Definitions

Nutrition = the series of chemical, biochemical, & physiological processes which transform food elements into body tissues and activities

Nutrient = any chemical substance that can be used and is necessary for the maintenance, production and health of animals

Digestion = the combination of mechanical, chemical and enzymatic processes occurring in the gastrointestinal tract (GI) that prepares ingested material for absorption by reducing particle size and increasing solubility

Absorption = the passage or movement of the end products of digestion (nutrients) through the wall of the GI tract to the general circulation (blood)

Distribution = movement of nutrients from the absorptive sites to the various cells in the body via blood stream

Metabolism = sum of all physical and chemical processes by which living, organized substance is produced and maintained

Anabolism = any constructive process by which simple substances are converted by living cells to more complex compounds

Catabolism = any destructive process by which complex substances are converted by living cells to more simple compounds

Excretion = the removal from the body of unusable materials and waste products of metabolism