Digestive System Chapter 23 Flashcards

Comprehensive vocabulary flashcards covering the anatomy, histology, hormonal regulation, and physiological processes of the human digestive system.

Alimentary Canal

Also known as the GI tract or digestive tract; the continuous tube from mouth to anus with the primary purpose of nourishment.

Accessory Organs

Organs that assist in digestion but are not part of the alimentary canal, including the teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

Myenteric plexus (plexus of Auerbach)

A part of the intrinsic innervation (Enteric Nervous System) that coordinates muscle action in the digestive tract.

Submucosal plexus (plexus of Meissner)

An intrinsic nerve network in the submucosa that regulates secretion.

Mucosa

The innermost layer of the digestive tract tissue, consisting of the epithelium, lamina propria, and muscularis mucosae.

Peritoneum

A double-layered serous membrane (Parietal and Visceral) that supports and covers abdominal organs, separated by the peritoneal cavity.

Retroperitoneal Organs

Organs located posterior to the peritoneum, including the kidneys, pancreas, duodenum, and the ascending and descending colon.

Bolus

The name given to food after it has been chewed and mixed with saliva in the mouth.

Deciduous Teeth

The first set of $20$ baby teeth that are later replaced by $32$ permanent teeth.

Deglutition

The medical term for swallowing, which takes approximately $4-8$ seconds for solid food and $1$ second for liquid.

Peristalsis

Waves of muscular contractions that move a bolus along the digestive tract.

Chyme

The mixture of food, stomach acid, and enzymes produced by the churning and chemical digestion in the stomach.

Rugae

Folds in the mucosal lining of the stomach that allow for expansion and help create chyme.

Intrinsic Factor

A substance secreted by the stomach that is required for the absorption of vitamin $B_{12}$ in the small intestine.

Segmentation

Mechanical digestion in the small intestine that involves separating, combining, and mixing chyme to facilitate digestion and absorption.

Villi

Finger-like projections in the mucosal lining of the small intestine that increase surface area for nutrient absorption.

Teniae Coli

Three bands of longitudinal smooth muscle in the muscularis layer of the large intestine.

Haustra

Small pouches in the large intestine formed by the tonic contractions of the teniae coli.

Bilirubin

A pigment produced from the breakdown of red blood cells, processed by the liver and excreted in bile.

Gastrin

A hormone that stimulates the release of gastric acid in the stomach.

Secretin

A hormone that stimulates the release of bicarbonate from the pancreas to neutralize acidic chyme.

CCK (Cholecystokinin)

A hormone that stimulates the secretion of pancreatic enzymes and the release of bile from the liver and gallbladder.

Micelle

A structure that encloses free fatty acids and monoglycerides to facilitate their absorption into intestinal epithelial cells.

Chylomicrons

Fatty globules combined with proteins in the Golgi apparatus that enter lacteals for transport through the lymphatic system.

Ferritin

A protein that binds and stores iron within intestinal epithelial cells if it is not immediately needed by the body.