60 free Stomach trivia questions with answers — science & nature quiz, new questions added Aug 2026.
The stomach is a J-shaped bag in the upper left of your abdomen that holds about a litre of food, bathes it in acid with a pH near 2, and empties into the small intestine within a few hours. This quiz covers the anatomy (the cardia, fundus, body and pylorus, the two sphincters, the cells that make acid, pepsin and intrinsic factor), the physiology (why the acid does not digest the stomach itself, what it absorbs, how long food stays) and the illnesses (peptic ulcers, gastritis, stomach cancer, reflux). It also digs into the history and the animal kingdom: William Beaumont peering through a hole in Alexis St. Martin's side in the 1820s, Barry Marshall drinking a beaker of Helicobacter pylori to prove ulcers were an infection, the four-chambered stomach of the cow, the grit-filled gizzard of birds, and what a gastric bypass actually rearranges. Questions run from easy to expert, so it works for a biology class or a pub table. Every answer was checked against Wikipedia's articles on the stomach and related topics, and each question shows the sentence that supports it. Try our digestive system and human body quizzes next.
30 of 60 questions with answers and explanations. Play the quiz
Q 01The stomach sits between the esophagus and which organ?
Small intestine
The first and shortest section of that organ, the duodenum, receives the stomach's output through the pyloric sphincter.
Q 02In which quadrant of the abdominal cavity does the stomach lie?
Left upper
Its top rests against the diaphragm, and it sits on a 'stomach bed' of pancreas, spleen artery, left kidney and colon.
Q 03The Ancient Greek word for the stomach, which gives us the medical prefix 'gastric', is what?
Gaster
The same root gives us gastronomy, gastritis and gastropod, the 'stomach-footed' snails and slugs.
Q 04What letter shape does an empty human stomach roughly resemble?
J
When partly filled it becomes pear-shaped, and when stretched it can hold two to four litres.
Q 05How much food can a normal adult stomach expand to hold?
Around one litre
The maximum in adults is two to four litres, though volumes of up to 15 litres have been recorded in extreme cases.
Q 06Roughly how much can a newborn baby's stomach hold?
About 30 millilitres
That is about two tablespoons, which is why newborns feed so often.
Q 07The human stomach is divided into four sections: the cardia, the fundus, the body and which other?
Pylorus
It ends in the pyloric sphincter, which meters partly digested food out into the duodenum.
Q 08The word 'fundus', the dome-shaped upper part of the stomach, comes from the Latin for what?
Bottom
Anatomists use 'fundus' for the part of a hollow organ farthest from its opening, even when it is at the top.
Q 09The section of the stomach that connects to the duodenum takes its name from a Greek word meaning what?
Gatekeeper
Its sphincter lets only about 3 mL of stomach contents through into the duodenum with each mixing wave.
Q 10The ring of muscle at the junction of the esophagus and stomach is known as what?
Lower esophageal sphincter
When it relaxes at the wrong time, stomach acid washes upward and causes heartburn.
Q 11What is the partially digested, semi-fluid mass that leaves the stomach called?
Chyme
The word comes from the Greek for 'juice'; the ball of chewed food that arrives from the mouth is the bolus.
Q 12Roughly what pH does the stomach maintain for its protein-digesting enzymes?
About 2
That is about as acidic as lemon juice, similar to carrion-eaters that need to kill pathogens in their food.
Q 13Which acid is the main acidic component of gastric juice?
Hydrochloric
Gastric juice is only about 0.5% acid, but that is enough to bring the pH down to between 1 and 3.
Q 21Which type of food empties from the stomach fastest?
Foods heavy in carbohydrate
Fats are digested slowly in the small intestine, so the duodenum signals the stomach to hold back fatty chyme.
Q 22The 'hunger hormone' produced mainly by the stomach is called what?
Ghrelin
Its name comes from a Proto-Indo-European root meaning 'to grow', because it also releases growth hormone.
Q 23Which cells in the pyloric antrum release the acid-stimulating hormone gastrin?
G cells
Its existence was first suggested in 1905, but nobody managed to isolate it until 1964.
Q 14Which cell type in the stomach lining secretes the acid?
Parietal cells
The same cells also make intrinsic factor, and their proton pumps are the target of drugs like omeprazole.
Q 15The stomach's chief cells secrete pepsinogen, which acid converts into which enzyme?
Pepsin
Releasing it as an inactive precursor stops the enzyme from digesting the very cells that make it.
Q 16Which 19th-century scientist discovered pepsin and named it from the Greek for 'digestion'?
Theodor Schwann
He is better known as a founder of cell theory; pepsin was one of the first enzymes ever identified.
Q 17What protects the stomach wall from being digested by its own acid and enzymes?
A layer of mucus and bicarbonate
The lining's column-shaped cells constantly secrete this alkaline slime; when it fails, gastritis and ulcers follow.
Q 18The stomach makes intrinsic factor, a glycoprotein needed to absorb which nutrient?
Vitamin B12
The actual absorption happens far downstream in the ileum, which is why removing the stomach causes pernicious anaemia.
Q 19Roughly what share of the ethanol you drink is absorbed directly through the stomach wall?
10-20%
Most absorption happens in the small intestine, which is why food that slows stomach emptying also slows drunkenness.
Q 20After a typical meal, the stomach empties completely into the duodenum within how long?
Two to four hours
Carbohydrate-heavy meals leave fastest; fatty food can linger for six hours or more.
Q 24The stomach's neuroendocrine cells secrete which neurotransmitter better known for its brain role?
Serotonin
The great majority of the body's supply of this chemical is actually made in the gut, not the head.
Q 25The medical term for a stomach rumble, borborygmus, is thought to be what kind of word?
Onomatopoeic
The Greeks simply spelled the gurgle; the noise is gas and liquid being squeezed along the gut.
Q 26Most peptic ulcers and gastritis are caused by infection with which bacterium?
Helicobacter pylori
The spiral-shaped microbe was formally described in 1983 and was originally named Campylobacter pyloridis.
Q 27Roughly what fraction of the world's population is infected with H. pylori?
About half
Most carriers never notice; only some strains cause ulcers or cancer.
Q 28Which Australian doctor drank a beaker of H. pylori culture to prove it causes gastritis?
Barry Marshall
He developed gastritis within days, and he and Robin Warren shared the 2005 Nobel Prize in Physiology or Medicine.
Q 29In which year did the two Australians who identified H. pylori receive the Nobel Prize for it?
2005
Before their work, medicine blamed ulcers on stress, spicy food and excess acid.
Q 30Besides H. pylori, the other common cause of peptic ulcers is heavy use of what?
NSAID painkillers
Drugs like ibuprofen and aspirin thin the protective mucus layer, and older people are especially sensitive.