Digestive System Vocabulary

Vocabulary practice flashcards covering the anatomical structures, digestive secretions, functions, nerve supplies, and pathology of the gastrointestinal system.

Ingestion

The process of taking food into the alimentary canal.

Propulsion

The process of mixing and moving digested content forward into the stomach.

Peritoneum

The largest serous membrane forming a closed sac in the abdomen containing serous fluid; composed of parietal peritoneum lining the abdominal wall and visceral peritoneum covering organs.

Myenteric Plexus (Auerbach's Plexus)

A network of nerves situated between the inner circular and outer longitudinal smooth muscle layers of the alimentary canal that regulates muscular contractions.

Peristalsis

A series of automatic, wave-like smooth muscle contractions and relaxations that propel food, liquid, and waste through the digestive tract.

Submucosal Plexus (Meissner's Plexus)

A nerve plexus located within the submucosa layer of the alimentary canal wall.

Filiform Papillae

The smallest and most abundant papillae on the surface of the tongue; they are the only papillae that do not contain taste buds.

Circumvallate Papillae

Large papillae arranged in a "V" shape on the posterior surface of the tongue that contain taste buds.

Fungiform Papillae

Mushroom-shaped papillae scattered on the tongue that contain taste sensory receptors.

Deciduous Teeth

Also known as primary teeth; the first set of dentition in humans consisting of $20$ teeth ($10$ per jaw).

Parotid Gland

A main paired salivary gland located on the side of the face; its parotid duct opens into the vestibule at the level of the upper second molar.

Submandibular Gland

A main paired salivary gland located under the lower jaw whose duct opens into the floor of the mouth on each side of the lingual frenulum.

Sublingual Gland

A main paired salivary gland located beneath the floor of the mouth that empties via numerous small duct openings into the mouth floor.

Upper Esophageal Sphincter

Also called the crico-pharyngeal sphincter; prevents the inflow of air into the esophagus during inspiration and backflow of esophageal contents.

Lower Esophageal Sphincter

Also called the cardiac sphincter; prevents the reflux of acidic gastric contents back up into the esophagus.

Rugae

Folds of mucosa present on the internal lining of the stomach when it is empty.

Chyme

The semi-fluid acidic mass of partially digested food created by churning movements of stomach muscle layers.

Intrinsic Factor

A protein component of gastric juice secreted by stomach cells essential for the absorption of vitamin B12.

Cephalic Phase

The initial phase of gastric juice secretion initiated by the sight, smell, or taste of food before it reaches the stomach, mediated by reflex vagus nerve stimulation.

Gastric Phase

The phase of gastric secretion where gastrin released by enteroendocrine cells in the pylorus/duodenum circulates to stimulate further gastric gland secretions.

Intestinal Phase

The stage of gastric regulation where secretin and cholecystokinin (CCK) released by endocrine cells in the small intestine slow down gastric secretion and motility.

Hepatopancreatic Ampulla

A common structure formed by the junction of the bile duct and pancreatic duct that opens into the duodenum at the duodenal papilla.

Sphincter of Oddi

A ring of smooth muscle that guards the duodenal papilla controlling the release of bile and pancreatic secretions.

First Pass Metabolism

The process by which absorbed substances and drugs traveling via the portal vein are extensively metabolized in the liver before reaching systemic circulation.

Pudendal Nerve

The nerve that provides voluntary somatic control over the skeletal muscle of the external anal sphincter.

Gastrocolic Reflex

A stimulus-response mechanism where eating triggers a wave of strong mass movement peristalsis across the transverse colon.

Valsalva's Manoeuvre

Contraction of abdominal muscles accompanied by lowering of the diaphragm to increase intra-abdominal pressure during defecation.

Thrush (Oral Candidiasis)

An opportunistic fungal infection of the oral mucosa caused by Candida albicans, presenting as white patches on the tongue and mouth inner lining.

Angular Cheilitis

Painful cracks developing in tissue folds at the corners of the mouth caused by Candida albicans, Staphylococcus aureus, or vitamin B and iron deficiency.

Barrett's Oesophagus

A premalignant condition following chronic reflux oesophagitis where columnar cells replace the normal stratified squamous epithelium of the lower esophagus.

Oesophageal Varices

Dilated submucosal veins in the esophagus created when portal hypertension causes blood to be shunted into systemic anastomotic veins.

Typhoid Fever

An infection caused by Salmonella typhi via contaminated food or water, leading to alimentary mucosal inflammation, high fever, diarrhea, spleen enlargement, and red skin spots.

Cholera

An intestinal infection caused by Vibrio cholerae whose enterotoxin causes massive secretion of water and electrolytes, leading to severe dehydration and hypovolaemic shock.

Hernia

The protrusion of an organ or part of an organ through the wall or surrounding structures of the cavity in which it is normally contained.

Mumps

An acute viral inflammatory infection of the salivary glands, most commonly causing bilateral or unilateral swelling of the parotid glands.