absorbTo take a substance in through a surface. Water and digested nutrients are absorbed through the small intestine's walls into the blood.
digestive systemThe organs that break food down and take it in. It is one long twisting tube that starts at the mouth, with the liver, pancreas and gallbladder beside it.
enzymeA molecule made by cells that hurries a reaction. Most enzymes are proteins. Digestive enzymes cut large food molecules into small ones.
esophagusThe food pipe that runs down behind the windpipe. It is about 25 centimeters (10 inches) long in an adult. Gullet is another name for it.
gallbladderThe small pouch that stores bile between meals. It sits beneath the liver and is shaped like a pear.
large intestineThe wide tube that takes water from leftover food. It is the shorter of the two intestines. The appendix, cecum, colon and rectum are its parts.
liverWhere bile is produced and nutrients are processed. Blood from the small intestine brings it sugars and amino acids, which it stores and sends on when the body needs them.
mouthThe opening where food enters and chewing begins. Digestion starts here, as soon as chewing begins.
Show all 36 terms (28 more)
The digestive system, continued
nutrientAnything in food that keeps a body alive and growing. Carbohydrates, proteins, fats, vitamins, minerals and water are all nutrients.
pancreasThe gland that sends enzymes to the small intestine. Its enzymes work on carbohydrates, fats and proteins. It also makes the hormone insulin.
small intestineThe longest section of gut, folded many times over. Most nutrients are absorbed here. It is about 6.5 meters (21 feet) long, in three parts: the duodenum, the jejunum and the ileum.
stomachThe muscle-walled bag that holds and mashes a meal. It mixes food with acid and enzymes, then slowly empties the mixture, called chyme, into the small intestine.
How food is broken down 12
bileThe liver's juice, which breaks fat into droplets. It is yellow-green. The gallbladder stores it and releases it into the small intestine after a meal.
chemical digestionThe splitting of food molecules by enzymes and acid. Proteins break into amino acids, fats into fatty acids and glycerol, carbohydrates into simple sugars.
digestionTurning a meal into molecules the blood can carry. The body uses what it gets for energy, growth and cell repair.
fecesThe solid waste left after food is digested. It holds undigested food, bacteria and worn-out cells shed by the gut lining. Stool is another word for it.
mechanical digestionCutting, grinding and churning food into small bits. Chewing does it in the mouth, and the muscles of the stomach keep it going.
pancreatic juiceThe enzyme-rich fluid the pancreas makes. It is alkaline, so it neutralizes stomach acid as food enters the small intestine.
peristalsisWaves of muscle squeezing that push food along. The muscle behind the food tightens while the muscle in front of it relaxes.
rectumThe large intestine's last stretch, where waste waits. It is about 12 centimeters long in an adult. Waste leaves the body through the opening just below it.
salivary glandsThe organs that make saliva and send it to the mouth. People have three large pairs and hundreds of tiny ones. Saliva is about 99 percent water, with an enzyme that starts on starch.
stomach acidThe strong acid in the stomach's juice. It is hydrochloric acid. It guards against germs in food and switches on enzymes that digest protein.
teethThe mouth's tools for biting and chewing. A full adult set is 32. Incisors cut, canines tear, and premolars and molars crush.
villiSmall projections that carpet the inside of the gut. One is a villus, about a millimeter long and shaped like a finger. Together they give the small intestine far more surface for absorbing.
Juices, nutrients and more 12
assimilationThe use of absorbed nutrients by the body's cells. It comes after digestion and absorption: the nutrients are built into the body or used for growth and repair.
bowelAnother word for the intestine. The small intestine is also the small bowel, and the large intestine the large bowel.
digestive juiceAny fluid the body makes to break food down. Saliva, stomach acid and bile are digestive juices.
egestionGetting rid of food that could not be digested. The verb is egest. Its opposite is ingestion, taking food in.
glandAn organ whose job is to produce a fluid or hormone. Glands in the lining of the stomach make its acid and enzymes.
gutThe digestive tube as a whole; the GI tract. GI stands for gastrointestinal. Each organ along it is hollow, and each opens into the next.
hormoneA signal chemical that travels in the bloodstream. Cells lining the stomach and small intestine make hormones that tell the body when to release digestive juices.
lipidA fat, an oil or a similar substance. Fats, waxes and some vitamins are lipids. The body stores energy in them.
masticationThe scientific word for chewing. The tongue and cheeks keep the food between the teeth. The soft ball that is swallowed is called a bolus.
solubleCapable of dissolving in water or another liquid. Digestion turns large food molecules that will not dissolve into small soluble ones.
taste budA tiny organ on the tongue that detects sweet or sour. Taste buds also pick up salty, bitter and savory, and any part of the tongue can sense all five.
throatThe front of the neck and the passage inside it. During a swallow a flap called the epiglottis drops over the airway, so food goes down the esophagus.
How this list was compiled: Term list chosen for this site on 2026-10-12. Each meaning is written in our own words and was checked that day against the article on the term in the English Wikipedia (https://en.wikipedia.org/), whose text is under the Creative Commons Attribution-ShareAlike license: Human digestive system, Digestion, Human mouth, Esophagus, Stomach, Small intestine, Large intestine, Liver, Pancreas, Gallbladder, Enzyme, Digestive enzyme, Nutrient, Human tooth, Saliva, Salivary gland, Gastric acid, Gastric mucosal barrier, Bile, Peristalsis, Intestinal villus, Feces, Rectum, Gastrointestinal tract, Throat, Pharynx, Taste bud, Chewing, Food bolus, Gland, Pancreatic juice, Lipid, Assimilation (biology) and Hormone. Absorb, soluble, mastication, egestion, egest, gut and bowel rest on their entries in Wiktionary, the free dictionary (https://en.wiktionary.org/). The organs and what each does, the nutrients, what proteins, fats and carbohydrates break into, peristalsis, the digestive juices, the liver, the waste and the hormones were checked a second time against Your Digestive System & How it Works of the National Institute of Diabetes and Digestive and Kidney Diseases (https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works). The swallow and the accessory organs were checked against the Digestive System pages of the SEER Training Modules of the National Cancer Institute (https://training.seer.cancer.gov/anatomy/digestive/). The fact after each meaning is from the same pages. Licence: own work
How it works
This digestive system vocabulary worksheet prints twelve terms, among them esophagus, stomach, small intestine, liver, pancreas, enzyme and absorb, to match to their meanings, with a key as the last page. Words and meanings only: no diagram to label.
Read the full guide
How food is broken down
Set opens on The digestive system. The second set has digestion, mechanical digestion, chemical digestion, teeth, salivary glands, stomach acid, bile, pancreatic juice, peristalsis, villi, rectum and feces.
Juices, nutrients and more
The third set has throat, taste bud, mastication, gland, digestive juice, soluble, lipid, assimilation, egestion, hormone, gut and bowel.
Bolus, chyme, and the duodenum, jejunum, ileum, cecum and colon are named in the facts under the tool, not on the sheet.
Questions and answers
What are the accessory organs of the digestive system?
The organs that help digestion without food ever passing through them: the salivary glands, the liver, the gallbladder and the pancreas. They send saliva, bile and enzymes into the digestive tract.
What enzymes break down food?
Amylases split starch and other carbohydrates into simple sugars, proteases split proteins into amino acids, and lipases split fats. Saliva, the stomach, the pancreas and the small intestine all supply digestive enzymes.
Why doesn't stomach acid harm the stomach?
The lining of the stomach covers itself with a gel-like layer of mucus, with a thin layer of fluid rich in bicarbonate beneath it. The mucus slows the acid, and the bicarbonate neutralizes what gets through.