Digestive System and Nutrition Flashcards

Vocabulary flashcards based on Chapter 9: Digestive System and Nutrition covering GI tract structures, digestive processes, accessory organs, nutrients, and eating disorders.

Ingestion

The intake of food into the body via the mouth.

Secretion

The addition of fluids and digestive enzymes into the digestive tract.

Digestion

The mechanical or chemical breakdown of foods into their constituent subunits.

Movement

The process of propelling food along the gastrointestinal (GI) tract to facilitate digestive processes.

Absorption

The transport of digested nutrients across the gastrointestinal (GI) tract wall into the blood to be delivered to body cells.

Elimination

The removal of indigestible molecules and waste from the body via the anus.

Mucosa

The innermost layer of the gastrointestinal tract wall that secretes protective mucus and digestive enzymes.

Submucosa

The second layer of the gastrointestinal tract wall, made of loose connective tissue containing blood vessels, lymphatic vessels, and nerves.

Muscularis

The third layer of the gastrointestinal tract wall, containing two layers of smooth muscle that contract to move food along the GI tract.

Serosa

The thin, outermost tissue layer of the gastrointestinal tract wall that forms part of the visceral peritoneum.

Salivary amylase

An enzyme present in saliva secreted by the salivary glands that initiates carbohydrate digestion in the mouth.

Bolus

A rounded mass of chewed food produced by tongue manipulation and pushed into the pharynx for swallowing.

Pharynx

A muscular cavity positioned between the mouth and esophagus that serves as a shared passageway for food and air.

Esophagus

A long muscular tube that transports food from the pharynx to the stomach via peristaltic contractions.

Peristalsis

Rhythmic, wave-like contractions of smooth muscle that move food along the digestive tract.

Gastroesophageal reflux disease (GERD)

A chronic digestive condition characterized by stomach acid frequently backing up into the esophagus, causing persistent heartburn.

Epiglottis

A flap of tissue that covers the glottis and larynx during swallowing to direct food into the esophagus and prevent entry into the trachea.

Rugae

Deep, internal folds in the mucosal wall of the stomach that allow it to expand when filled with food.

Pepsin

A protein-digesting enzyme secreted in gastric juice that functions in the acidic environment of the stomach.

Helicobacter pylori

A bacterium capable of residing in the stomach's protective mucus layer that can cause gastric ulcers.

Chyme

A thick, semi-fluid mixture of partially digested food and gastric juice created in the stomach and passed to the small intestine.

Villi

Microscopic, finger-like projections lining the inner surface of the small intestine that greatly increase the surface area available for nutrient absorption.

Pancreas

A spongy, fish-shaped accessory gland located behind the stomach that produces digestive enzymes, bicarbonate, and hormones such as insulin.

Liver

A major metabolic organ located under the diaphragm that processes nutrients, produces bile, stores glycogen and iron, and detoxifies blood from the GI tract.

Gallbladder

A small accessory organ under the liver that stores and concentrates bile before releasing it into the small intestine to emulsify fats.

Hepatitis

Inflammation of the liver caused by viral infections (hepatitis viruses A, B, and C) that can result in liver damage or liver failure.

Cirrhosis

A chronic liver disease characterized by fatty degeneration and fibrous scarring, commonly seen in severe alcoholism and obesity.

Cecum

The blind-ended initial section of the large intestine, connected to the small intestine and bearing the vermiform appendix.

Body Mass Index (BMI)

A health metric calculating the proportion of weight relative to height to estimate total body fat and assess related disease risks.

Obesity

A condition characterized by excessive adipose accumulation defined by a Body Mass Index (BMI) $≥ 30$.

Gastroplasty

A surgical weight-loss procedure involving the stapling or partitioning of a section of the stomach to reduce its holding capacity.

Gastric bypass

A bariatric surgical procedure where a small stomach pouch is reconnected directly to the lower small intestine, bypassing most of the stomach and duodenum.

Gastric banding

A surgical procedure that places an adjustable band around the upper portion of the stomach to restrict food intake.

Liposuction

The surgical removal of subcutaneous fat tissue, typically recommended for non-obese individuals seeking localized fat reduction.

Nutrients

Essential components of food required by the body for energy production, tissue repair, and metabolic maintenance.

Complex carbohydrates

Polysaccharide-rich foods such as whole grains, legumes, nuts, and fruits that provide sustained energy along with vitamins, minerals, and fiber.

Glycemic index

A numerical ranking system that measures how rapidly a carbohydrate-containing food raises blood glucose levels after ingestion.

Essential amino acids

The $8$ amino acids that the body cannot synthesize on its own and must obtain directly through dietary sources.

Complete proteins

Dietary protein sources that contain all $8$ essential amino acids in adequate proportions, typically obtained from animal products or soy.

Incomplete proteins

Plant-derived protein sources (such as grains, legumes, and nuts) that lack one or more essential amino acids.

Essential fatty acids

Polyunsaturated fats, such as linoleic acid and linolenic acid, that are necessary for human health and must be ingested in the diet.

Low density lipoprotein (LDL)

Referred to as "bad" cholesterol; a lipoprotein transport molecule that carries cholesterol from the liver to peripheral tissue cells.

High density lipoprotein (HDL)

Referred to as "good" cholesterol; a lipoprotein that transports excess cholesterol from body tissues to the liver for excretion as bile salts.

Trans-fatty acids

Unsaturated fats created artificially via industrial hydrogenation that can inhibit the metabolic clearance of cholesterol from the blood.

Major minerals

Essential inorganic elements required by the human body in amounts where total body storage exceeds $5\,g$ (e.g., calcium, sodium).

Trace minerals

Inorganic nutrient elements present in the body in total quantities of less than $5\,g$ (e.g., iron, iodine).

Vitamins

Essential organic compounds required in tiny amounts for metabolic regulation and enzymatic helper functions that the body cannot synthesize sufficiently.

Antioxidants

Chemical substances (such as vitamins A, C, and E) that protect cellular structures and DNA by neutralizing free radicals.

Anorexia nervosa

An eating disorder characterized by extreme fear of gaining weight, leading to self-induced starvation and excess physical activity.

Bulimia nervosa

An eating disorder characterized by episodes of binge eating followed by compensatory purging behaviors such as vomiting or laxative use.

Binge-eating disorder

An eating disorder marked by uncontrollable overeating episodes without purging, frequently leading to obesity, guilt, and depression.

Muscle dysmorphia

A body image disorder where individuals perceive their bodies as insufficiently muscular, leading to compulsive bodybuilding and strict diets.