Digestive System Basics & Organs -P1

A set of vocabulary flashcards covering the key structures, functions, and processes of the digestive system, as outlined in the lecture notes.

Digestive System

Body system responsible for converting food into absorbable nutrients and eliminating wastes.

Ingestion

The act of taking food or liquid into the mouth.

Secretion (Digestive)

Release of water, enzymes, acids, and buffers into the gastrointestinal (GI) tract.

Mechanical Digestion

Physical breakdown of food by chewing, mixing, churning, or other movements.

Chemical Digestion

Enzymatic breakdown of food molecules through hydrolysis.

Peristalsis

Rhythmic, wave-like contractions of GI tract muscles that propel food forward.

Segmentation

Back-and-forth muscular movements that mix chyme with digestive juices and enhance contact with the intestinal wall.

Absorption

Passage of digested nutrients from the GI tract into the blood or lymph.

Defecation

Elimination of indigestible substances and wastes from the body as feces.

Alimentary Canal (GI Tract)

Continuous muscular tube comprising mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.

Accessory Digestive Organs

Structures that aid digestion but are not part of the GI tract; include liver, gallbladder, pancreas, teeth, tongue, and salivary glands.

Mucosa

Innermost layer of the GI tract that secretes mucus, absorbs nutrients, and houses immune tissue.

Submucosa

Connective-tissue layer of the GI tract containing blood vessels, nerves, and the submucosal plexus.

Muscularis

Layer of smooth (and some skeletal) muscle in the GI tract responsible for peristalsis and segmentation; contains the myenteric plexus.

Serosa

Slippery outermost covering of intraperitoneal GI organs; forms part of the visceral peritoneum.

Adventitia

Fibrous connective-tissue covering that anchors retroperitoneal structures such as the esophagus.

Nonkeratinized Stratified Squamous Epithelium

Protective lining found in the mouth, pharynx, esophagus, and anus.

Simple Columnar Epithelium

Absorptive and secretory lining found in the stomach and intestines.

MALT (Mucosa-Associated Lymphatic Tissue)

Immune clusters in the mucosa that guard the GI tract against pathogens.

Muscularis Mucosae

Thin layer of smooth muscle in the mucosa that forms folds to increase digestive surface area.

Submucosal Plexus

Network of nerves in the submucosa that controls glandular secretions of the GI tract.

Myenteric Plexus

Nerve network between muscularis layers that regulates GI motility.

Skeletal Muscle in GI Tract

Voluntary muscle found in the mouth, pharynx, upper esophagus, and external anal sphincter.