60 Fun Facts About Stomach

Which organ, tucked behind the stomach, makes both insulin and digestive juices?

The pancreas works as two glands in one. Its hormones keep blood sugar in check, while its digestive juices flow into the intestine just past the stomach to help break down a meal.

In which quadrant of the abdominal cavity does the stomach lie?

Left upper is where it sits, but the stomach is no fixed size or shape. It balloons after a meal, deflates when empty and varies from person to person with build and eating habits.

What was the Ancient Greek word for the stomach?

Gaster lives on in gastric, gastritis and gastronomy. It is in gastropod too: snails and slugs are 'stomach-foots', named for the muscular foot on their underside.

Which letter of the alphabet is the human stomach usually said to resemble?

J is the usual comparison, and the bend is there before birth. In the embryo one wall of the stomach grows faster than the other, curving a simple tube into shape.

Which folds in the stomach lining flatten out as the stomach fills?

Rugae share a root with 'corrugated': the Latin 'ruga', a wrinkle. Like an accordion's pleats, the folds flatten as a meal arrives and return when the stomach empties.

Which nerve, named from the Latin for 'wandering', links the brain to the stomach?

The vagus nerve lives up to its name, wandering from the brain through the neck and chest into the abdomen. Its signals help set the stomach churning and its juices flowing.

Which Scottish dish is traditionally made by boiling minced offal and oatmeal inside a sheep's stomach?

Haggis is sheep's heart, liver and lungs minced with oatmeal and boiled in the animal's stomach, though an artificial casing often stands in for the stomach today.

The word 'fundus', the dome-shaped upper part of the stomach, comes from the Latin for what?

Bottom is what 'fundus' means in Latin, and anatomists use it for the part of a hollow organ farthest from its opening, which in the stomach happens to sit at the top.

The section of the stomach that connects to the duodenum takes its name from a Greek word meaning what?

Gatekeeper is what the Greek 'pyloros' means, and it fits: the pylorus ends in a ring of muscle that acts as a filter, letting only liquid and tiny particles of food move on.

Heartburn strikes when which ring of muscle relaxes at the wrong time and lets stomach acid wash upward?

The lower esophageal sphincter sits at the top of the stomach, and pregnancy, smoking and extra weight can all weaken it, which is why each makes heartburn more likely.

What is the partially digested, semi-fluid mass that leaves the stomach called?

Chyme comes from the Greek for 'juice', and the stomach releases it only a little at a time because a whole meal arriving at once would overwhelm the gut downstream.

Which of these everyday liquids comes closest to the acidity of human stomach acid?

Lemon juice, at about pH 2, is the nearest match; human stomach acid is fiercer than most meat-eaters' and close to that of vultures, which need it to kill the germs in rotting carcasses.

Which acid is the main acidic component of gastric juice?

Hydrochloric acid does more than break food down: it kills many of the bacteria swallowed with a meal and switches on the enzymes that digest protein.

Which cells in the stomach lining pump out its acid?

Parietal cells make the acid with proton pumps, which is why heartburn drugs such as omeprazole, the proton pump inhibitors, work by jamming those pumps.

Which protein-digesting stomach enzyme is released in an inactive form so that it cannot digest the cells that make it?

Pepsin works only in strong acid and falls idle as the pH nears neutral, so it stops cutting proteins once food moves on and the acid is neutralised.

Which scientist's 1904 Nobel Prize honoured his research on digestion rather than the conditioning experiments that made him famous?

Ivan Pavlov won the 1904 prize for showing how nerves control the release of gastric juice, work done by operating on dogs, and their drooling at the lab assistant who fed them began his famous research.

What protects the stomach wall from being digested by its own acid and enzymes?

A layer of mucus and bicarbonate works in two ways: the slime is a physical shield and the bicarbonate neutralises acid that seeps into it, and where the barrier breaks down the juice eats into the wall as an ulcer.

The stomach makes intrinsic factor, a glycoprotein needed to absorb which nutrient?

Vitamin B12 cannot be absorbed without intrinsic factor, so people who have their whole stomach taken out can still live well but need B12 injections.

Which highly contagious virus, notorious for outbreaks on cruise ships, is the most common cause of 'stomach flu'?

Norovirus is no relation of influenza, which infects the nose, throat and lungs, so 'stomach flu' is a misnomer for an illness that real flu viruses never cause.

After a typical meal, the stomach empties completely into the duodenum within how long?

Two to four hours is normal, and doctors test a sluggish stomach against it: the patient eats scrambled egg laced with a radioactive tracer while a camera watches the meal leave over four hours.

Which type of food empties from the stomach fastest?

Foods heavy in carbohydrate leave first, while fat lingers longest because the gut beyond orders the stomach to hold back until the last load is dealt with.

The 'hunger hormone' produced mainly by the stomach is called what?

Ghrelin rises just before a meal and falls once you have eaten, and people who sleep too little carry more of it, which may be why short nights go with bigger appetites.

Which cells in the stomach lining release gastrin, the hormone that tells it to make more acid?

G cells take their letter from gastrin, which they release when protein arrives in the stomach, telling it to make more acid and to churn harder.

Cells in the stomach lining release which chemical messenger, better known as the brain's mood regulator?

Serotonin is mostly a gut chemical: about 90% of the body's supply is made in the digestive tract, where it keeps the gut wall squeezing food along.

The medical term for a stomach rumble, borborygmus, is thought to be what kind of word?

Onomatopoeic words imitate a sound, and this one is thought to echo the gurgle, which comes from the bowels as well as the stomach and sounds louder when they are empty.

What kind of hernia forms when the top of the stomach bulges up through the diaphragm into the chest?

Hiatal hernias are common after the age of 50, and with the stomach out of place it becomes easier for acid to escape upward, which is why they so often bring heartburn.

The ulcer bacterium H. pylori was found in the stomach of which 5,300-year-old mummy?

Ötzi the Iceman shows how long the bug has lived with us: it spread around the world with its human hosts, and only a minority of carriers ever fall ill.

Which Australian doctor drank a beaker of H. pylori culture to prove it causes gastritis?

Barry Marshall had failed to infect animals, so he used himself, telling neither the hospital's ethics committee nor, in any detail, his wife, and was taken aback by how ill he became.

Before a bacterium took the blame, what did doctors think caused most ulcers?

Stress and spicy food took the blame for decades, and both can make an ulcer worse, but neither causes one: most are infections that a short course of antibiotics can cure.

Besides H. pylori, the other common cause of peptic ulcers is heavy use of what?

NSAID painkillers such as aspirin and ibuprofen leave the stomach lining more prone to damage, and the risk climbs with high doses, long use and age.

The first attempt to pass a viewing tube down into the stomach, made in 1868, relied on which kind of performer?

A sword swallower could hold the rigid tube that the German doctor Adolf Kussmaul lit with mirrors and a gasoline lamp; flexible scopes have long since taken its place.

Which silent-film idol died at 31 of a ruptured ulcer, setting off riots among mourning fans in New York?

Rudolph Valentino's case left medicine a term: a perforated ulcer whose pain mimics appendicitis is called Valentino's syndrome.

Which hard mass of swallowed hair or fibre, found in the stomach, was once prized as an antidote to poison?

Bezoar comes from a Persian word for 'antidote', and the stones, usually taken from animals, were once dropped into a drinking cup in the belief that they would neutralise any poison in it.

How was Alexis St. Martin injured, leaving the hole through which his stomach was studied?

Accidentally shot at close range in a fur-trading store, he recovered, but the wound never fully closed, and army surgeon William Beaumont used the opening to watch a living stomach at work.

The US Army surgeon who experimented on Alexis St. Martin became known as the 'Father of' what?

Gastric physiology began on a string: William Beaumont tied food to a thread, lowered it through the hole and pulled it out later to see how much was digested, noting that his subject's bad moods changed the pace.

Alexis St. Martin was what nationality?

Canadian, and a French Canadian at that: he was a voyageur, one of the boatmen who moved goods for the fur companies, and the work took him to the Michigan island where the army surgeon was posted.

Surgical removal of the stomach is called what?

Gastrectomy ends in the Greek for 'cutting out', like tonsillectomy, and people manage without a stomach by eating about six small meals a day in place of three big ones.

Whose autopsy in 1821 pointed to stomach cancer, though rumours of arsenic poisoning persist?

Napoleon Bonaparte's hair later showed raised arsenic, which fed the poisoning theory, but pathologists who re-read the autopsy reports for the bicentenary of his death in 2021 again concluded that stomach cancer killed him.

Which weight-loss operation removes most of the stomach, leaving a pouch about the size and shape of a banana?

A gastric sleeve cannot be undone, because about 80% of the stomach is taken out for good, and as well as leaving less room it may change the gut hormones that drive appetite.

The Roux-en-Y gastric bypass gets the 'Y' in its name from what?

The rearranged shape of the small intestine is a Y, and the 'Roux' is César Roux, the Swiss surgeon who devised the join in the 1890s to get food past a blocked stomach outlet, long before it was used for weight loss.

A cow's stomach has how many compartments?

Four, and only the last of them works like a human stomach, with acid and enzymes; the others ferment and filter the grass, some of which goes back up to be chewed a second time.

Which cheese-making ingredient traditionally comes from the stomach lining of young calves?

Rennet from a calf's stomach curdled the milk for cheese for centuries, which is why strict vegetarians check the label; many cheeses now use substitutes made from plants, fungi or bacteria.

Which compartment of a cow's stomach, also called the paunch, is the largest?

The rumen is a fermenting vat where microbes break down grass the cow could not digest alone, and to ruminate is literally to bring that cud back up and chew it again.

Birds grind food in a muscular stomach called a gizzard, often with the help of what?

Swallowed stones or grit do the chewing for birds, which have no teeth, and the habit is older than birds themselves: gizzard stones turn up inside the fossils of many dinosaurs.

Which pouch in a bird's throat stores food before it moves on to the stomach?

Crop linings can even feed the young: pigeons of both sexes shed a rich fluid called crop milk from the pouch and bring it up for their chicks.

Which sea creature feeds by pushing its stomach out through its mouth and into the shell of its prey?

Starfish pry a clam open a crack with their tube feet, slip the stomach into the gap, digest the animal in its own shell and then draw the stomach back in.

Which of these animals almost never vomits, because the valve at the top of its stomach is so strong?

A horse's stomach is more likely to burst than to empty upward, so when fluid backs up in a bout of colic the vet lets the pressure off through a tube passed down the nose.

The stomach and esophagus form from which part of the embryonic gut?

Foregut is the front section of the embryo's three-part gut tube, and the split lasts for life: in an adult, most organs that grew from it, the stomach included, are still fed by one shared artery.

Which muscle layer does the stomach have that no other part of the digestive tract does?

The inner oblique layer runs at a slant across the usual two, so the stomach can wring and churn a meal as well as squeeze it along, which is how food gets broken up without teeth.

What happens to most of the food a mixing wave drives against the stomach's exit?

It is pushed back, and that is the point: the to-and-fro against a nearly closed exit is what grinds a meal down, so solids shuttle back and forth until they are small enough to leave.

What sets the rhythm of the stomach's mixing waves?

Cells in its wall, the interstitial cells of Cajal, fire on their own like a pacemaker; nerves and hormones change how hard each wave squeezes, but not how often it comes.

Which fatty fold of tissue hangs like an apron from the stomach's outer curve?

The greater omentum is known to surgeons as the policeman of the abdomen, because it drifts toward an infection or wound and wraps around it, walling the trouble off.

Which of these animals has no stomach at all, its esophagus opening straight into the intestine?

The lamprey is not alone in this: the platypus has no working stomach either, and has even lost the genes for making acid.

Which dog breed runs the highest risk of bloat, in which the stomach fills with gas and twists on itself?

Great Danes have the deep, narrow chest that lets a swollen stomach twist, and vets can stitch the stomach to the body wall as a precaution, often while neutering the dog.

Which food, the main ingredient of the Mexican soup menudo, is the lining of a cow's stomach?

Tripe was a cheap, popular staple of working-class Britain until the later 20th century, then fell from favour as the country grew richer, and the tripe shops of its northern towns all but vanished.

The sight or smell of food starts stomach juices flowing in a phase named for which body part?

The head gives the cephalic phase its name, from the Greek for 'head', and the reflex is choosy: the juices flow only for food you actually want, and a lost appetite can switch it off.

Histamine, notorious for the misery of hay fever, also does which job in the stomach?

Histamine triggers the release of acid, which is why heartburn pills such as famotidine work: they jam the stomach's histamine receptors, a different kind from the ones that hay fever tablets block.

How did Australia's extinct gastric-brooding frog avoid digesting the young she carried in her stomach?

She stopped making acid on a chemical cue from the eggs, ate nothing for the six weeks her tadpoles grew inside her, and then gave birth through her mouth; both species vanished in the 1980s.

Which enzyme lets H. pylori survive in stomach acid by making ammonia to neutralise it?

Urease splits urea into ammonia and carbon dioxide, and doctors use that to find the bug: swallow some labelled urea and, if H. pylori is there, the label turns up in your breath minutes later.

Which whip-like tails, bundled at one end of H. pylori, drive the bacterium toward the stomach wall?

Flagella is Latin for 'little whips', and each one spins like a propeller inside a sheath of the bug's own membrane, driving it out of the open stomach to the wall where it settles.