60 Fun Facts About Stomach

The stomach sits between the esophagus and which organ?

The first and shortest section of that organ, the duodenum, receives the stomach's output through the pyloric sphincter.

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

Its top rests against the diaphragm, and it sits on a 'stomach bed' of pancreas, spleen artery, left kidney and colon.

The Ancient Greek word for the stomach, which gives us the medical prefix 'gastric', is what?

The same root gives us gastronomy, gastritis and gastropod, the 'stomach-footed' snails and slugs.

What letter shape does an empty human stomach roughly resemble?

When partly filled it becomes pear-shaped, and when stretched it can hold two to four litres.

How much food can a normal adult stomach expand to hold?

The maximum in adults is two to four litres, though volumes of up to 15 litres have been recorded in extreme cases.

Roughly how much can a newborn baby's stomach hold?

That is about two tablespoons, which is why newborns feed so often.

The human stomach is divided into four sections: the cardia, the fundus, the body and which other?

It ends in the pyloric sphincter, which meters partly digested food out into the duodenum.

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

Anatomists use 'fundus' for the part of a hollow organ farthest from its opening, even when it is at the top.

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

Its sphincter lets only about 3 mL of stomach contents through into the duodenum with each mixing wave.

The ring of muscle at the junction of the esophagus and stomach is known as what?

When it relaxes at the wrong time, stomach acid washes upward and causes heartburn.

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

The word comes from the Greek for 'juice'; the ball of chewed food that arrives from the mouth is the bolus.

Roughly what pH does the stomach maintain for its protein-digesting enzymes?

That is about as acidic as lemon juice, similar to carrion-eaters that need to kill pathogens in their food.

Which acid is the main acidic component of gastric juice?

Gastric juice is only about 0.5% acid, but that is enough to bring the pH down to between 1 and 3.

Which cell type in the stomach lining secretes the acid?

The same cells also make intrinsic factor, and their proton pumps are the target of drugs like omeprazole.

The stomach's chief cells secrete pepsinogen, which acid converts into which enzyme?

Releasing it as an inactive precursor stops the enzyme from digesting the very cells that make it.

Which 19th-century scientist discovered pepsin and named it from the Greek for 'digestion'?

He is better known as a founder of cell theory; pepsin was one of the first enzymes ever identified.

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

The lining's column-shaped cells constantly secrete this alkaline slime; when it fails, gastritis and ulcers follow.

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

The actual absorption happens far downstream in the ileum, which is why removing the stomach causes pernicious anaemia.

Roughly what share of the ethanol you drink is absorbed directly through the stomach wall?

Most absorption happens in the small intestine, which is why food that slows stomach emptying also slows drunkenness.

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

Carbohydrate-heavy meals leave fastest; fatty food can linger for six hours or more.

Which type of food empties from the stomach fastest?

Fats are digested slowly in the small intestine, so the duodenum signals the stomach to hold back fatty chyme.

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

Its name comes from a Proto-Indo-European root meaning 'to grow', because it also releases growth hormone.

Which cells in the pyloric antrum release the acid-stimulating hormone gastrin?

Its existence was first suggested in 1905, but nobody managed to isolate it until 1964.

The stomach's neuroendocrine cells secrete which neurotransmitter better known for its brain role?

The great majority of the body's supply of this chemical is actually made in the gut, not the head.

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

The Greeks simply spelled the gurgle; the noise is gas and liquid being squeezed along the gut.

Most peptic ulcers and gastritis are caused by infection with which bacterium?

The spiral-shaped microbe was formally described in 1983 and was originally named Campylobacter pyloridis.

Roughly what fraction of the world's population is infected with H. pylori?

Most carriers never notice; only some strains cause ulcers or cancer.

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

He developed gastritis within days, and he and Robin Warren shared the 2005 Nobel Prize in Physiology or Medicine.

In which year did the two Australians who identified H. pylori receive the Nobel Prize for it?

Before their work, medicine blamed ulcers on stress, spicy food and excess acid.

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

Drugs like ibuprofen and aspirin thin the protective mucus layer, and older people are especially sensitive.

About what percentage of people develop a peptic ulcer at some point in their life?

At any one time about 4% of the population has one, and bleeding occurs in up to 15% of cases.

The first recorded description of a perforated peptic ulcer, in 1670, concerned which royal?

Charles II's sister died suddenly in France at 26, and the autopsy became a landmark case.

A stress ulcer that develops after severe burns is named after which person?

The other eponym in the pair applies after major surgery or brain trauma.

Alexis St. Martin, whose stomach was studied through a hole in his side, was injured how in 1822?

The wound never closed, leaving a fistula that let army surgeon William Beaumont watch digestion happen.

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

William Beaumont dangled food on strings into the fistula and timed how long each took to digest.

Alexis St. Martin was what nationality?

The voyageur outlived his doctor by decades, dying in 1880 at 78 with the hole in his side still open.

Surgical removal of the stomach is called what?

It is done for cancer or a perforated stomach wall; removing just the cardia is a cardiectomy.

In 2018 global figures, stomach cancer ranked where among causes of cancer death?

It caused about 9% of cancer deaths that year, and Japan and South Korea screen for it because their rates are so high.

In gastric bypass surgery, the stomach is divided into a small upper section and what?

The small intestine is then rerouted in a Y shape to connect to both, in the Roux-en-Y procedure.

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

The Roux-en-Y bypass has been done laparoscopically since 1993-94 and is one of the hardest keyhole operations.

A cow's stomach has how many compartments?

Only the last of the four works like a human stomach; the others ferment, filter and send grass back up to be chewed again.

Which compartment of a ruminant's stomach is described as the 'true stomach'?

The others are fermentation vats and filters; this one secretes acid and enzymes as ours does.

The largest compartment of a ruminant's stomach, also called the paunch, is the what?

Together with the reticulum it makes up about 80% of the total stomach volume and hosts billions of microbes.

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

The swallowed pebbles, called gastroliths, become smooth and round from constant polishing.

The word 'gizzard' ultimately derives from a Latin word meaning what?

It reached English via Old French gésier and Middle English giser.

Which of these animals has a gizzard but no stomach at all?

In grasshoppers the gizzard comes before the stomach, and in birds it comes after.

The vomiting trigger zone in the brain, the area postrema, sits on the floor of which structure?

It lies outside the blood-brain barrier, which is why drugs in the bloodstream can make you sick.

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

The gut tube starts to differentiate in the third week of development as the embryo folds around the yolk sac.

Which muscle layer is unique to the stomach among parts of the gastrointestinal tract?

Its angled fibres create the churning motion that physically breaks food down.

Roughly how much chyme does each mixing wave push through the pyloric sphincter?

The rest is pushed back into the body of the stomach to keep mixing until the next wave.

Mixing waves begin in a full stomach at intervals of roughly how many seconds?

They start gentle and intensify as they travel from the body of the stomach toward the pylorus.

What is the large peritoneal fold that hangs like an apron from the stomach's outer curve?

The lesser omentum, by contrast, develops from the ventral mesentery and attaches to the liver.

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

Hagfishes, chimaeras, lungfishes and some teleost fish share the same stomach-free design.

The smooth channel along the lesser curvature that speeds liquids to the pylorus is the what?

Food, by contrast, loops around the fundus and body as it is churned into chyme.

About how much gastric juice does a typical adult stomach secrete each day?

The freshly secreted acid can be as low as pH 0.8 before dilution in the stomach.

Roughly what share of the acid for a meal is released during the gastric phase of secretion?

The final 10% comes in the intestinal phase once chyme reaches the small intestine.

Which messenger from enterochromaffin-like cells most strongly stimulates acid secretion?

That is why H2 blockers, which block histamine receptors, reduce stomach acid.

Under which genus was the ulcer bacterium H. pylori first classified?

Its new genus name comes from the helical body thought to help it burrow through the stomach's mucus.

Which enzyme, about 10% of its protein, lets H. pylori neutralise acid by splitting urea?

The reaction releases ammonia and bicarbonate, raising the local pH so the bacterium can survive.

How many flagella does H. pylori carry at one pole?

The flagella are sheathed in outer membrane for protection against acid and can even turn into adhesive structures in biofilms.