Digestive System Mechanisms and Terminology

A complete set of vocabulary flashcards covering the organs, processes, medical terms, and diagnostic procedures of the human digestive system.

Digestion

The process by which food is broken down mechanically and chemically in the gastrointestinal tract and converted into an absorbable form used by the cells of the body.

Ingestion

The first phase of digestion, defined as taking food into the digestive tract.

Deciduous Teeth

Also known as baby teeth; they begin to appear at about age $6\text{ months}$ and are exchanged for adult permanent teeth starting at about age $6\text{ years}$.

Salivary Glands

Exocrine glands that produce about $1.5\text{ L}$ of saliva per day containing enzymes to break down carbohydrates and moisture to enable taste perception.

Pharynx

Part of the throat located behind the mouth and nasal cavity that routes air to the larynx and directs food and liquids into the esophagus.

Esophagus

A hollow, tubular organ $9$ to $10\text{ inches}$ long connecting the pharynx to the stomach.

Peristalsis

Involuntary, wave-like smooth muscle contractions that move food throughout the gastrointestinal tract.

Emesis

Vomiting; occurs when built-up pressure and reverse peristalsis in the stomach force contents back out through the mouth.

Cardiac Sphincter

The circular muscle controlling the upper opening to the stomach from the esophagus.

Pyloric Sphincter

The lowermost muscular opening of the stomach that connects it to the small intestine.

Chyme

An acidic semi-liquid mixture formed in the stomach consisting of partially digested food, digestive secretions, and worn-out cells.

Hydrochloric Acid (HCl)

Stomach acid with a pH of $1.5$ to $3.5$ that breaks down proteins, kills bacteria, and converts inactive pepsinogen into active pepsin.

Gastric Glands

Approximately $35\text{ million}$ glands in the stomach lining located in the fundus, body, and pylorus that secrete gastric juice containing hydrochloric acid and digestive enzymes.

Duodenum

The $9\text{-inch}$ C-shaped first section of the small intestine.

Jejunum

The $8\text{-foot}$ long middle section of the small intestine where nutrient absorption from solid foods primary occurs.

Ileum

The $12\text{-foot}$ long final section of the small intestine.

Villi

Tiny, finger-like, highly vascular projections lining the surface of the small intestine that sway with peristalsis to absorb nutrients into the bloodstream.

Ileocecal Valve

The valve located between the small intestine and large intestine that prevents material from flowing back into the small intestine.

Secretin

A hormone produced in the small intestine that aids in the digestive process.

Bile

A liquid made in the liver and stored in the gallbladder that breaks down fats and other nutrients.

Cirrhosis

Extensive scarring of liver tissue that renders the liver hard and unable to perform detoxification functions.

Amino Acids

Organic compounds that serve as the building blocks of proteins, categorized as essential, nonessential, or conditional.

Trypsin

An enzyme secreted by the pancreas that breaks down proteins.

Pancreatic Lipase

A pancreatic digestive enzyme responsible for breaking down fats.

Pancreatic Amylase

An enzyme produced by the pancreas and salivary glands that breaks down carbohydrates and starches.

Achalasia

Decreased mobility of the lower two-thirds of the esophagus along with constriction of the lower esophageal sphincter.

Appendicitis

Acute inflammation of the vermiform appendix that can lead to perforation and peritonitis.

Achlorhydria

An abnormal condition characterized by the absence of hydrochloric acid in gastric juice.

Aphagia

The loss of the ability to swallow due to organic or psychologic causes.

Ascites

An abnormal accumulation of protein- and electrolyte-rich fluid within the peritoneal cavity.

Anal Fistula

An abnormal passageway on the skin surface near the anus, usually connecting with the rectum.

Crohn's Disease

Chronic inflammation of the digestive tract causing fever, cramping, diarrhea, weight loss, and anorexia.

Dysentery

Painful intestinal inflammation caused by ingesting contaminated food or water, leading to frequent stools often containing blood.

Esophageal Varices

Swollen, twisted (tortuous) veins located in the distal end of the esophagus.

Cholelithiasis

The presence of pigmented or hardened cholesterol stones formed due to bile crystallization.

Cholecystitis

Redness and inflammation of the gallbladder.

Gastrin

A hormone that stimulates stomach cells to produce acid; excessive amounts can cause gastritis and peptic ulcers.

Hemorrhoids

An unnaturally distended or swollen vein (varicosity) located in the distal rectum or anus.

Hernia

An irregular protrusion of a tissue, organ, or portion of an organ through an abnormal break in the surrounding cavity's muscular wall.

Hirschsprung's Disease

Congenital absence of autonomic ganglia in a segment of the intestinal smooth muscle wall, preventing normal peristalsis.

Intussusception

Telescoping of a portion of proximal intestine into distal intestine, typically in the ileocecal region, causing bowel obstruction.

Oral Leukoplakia

A precancerous white lesion occurring anywhere in the oral cavity.

Colorectal Polyps

Small growths projecting from the mucous membrane of the colon or rectum that can be sessile (flat) or pedunculated (stemmed).

Thrush

A fungal infection of the mouth and throat caused by Candida albicans, producing raised curd-like white patches.

Volvulus

Rotation or twisting of loops of bowel upon itself, leading to intestinal obstruction.

Abdominocentesis

Also called paracentesis; insertion of a needle or trocar into the abdominal cavity to withdraw accumulated fluid.

Barium Swallow

An upper GI diagnostic series using oral administration of radiopaque barium sulfate to visualize swallowing and esophageal structure.

Cheiloplasty

Surgical repair or correction of a defect of the lip.

Cholecystectomy

Surgical removal of the gallbladder.

Colonoscopy

Direct visual examination of the inner lining of the large intestine using a flexible fiberoptic colonoscope.

Colostomy

Surgical creation of an artificial opening on the abdominal wall through which fecal waste is diverted and expelled.

Endoscopic Retrograde Cholangiopancreatography

A procedure using a fiberoptic endoscope and radiopaque dye to examine the size and condition of pancreatic and biliary ducts.

Stool Guaiac Test

A diagnostic test using guaiac reagent on a stool specimen to check for unseen (occult) blood.