Level 1: CH 19 Digestive System Vocabulary

A comprehensive set of vocabulary flashcards covering key structures, processes, enzymes, hormones, and disorders of the digestive system as presented in the lecture notes.

Absorption

Movement of digested nutrients, water, and ions from the digestive tract into blood or lymph.

Ingestion

The act of taking food or drink into the mouth.

Digestion

Chemical and mechanical breakdown of food into nutrients small enough to be absorbed.

Defecation

Elimination of undigested waste (feces) from the large intestine through the anus.

Peristalsis

Wave-like smooth-muscle contractions that propel material through the digestive tract.

Segmentation

Rhythmic local contractions of the small intestine that mix chyme with digestive juices.

Peritoneum

Large serous membrane lining the abdominopelvic cavity and covering its organs.

Parietal peritoneum

Portion of peritoneum that lines the body wall of the abdominopelvic cavity.

Visceral peritoneum

Portion of peritoneum that covers and adheres to the abdominal organs.

Mesentery

Double layer of peritoneum that suspends and anchors abdominal organs, carrying blood vessels and nerves.

Oral cavity

Mouth; contains tongue, teeth, and salivary gland openings; site of ingestion and mastication.

Mastication

Chewing; mechanical grinding of food by teeth.

Deglutition

Swallowing; movement of a bolus from the mouth to the stomach.

Bolus

Soft mass of chewed food mixed with saliva ready for swallowing.

Esophagus

Muscular tube that transports bolus from pharynx to stomach by peristalsis.

Lower esophageal sphincter (LES)

Ring of muscle at distal esophagus that prevents gastric reflux into the esophagus.

Stomach

J-shaped organ that stores food, secretes gastric juice, and begins protein digestion.

Pyloric sphincter

Valve regulating passage of chyme from stomach to duodenum.

Rugae

Folds in the stomach lining that allow expansion after meals.

Chyme

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

Hydrochloric acid (HCl)

Strong acid in gastric juice that denatures proteins, kills microbes, and activates pepsin.

Pepsin

Active gastric enzyme that begins protein digestion; formed from pepsinogen + HCl.

Small intestine

Longest digestive tract section (duodenum, jejunum, ileum); major site of digestion and absorption.

Duodenum

First 25 cm of small intestine; receives chyme, bile, and pancreatic juice.

Jejunum

Middle section of small intestine where most nutrient absorption occurs.

Ileum

Distal portion of small intestine that joins the large intestine at the ileocecal valve.

Villi

Microscopic finger-like projections of intestinal mucosa that increase surface area for absorption.

Lacteal

Lymphatic capillary within a villus that absorbs fats and fat-soluble vitamins.

Large intestine (Colon)

Organ that reabsorbs water, forms feces, and houses gut bacteria.

Ileocecal valve

Sphincter controlling flow from ileum into cecum of large intestine.

Cecum

Pouch-like first part of large intestine that receives chyme from ileum.

Vermiform appendix

Narrow tube attached to cecum; may play immunologic role.

Bile

Greenish fluid made by liver, stored in gallbladder, that emulsifies fats for digestion.

Liver

Large gland that produces bile, regulates glucose, stores nutrients, detoxifies blood, and makes plasma proteins.

Gallbladder

Small sac under liver that stores and concentrates bile.

Pancreas

Gland that secretes digestive enzymes and bicarbonate into duodenum and hormones (insulin, glucagon) into blood.

Lipase

Pancreatic enzyme that breaks triglycerides into free fatty acids and glycerol.

Amylase

Carbohydrate-digesting enzyme; salivary and pancreatic forms hydrolyze starch to maltose.

Trypsin

Pancreatic protease that splits proteins into smaller peptides in the small intestine.

Secretin

Duodenal hormone that stimulates pancreatic bicarbonate secretion and inhibits gastric acid.

Cholecystokinin (CCK)

Duodenal hormone that triggers gallbladder contraction and pancreatic enzyme release, slowing gastric emptying.

Gastrin

Stomach hormone that increases gastric acid and motility.

Gastric-inhibitory peptide (GIP)

Duodenal hormone that slows gastric activity and stimulates insulin release.

Enteric nervous system (ENS)

Intrinsic nerve network in GI tract walls that coordinates local digestive functions.

Autonomic nervous system

Visceral motor system; parasympathetic division stimulates digestion, sympathetic division inhibits it.

Parasympathetic stimulation

Part of autonomic system that increases GI motility and secretions (“rest and digest”).

Sympathetic stimulation

Part of autonomic system that decreases GI activity during stress (“fight or flight”).

Peritonitis

Inflammation of the peritoneum, often due to organ rupture or infection.

Gingivitis

Inflammation and infection of the gums (gingiva).

Periodontitis

Advanced gum infection involving supporting bone and periodontal ligament.

Oral thrush

Fungal infection of mouth caused by Candida species.

Gastroesophageal reflux disease (GERD)

Chronic backflow of acidic stomach contents into esophagus, causing heartburn and damage.

Peptic ulcer

Erosion of stomach or duodenal mucosa by gastric acid and pepsin.

Crohn disease

Type of inflammatory bowel disease causing chronic inflammation of distal small intestine (and elsewhere).

Ulcerative colitis

Inflammatory bowel disease characterized by ulcers in colon and rectum lining.

Celiac disease

Autoimmune intolerance to gluten that damages intestinal villi and impairs nutrient absorption.

Irritable bowel syndrome (IBS)

Functional disorder with intestinal hypersensitivity causing pain, constipation and/or diarrhea.

Diverticulitis

Inflammation of intestinal diverticula, often producing pain and bleeding.

Cirrhosis

Chronic liver disease where functional hepatocytes are replaced by scar tissue.

Hepatitis

Inflammation of the liver, commonly caused by viral infection (types A, B, C, D, E).

Cholelithiasis (Gallstones)

Formation of solid stones in the gallbladder or bile ducts.

Cholecystitis

Inflammation of the gallbladder, usually due to gallstones blocking ducts.

Pancreatitis

Inflammation of the pancreas that may impair enzyme and hormone production.

Jaundice

Yellowing of skin and eyes caused by excess bilirubin due to liver or bile duct problems.

Ileus

Intestinal obstruction resulting from absence of normal peristaltic movement.