Nutrition, Digestion, and Absorption Vocabulary

Comprehensive vocabulary flashcards generated from introductory nutrition, digestion, absorption, and food safety lecture topics.

Nutrition

The science of foods, their nutrients, and other substances they contain, including their ingestion, digestion, absorption, transport, metabolism, interaction, storage, and excretion.

Nutrients

Substances obtained from food and used in the body to provide energy and structural materials, and to serve as regulating agents to promote growth, maintenance, and repair.

Dietary Pattern

The combination of foods and beverages that constitute an individual's complete dietary intake over time.

Chronic Diseases

Diseases characterized by slow progression, long duration, and degeneration of body organs that have complex causes.

Risk Factor

A personal characteristic, such as family history, age, environmental conditions, or lifestyle, that increases your chances of developing a chronic disease.

Metabolism

The total of all chemical reactions that occur within cells.

Organic Nutrients

Substances containing carbon-carbon or carbon-hydrogen bonds, specifically carbohydrates, lipids, proteins, and vitamins.

Inorganic Nutrients

Substances not containing carbon or pertaining to living organisms, specifically minerals and water.

Macronutrients

The energy-yielding nutrients required by the body in large amounts, comprising carbohydrates, proteins, and fats.

Micronutrients

Nutrients required by the body in very small amounts, specifically vitamins and minerals, which help facilitate energy release.

Kilocalorie (kcal)

The amount of heat energy necessary to raise the temperature of $1\,kg$ of water by $1\,^\circ\text{C}$, equal to $1000\,calories$.

Energy Density

A measure of the energy a food provides relative to the amount or weight of the food, expressed as $kcal/g$.

Essential Nutrients

Nutrients that a person must obtain from food because the body cannot make them for itself in sufficient quantities to meet physiological needs.

Phytochemicals

Non-nutrient compounds produced by plants that exhibit biological activity in the body and contribute to plant aroma, color, and flavor.

Antioxidants

Substances that protect cells and cellular components from damage caused by exposure to harmful environmental and internal factors.

Malnutrition

Any condition caused by deficient or excess energy or nutrient intake, or by an imbalance of nutrients.

Nutrient Density

A measure of the nutrients a food provides relative to the energy (calories) it yields.

Empty Kcalories

Kcalories provided by added sugars and solid fats that deliver few or no other nutrients.

Whole Grain Kernel

A grain kernel containing the bran, endosperm, and germ.

Daily Values (DV)

Reference values developed by the FDA specifically for use on food labels to compare the nutrient content within a serving to recommended amounts.

Nutrient Claims

Statements on food package labels that characterize the quantity of a nutrient in a food.

Health Claims

Statements on food labels that characterize the relationship between a nutrient or other substance in food and a disease or health-related condition.

Structure-Function Claims

Statements on food labels describing how a product or nutrient may affect a structure or function of the human body.

Dietary Reference Intakes (DRI)

A set of values for the dietary nutrient intakes of healthy people in the United States and Canada.

Estimated Average Requirement (EAR)

The average daily nutrient intake level estimated to meet the requirements of $50\%$ of healthy individuals in a specific sex and age group.

Recommended Dietary Allowance (RDA)

The average daily nutrient intake level considered adequate to meet the known nutrient needs of practically all ($98\%$) healthy people in a sex and age group.

Tolerable Upper Intake Level (UL)

The highest average daily nutrient intake level likely to pose no risk of toxicity to most healthy people.

Acceptable Macronutrient Distribution Ranges (AMDR)

Ranges of intakes for energy-yielding nutrients that provide adequate energy and reduce chronic disease risk: Carbohydrates ($45\text{--}65\%$), Protein ($10\text{--}35\%$), and Fat ($20\text{--}35\%$).

Double-Blind Study

An experimental study in which neither the researchers nor the participants are aware of each participant's group assignment.

Placebo Effect

A change in health or feeling that occurs in response to receiving a fake or sham treatment.

Quackery

Anything involving over-promotion in the field of health, including questionable ideas, products, and services.

Registered Dietitian (RD / RDN)

A college-trained, certified or registered health care professional specializing in food and nutrition.

Mechanical Digestion

The physical breakdown of food into smaller pieces by chewing, churning, and segmentation to increase surface area for enzymes.

Chemical Digestion

The breakdown of food molecules into their chemical building blocks by digestive enzymes and acids.

Gastrointestinal (GI) Tract

The flexible, muscular tube extending from the mouth to the anus that digests food and absorbs nutrients.

Salivary Amylase

The principal salivary enzyme that begins breaking down amylose (starch) into smaller sugar molecules in the mouth.

Bolus

The soft, moist mass of food formed in the mouth after chewing and mixing with saliva.

Epiglottis

A structure that closes over the trachea during swallowing to prevent food from entering the larynx and lungs.

Peristalsis

Involuntary, wave-like muscle contractions that propel food and chyme forward through the digestive tract.

Lower Gastroesophageal Sphincter (LES)

A muscular ring at the junction of the esophagus and stomach that opens to let food enter and closes to prevent stomach acid reflux.

Gastric Juice

An acidic digestive secretion produced by gastric glands containing water, hydrochloric acid ($\text{HCl}$), pepsin, and mucus.

Chyme

A semi-liquid mixture of partially digested food and gastric juices formed in the stomach.

Pyloric Sphincter

A circular muscle sphincter between the stomach and small intestine that regulates the release of chyme into the duodenum.

Enteric Nervous System (ENS)

A network of nerves within the GI tract that regulates peristalsis and the secretion of digestive juices.

Enterogastrone

Any gastrointestinal hormone that slows motility and inhibits gastric secretions.

Gastrin

A hormone secreted by cells in the stomach wall that stimulates gastric acid ($\text{HCl}$) secretion.

Secretin

A hormone secreted by the duodenum in response to acidic chyme that stimulates the pancreas to release bicarbonate.

Cholecystokinin (CCK)

A hormone secreted by the small intestine that stimulates the release of bile from the gallbladder and digestive enzymes from the pancreas.

Villi

Fingerlike projections on the mucosal folds of the small intestine that increase surface area for nutrient absorption.

Microvilli

Tiny, hairlike projections on each epithelial cell of every villus that trap nutrient particles for transport into cells.

Segmentation

Alternating contractions of circular intestinal muscles that mix chyme with digestive juices and bring nutrients into contact with the wall.

Chylomicrons

Lipoprotein particles formed in intestinal cells that transport absorbed dietary fats and fat-soluble vitamins through the lymphatic system.

Lacteals

Lymphatic vessels inside intestinal villi that absorb large lipid molecules and chylomicrons.

Hepatic Portal Vein

A major blood vessel that gathers water-soluble nutrients absorbed from the GI tract and delivers them directly to the liver.

Bile

A substance manufactured by the liver and stored in the gallbladder that emulsifies fats to aid in fat digestion.

Prebiotics

Indigestible substances in foods, such as fibers, that stimulate the growth of beneficial gut bacteria.

Probiotics

Live microorganisms found in foods and supplements that confer health benefits when consumed in sufficient quantities.

GERD (Gastroesophageal Reflux Disease)

A disorder characterized by frequent and severe acid reflux or heartburn.

Celiac Disease

An autoimmune response in the small intestine triggered by gluten that leads to the destruction of intestinal villi.

Cross-Contamination

The contamination of food by bacteria occurring when food comes into contact with surfaces previously touched by raw meat, poultry, or seafood.

Temperature Danger Zone (TDZ)

The temperature range between $40\,^\circ\text{F}$ and $140\,^\circ\text{F}$ in which foodborne pathogens grow rapidly.