Mouth (oral cavity)Also called the oral cavity or buccal cavity. Digestion starts here: the teeth break food into pieces, and an enzyme in saliva begins to break down carbohydrates before anything is swallowed.
Esophagus (food pipe)About 25 cm (10 in) long. It lies behind the trachea and passes through an opening in the diaphragm to reach the stomach. Waves of muscle contraction called peristalsis push each swallowed mouthful down it.
StomachFour regions: cardia, fundus, body and pylorus. Empty, it is about the size of a fist. Full, it holds up to 4 liters. Acid (pH 1.5 to 3.5) and churning turn food into chyme, which leaves through the pyloric sphincter.
Small intestineAbout 3 m (10 ft) long in a living person and only about 2.5 cm (1 in) wide. Most digestion and practically all absorption happen here. Folds, villi and microvilli enlarge its absorbing surface more than 600-fold.
Large intestineAbout 7.6 cm (3 in) wide, more than twice the width of the small intestine, which is why it is called large. Its four regions are the cecum, the colon, the rectum and the anus. It absorbs water, holds trillions of bacteria and forms feces.
RectumThe last 20 cm (8 in) of the alimentary canal. It has three side bends that form internal folds called rectal valves, which help separate feces from gas.
AnusThe opening where the anal canal, the last 3.8 to 5 cm of the canal, reaches the outside. Two sphincters close it: an inner one of smooth muscle that works on its own, and an outer one of skeletal muscle under voluntary control.
LiverThe largest gland in the body, about three pounds in an adult. Its right lobe is far bigger than its left. It makes about a liter of bile a day. Bile breaks large fat globules into small ones, which is called emulsification.
GallbladderA sac 8 to 10 cm (3 to 4 in) long, nested in the back of the liver's right lobe. It stores bile, concentrates it up to 10-fold and, when signaled, pushes it toward the duodenum.
PancreasLies behind the stomach, with its head in the curve of the duodenum and its tail reaching the spleen. It makes over a liter of slightly alkaline pancreatic juice a day, which buffers stomach acid. Its islets make insulin and glucagon.
Alimentary canal, mouth to anus 10
Pharynx (throat)A short tube of skeletal muscle that runs from the back of the oral and nasal cavities to the openings of the esophagus and the larynx. Its top section is used only for breathing and speech. The two lower sections also carry food.
DuodenumThe shortest section of the small intestine, about 25 cm (10 in), beginning at the pyloric sphincter. Bile and pancreatic juice enter it through one shared opening, the hepatopancreatic ampulla.
JejunumAbout 0.9 m (3 ft) long in life, running from the duodenum to the ileum. The name is Latin for empty. No clear boundary separates it from the ileum, so the seam on this drawing is only a guide.
IleumThe longest section of the small intestine, about 1.8 m (6 ft). It is thicker and more vascular than the jejunum. It joins the cecum at the ileocecal sphincter, a valve that is usually closed and keeps contents from flowing back.
CecumA sac about 6 cm (2.4 in) long, the first part of the large intestine. It hangs below the ileocecal valve, receives what the ileum passes on and absorbs water and salts.
AppendixA winding tube about 7.6 cm (3 in) long attached to the cecum. It contains lymphoid tissue. It is generally considered vestigial, though it may keep a reserve of gut bacteria that can restock the intestine.
Ascending colonRuns up the right side of the abdomen from the cecum to the underside of the liver, where it bends at the right colic (hepatic) flexure. It lies behind the peritoneum.
Transverse colonCrosses the abdomen from the right colic flexure, under the liver, to the left colic (splenic) flexure, just below the spleen. A fold of peritoneum called the mesocolon holds it to the back wall of the abdomen.
Descending colonRuns down the left side of the back wall of the abdomen from the left colic (splenic) flexure. Like the ascending colon, it lies behind the peritoneum. In the pelvis it becomes the sigmoid colon.
Sigmoid colonThe S-shaped last section of the colon. It begins where the descending colon enters the pelvis, swings toward the midline and leads into the rectum. The mesocolon holds it in place.
Accessory organs 5
TeethAn accessory organ. A first set has 20 deciduous teeth. A full adult set has 32: 8 incisors, 4 canines, 8 premolars and 12 molars. Enamel, which covers the crown, is the hardest substance in the body.
TongueAn accessory organ attached to the mandible, the hyoid bone and the styloid processes of the temporal bones. It gathers chewed food into a rounded mass called a bolus. A fold called the lingual frenulum tethers it to the floor of the mouth.
Parotid glandOne of three pairs of major salivary glands. It lies between the skin and the masseter muscle, near the ear, and its duct opens into the mouth near the second upper molar.
Sublingual glandOne of three pairs of major salivary glands, lying below the tongue. Together the salivary glands make 1 to 1.5 liters of saliva a day, and 99.4 percent of it is water.
Submandibular glandOne of three pairs of major salivary glands. It sits in the floor of the mouth and sends saliva out through the submandibular duct. Salivary amylase, an enzyme in saliva, starts the breakdown of carbohydrates.
How this list was compiled: Part names, the split into alimentary canal and accessory organs, and the facts in every hint and detail line: OpenStax Anatomy and Physiology 2e, chapter 23, sections 23.1 and 23.3 to 23.6, https://openstax.org/books/anatomy-and-physiology-2e/pages/23-1-overview-of-the-digestive-system, read 2026-09-19, CC BY 4.0. The simple set of 10: the organ list of the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works, read 2026-09-19, with the rectum added. Everyday names, read 2026-09-19: https://en.wikipedia.org/wiki/Small_intestine, https://en.wikipedia.org/wiki/Large_intestine, https://en.wikipedia.org/wiki/Appendix_(anatomy), https://en.wikipedia.org/wiki/Ileum, https://en.wikipedia.org/wiki/Ilium_(bone), https://en.wikipedia.org/wiki/Stomach; gullet, https://en.wikipedia.org/wiki/Esophagus, and GI tract, https://en.wikipedia.org/wiki/Gastrointestinal_tract, read 2026-09-20. The class 7 figure and the name food pipe: Curiosity, Grade 7, chapter 9, Fig. 9.1, National Council of Educational Research and Training, https://ncert.nic.in/textbook/pdf/gecu109.pdf, read 2026-09-20. The wording of every line is our own. Licence: own work
The drawing: Drawn for this site, 2026-09-20. Own work; no picture was used as a reference. Positions and proportions checked against the text of the Wikipedia articles Human digestive system, Large intestine, Small intestine, Jejunum, Ileum, Rectum and Parotid gland. Licence: own work
How it works
One drawing holds all 25 parts. Numbers 1 to 17 follow food along the alimentary canal, from the mouth to the anus. Numbers 18 to 25 are the accessory organs: teeth, tongue, three salivary glands, liver, gallbladder and pancreas.
Read the full guide
Mouth to anus in 17 numbers
This labeled diagram of the digestive system numbers the canal in the order food travels, mouth (1) to anus (17). The small intestine (5) and the large intestine (9) are parts too: their rings sit in the margins, and the whole organ lights up. The body's right is on the left of the drawing, so the liver is on your left.
Six sets, from 10 parts to 25
Simple is a digestive system diagram for kids: 10 main organs. Alimentary canal is a digestive tract quiz of 17 parts, with the accessory organs labeled 18 to 25 as a set of their own. Small and large intestine has 13. If you type answers, gullet and food pipe both count for the esophagus.
Ileum with an e is the end of the small intestine. Ilium with an i is part of the hip bone.
For a digestive system diagram project, sketch the canal in number order first, then add the accessory organs around it.
For a digestive system labeling game in class, project the quiz and let teams take turns tapping the part it names.
Questions and answers
Which parts belong on a digestive system diagram kids label in school?
Start with Simple: mouth, esophagus, stomach, small intestine, large intestine, rectum, anus, liver, gallbladder and pancreas. The human digestive system diagram class 7 pupils label in Curiosity, India's national science textbook, has nine of these 10: every one but the gallbladder.
Is there a blank digestive system diagram to label, PDF or paper?
Yes. Print blank gives the digestive system diagram unlabeled, as a digestive tract worksheet: rings numbered 1 to 25 with an answer line for each. Print labelled adds the names. Choose Save as PDF for a file. It is line art to color in.
What is the order of the digestive system?
Mouth, pharynx, esophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine (cecum, colon, rectum, anus). That path, the gastrointestinal (GI) tract, is numbers 1 to 17 here, with the appendix as a side branch at 11.
Can I use this for the art labeling activity: overview of the digestive system?
To learn the names, yes. The full set works as a digestive anatomy labeling quiz, down to the jejunum and the sigmoid colon. It is our own drawing, not a publisher's figure, so numbers and layout differ, and it is no answer key.