specializes in hematology and oncology at the Alvin and Lois Lapidus Cancer Institute at Sinai Hospital in Baltimore, your spleen is "one big lymph node" that makes new white blood cells and cleans out old blood cells from the body.

It's also a place where immune cells congregate. "Because the immune cells are spread out through the body," Vance says, "eventually they need to communicate with each other." They do so in both the spleen and lymph nodes.

6. You have immune cells in all of your tissues.

While immune cells may congregate more in lymph nodes than elsewhere, "every tissue in your body has immune cells stationed in it or circulating through it, constantly roving for signs of attack," Vance explains. These cells also circulate through the blood. The reason for their widespread presence is that there are thousands of different pathogens that might infect us, from bacteria to viruses to parasites. "To eliminate each of those different kinds of threats requires specialized detectors," he says.

7. How friendly you're feeling could be linked to your immune system.

From an evolutionary perspective, humans' high sociability may have less to do with our bigger brains, and more to do with our immune system's exposure to a greater number of bacteria and other pathogens.

Researchers at the University of Virginia School of Medicine have theorized that interferon gamma (IG), a substance that helps the immune system fight invaders, was linked to social behavior, which is one of the ways we become exposed to pathogens.

In mice, they found IG acted as a kind of brake to the brain's prefrontal cortex, essentially stopping aberrant hyperactivity that can cause negative changes in social behavior. When they blocked the IG molecule, the mice's prefrontal cortexes became hyperactive, resulting in less sociability. When they restored the function, the mice's brains returned to normal, as did their social behavior.

8. Your immune system might recruit unlikely organs, like the appendix, into service.

The appendix gets a bad rap as a vestigial organ that does nothing but occasionally go septic and create a need for immediate surgery. But the appendix may help keep your gut in good shape. According to Gabrielle Belz, professor of molecular immunology at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia, research by Duke University's Randal Bollinger and Bill Parker suggests the appendix houses symbiotic bacteria that are important for overall gut health—especially after infections wipe out the gut's good microbes. Special immune cells known as innate lymphoid cells (ILCs) in the appendix may help to repopulate the gut with healthy bacteria and put the gut back on track to recovery.

9. Gut bacteria has been shown to boost immune systems in mice.

Researchers at the University of Chicago noticed that one group of mice in their lab had a stronger response to a cancer treatment than other mice. They eventually traced the reason to a strain of bacteria—Bifidobacterium—in the mice's guts that boosted the animals' immune system to such a degree they could compare it to anti-cancer drugs called checkpoint inhibitors, which keep the immune system from overreacting.

To test their theory, they transferred fecal matter from the robust mice to the stomachs of less immune-strengthened mice, with positive results: The treated mice mounted stronger immune responses and tumor growth slowed. When they compared the bacterial transfer effects with the effects of a checkpoint inhibitor drug, they found that the bacteria treatment was just as effective. The researchers believe that, with further study, the same effect could be seen in human cancer patients.

10. Scientists are trying to harness the immune system's "Pac-Man" cells to treat cancer.

Aggressive pediatric tumors are difficult to treat due to the toxicity of chemotherapy, but some researchers are hoping to develop effective treatments without the harmful side effects. Stanford researchers designed a study around a recently discovered molecule known as CD47, a protein expressed on the surface of all cells, and how it interacts with macrophages, white blood cells that kill abnormal cells. "Think of the macrophages as the Pac-Man of the immune system," Samuel Cheshier, lead study author and assistant professor of neurosurgery at Stanford Medicine, tells Mental Floss.

CD47 sends the immune system's macrophages a "don't eat me" signal. Cancer cells fool the immune system into not destroying them by secreting high amounts of CD47. When Cheshier and his team blocked the CD47 signals on cancer cells, the macrophages could identify the cancer cells and eat them, without toxic side effects to healthy cells. The treatment successfully shrank all five of the common pediatric tumors, without the nasty side effects of chemotherapy.

11. A new therapy for type 1 diabetes tricks the immune system.

In those with type 1 diabetes, the body attacks its own pancreatic cells, interrupting its normal ability to produce insulin in response to glucose. In a 2016 paper, researchers at MIT, in collaboration with Boston's Children's Hospital, successfully designed a new material that allows them to encapsulate and transplant healthy pancreatic "islet" cells into diabetic mice without triggering an immune response. Made from seaweed, the substance is benign enough that the body doesn't react to it, and porous enough to allow the islet cells to be placed in the abdomen of mice, where they restore the pancreatic function. Senior author Daniel Anderson, an associate professor at MIT, said in a statement that this approach "has the potential to provide [human] diabetics with a new pancreas that is protected from the immune system, which would allow them to control their blood sugar without taking drugs. That's the dream."

12. Immunotherapy is on the cutting edge of immune system research.

Over the last few years, research in the field of immunology has focused on developing cancer treatments using immunotherapy. This method engineers the patient's own normal cells to attack the cancer cells. Vance says the technique could be used for many more conditions. "I feel like that could be just the tip of the iceberg," he says. "If we can understand better what the cancer and immunotherapy is showing, maybe we can go in there and manipulate the immune responses and get good outcomes for other diseases, too."