Gastrointestinal Terms and Definitions

Gustatory

Related to the sense of taste.

Three Pairs of Salivary Glands (Where are they?)

Parotid glands: near the ears; submandibular glands: beneath the jaw; sublingual glands: beneath the tongue.

Deglutition

Swallowing; the process of moving food from the mouth through the pharynx and esophagus.

Pharynx

The throat; a muscular passageway shared by the respiratory and digestive systems.

Peristalsis

Rhythmic, wave-like contractions of smooth muscle that move contents through the digestive tract.

Gastric

Pertaining to the stomach.

Rugae

Folds in the lining of the stomach that allow it to expand as it fills.

Sphincters (Lower Esophageal and Pyloric Sphincter)

Muscular valves that regulate passage through the GI tract; the lower esophageal sphincter controls entry into the stomach, while the pyloric sphincter controls passage into the duodenum.

Chyme

A semi-fluid mixture of partially digested food and gastric secretions leaving the stomach.

Small Intestine

The GI organ where most chemical digestion and nutrient absorption occur; it includes the duodenum, jejunum, and ileum.

Duodenum

The first and shortest part of the small intestine; it receives chyme, bile, and pancreatic secretions.

Jejunum

The middle section of the small intestine and a major site of nutrient absorption.

Ileum

The final section of the small intestine; it absorbs remaining nutrients and passes contents into the large intestine.

Cecum

The first pouch-like portion of the large intestine, located where the ileum joins the colon.

Appendix

A narrow, fingerlike tube attached to the cecum that contains lymphoid tissue.

Colon

The main portion of the large intestine, consisting of the ascending, transverse, descending, and sigmoid sections.

Ascending Colon

The first section of the colon; travels upward along the right side of the abdomen.

Transverse Colon

The section of the colon that travels horizontally across the upper abdomen.

Descending Colon

The section of the colon that travels downward along the left side of the abdomen.

Sigmoid Colon

The S-shaped final section of the colon that connects to the rectum.

Rectum

The final straight portion of the large intestine that stores feces before elimination.

Anal Sphincter

A ring of muscle that controls the release of feces through the anus.

Peritoneum

A thin serous membrane lining the abdominal and pelvic cavities and covering many abdominal organs.

Peritoneal Fluid

A small amount of lubricating fluid between layers of the peritoneum that reduces friction between abdominal organs.

Liver

A large accessory digestive organ that processes nutrients, detoxifies substances, produces bile, and performs many metabolic functions.

Hepatocytes

The primary functional cells of the liver that perform most of its metabolic, detoxification, and bile-producing functions.

Bile

A fluid produced by the liver that helps emulsify fats for digestion and absorption.

Biliary Tree

The network of ducts that carries bile from the liver and gallbladder to the duodenum.

Pancreas

An organ behind the stomach that produces digestive enzymes and bicarbonate and also produces hormones such as insulin.

Cholecystokinin

A hormone released by the small intestine in response to fats and proteins; it stimulates pancreatic enzyme secretion and gallbladder contraction.

Emulsification

The physical breakup of large fat droplets into smaller droplets by bile, increasing surface area for digestive enzymes.

Amylase

An enzyme that begins carbohydrate digestion by breaking starch and glycogen into smaller carbohydrates.

Dysphagia

Difficulty or discomfort with swallowing.

Polyphagia

Excessive hunger or increased appetite.

Cheilitis

Inflammation of the lips.

Sialolithiasis

Formation of a stone in a salivary gland or its duct, which can obstruct saliva flow.

Stomatitis

Inflammation of the mucous lining of the mouth.

Glossitis

Inflammation of the tongue.

Dyspepsia

Indigestion; a group of symptoms such as upper abdominal discomfort, fullness, bloating, or burning.

Esophageal Varices

Enlarged, fragile veins in the esophagus that can bleed severely, often due to portal hypertension.

Gastritis

Inflammation of the stomach lining.

Gastroenteritis

Inflammation of the stomach and intestines, commonly caused by infection and often producing vomiting and diarrhea.

Esophagitis

Inflammation of the esophagus.

Pyrosis

Heartburn; a burning sensation behind the breastbone, commonly caused by acid reflux.

Hematemesis

Vomiting blood.

Emesis

The act of vomiting or the material expelled by vomiting.

Peptic Ulcer Disease

A condition involving an ulcer in the stomach or duodenal lining, commonly associated with H. pylori infection or NSAID use.

H. pylori

a bacterium that can infect the stomach lining and contribute to gastritis and peptic ulcers.

Ileus

A temporary lack of normal intestinal movement that prevents or slows passage of intestinal contents.

Intussusception

A condition in which one segment of intestine slides into an adjacent segment, potentially causing obstruction and loss of blood flow.

Volvulus

Twisting of the intestine around itself or its supporting tissue, potentially causing obstruction and reduced blood flow.

Appendicitis

Inflammation of the appendix, usually caused by obstruction of its opening.

Colic

Cramping abdominal pain caused by spasms of a hollow organ, often occurring in waves.

Diverticulum

An abnormal pouch projecting from the wall of a hollow organ

Diverticulosis

The presence of diverticula, usually in the colon, without significant inflammation.

Diverticulitis

Inflammation, and sometimes infection, of one or more diverticula.

Dysentery

An intestinal infection or inflammatory condition causing diarrhea, often with blood and mucus and abdominal pain.

Gluten Enteropathy/Celiac Disease

An autoimmune disorder in which gluten triggers damage to the small-intestinal lining, impairing nutrient absorption.

Inflammatory Bowel Disease (2 Types)

Chronic inflammatory disorders of the GI tract: Crohn disease and ulcerative colitis.

Irritable Bowel Syndrome

A disorder of gut-brain interaction causing recurrent abdominal pain associated with changes in bowel habits, without visible structural disease.

Polyps

Abnormal tissue growths projecting from the lining of an organ, especially the colon; some can become cancerous.

Hemorrhoids

Swollen veins and supporting tissue in the lower rectum or anus that may cause bleeding, itching, or discomfort.

Proctitis

Inflammation of the rectum.

Rectocele

A bulging of the rectal wall into the vagina, usually caused by weakening of supporting tissues.

Hematochezia

the passage of fresh, bright red or maroon blood through the rectum during bowel movements

Steatorrhea

Bulky, pale, greasy, foul-smelling stools caused by excess fat in the feces.

Peritonitis

Inflammation of the peritoneum, often caused by infection or leakage of GI contents into the abdominal cavity.

Ascites

Abnormal accumulation of fluid in the abdominal cavity.

Cirrhosis

Advanced, permanent scarring and structural distortion of the liver that impairs liver function.

Hepatitis

Inflammation of the liver, caused by viruses, alcohol, medications, autoimmune disease, or other factors.

Hepatomegaly

Abnormal enlargement of the liver.

Jaundice

Yellowing of the skin, sclera, or mucous membranes caused by elevated bilirubin.

Bilirubin

A yellow pigment produced from breakdown of hemoglobin and processed by the liver for elimination in bile.

Liver Cancer

Malignant cancer arising in the liver; hepatocellular carcinoma is the most common primary liver cancer in adults.

Cholangitis

Inflammation and usually infection of the bile ducts, often caused by obstruction.

Cholecystitis

Inflammation of the gallbladder, most commonly caused by a gallstone blocking the cystic duct.

Cholelithiasis

The presence of gallstones in the gallbladder.

Pancreatic Cancer

Malignant cancer arising in pancreatic tissue, most commonly pancreatic ductal adenocarcinoma.

Cholangiography

Imaging of the bile ducts using contrast to identify abnormalities such as obstruction or stones.

CAT / CT Scan

Computed tomography, an imaging method that uses X-rays and computer processing to create detailed cross-sectional images.

Magnetic Resonance Imaging (MRI)

An imaging technique using magnetic fields and radio waves to produce detailed images of internal tissues and organs.

Upper GI Series

An X-ray examination of the upper digestive tract after swallowing a contrast material, usually barium.

Nasogastric Tube (NG)

A flexible tube passed through the nose into the stomach for feeding, medication, drainage, or decompression.

Abdominocentesis

A procedure that uses a needle to remove fluid from the abdominal cavity, often for diagnosis or treatment of ascites.

Bariatric Surgery

Surgery that helps treat severe obesity by reducing stomach capacity, altering digestion, or both.

Cholecystectomy

Surgical removal of the gallbladder.

Colostomy

Surgical creation of an opening from the colon through the abdominal wall to divert stool into an external pouch.

Endoscopy

A procedure using a flexible or rigid instrument with a camera to examine the inside of a body cavity or organ.

Antiemetics

Medications used to prevent or treat nausea and vomiting.

H2 Blocker Drugs

Medications that reduce stomach acid production by blocking histamine H2 receptors on stomach parietal cells.

Proton Pump Inhibitor Drugs

Medications that strongly reduce stomach acid production by blocking the gastric proton pump in parietal cells.