Digestive System Part 1 Vocabulary

Vocabulary flashcards covering the components, functions, metabolic processes, chemical breakdown products, and mucosa layers of the Digestive System Part 1.

Gastrointestinal Tract (GI Tract)

Also known as the alimentary canal; continuous tube containing organs including the mouth, pharynx, esophagus, stomach, small intestine, and large intestine.

Accessory Digestive Organs

Organs including the teeth, tongue, salivary glands, liver, gallbladder, and pancreas that aid in the physical or chemical breakdown of food.

Ingestion

The taking of food or liquid into the mouth.

Secretion

The release of water, acid, buffers, and enzymes into the lumen of the GI tract.

Mixing and Propulsion

Alternating contractions and relaxations of smooth muscle in the walls of the GI tract that mix food and secretions and move them towards the anus.

Digestion

Mechanical and chemical processes that break down ingested food into small molecules.

Absorption

The movement of digested products from the GI tract into the blood and lymph.

Defecation

The process of getting rid of indigestible substances from the GI tract.

Mechanical Digestion

All movements and physical actions—such as teeth cutting/grinding food or smooth muscles in the stomach and small intestine churning food—that facilitate catabolic processes.

Chemical Digestion

The process of splitting large carbohydrate, lipid, protein, and nucleic acid molecules into smaller molecules using water to break chemical bonds (hydrolysis).

Catabolism

Metabolic process of breaking down larger molecules into smaller molecules; occurs in the mouth, stomach, and duodenum.

Anabolism

Metabolic process of assembling smaller building blocks into larger molecules.

Mastication

The mechanical process of chewing, cutting, and grinding food with teeth before swallowing.

Peristalsis

Smooth muscle movement in the GI tract that facilitates the forward propulsion of food.

Hydrolysis

The chemical process of using water to break chemical bonds during digestion.

Monosaccharides

The simplest form of carbohydrates, produced when polysaccharides are broken down during chemical digestion.

Triglycerides

Fats that are chemically broken down into fatty acids (FA) and glycerol during digestion.

Nucleotides

The breakdown products of nucleic acids, composed of a sugar, phosphates, and nitrogenous bases.

GI Tract Tissue Layers (Deep to Superficial)

The four-layer arrangement of tissues from lower esophagus to anal canal: 1. Mucosa, 2. Submucosa, 3. Muscularis (2 layers), 4. Serosa.

Mucosa

The inner lining of the GI tract, consisting of three layers: Epithelium, Lamina Propria, and Muscularis Mucosae.

Epithelium (Mucosa)

The innermost layer of mucosa made of protective non-keratinized stratified squamous cells in the mouth, pharynx, and esophagus, and simple columnar cells lining the stomach and intestines for secretion and absorption.

Lamina Propria

Areolar connective tissue layer of the mucosa that supports the epithelium, binds it to the muscularis mucosae, and contains the majority of MALT cells.

MALT (Mucosa-Associated Lymphatic Tissue)

Lymphatic tissue consisting of lymphocytes (T and B cells), antibody-releasing plasma cells, and macrophages located along the GI tract, especially in tonsils, small intestine, appendix, and colon.

Muscularis Mucosae

A thin layer of smooth muscle fibers in the mucosa that produces folds in the stomach and small intestine to increase surface area for digestion and absorption.