The entire length of tube that extends from the mouth to the anus, including the esophagus, stomach, and small and large intestines. Nutrientspass through the alimentary canal to the stomach and small intestine, and waste materials from these nutrients (and from other sites in the body) pass from the small intestine to the colon (large intestine) and anus.
Organic compounds made of carbon, hydrogen, oxygen, nitrogen, and (in some cases) sulfur bonded in characteristic formations. Strings of amino acids make up proteins.
A yellowish or greenish digestive fluid excreted by the liver.
A term for a chewed mass of food making its way through the initial portions of the alimentary canal.
Naturally occurring compounds, consisting of carbon, hydrogen, and oxygen, whose primary function in the body is to supply energy. Included in the carbohydrate group aresugars, starches, cellulose, and various other substances.
A polysaccharide that is the principal material in the cell walls ofplants. Cellulose also is found in such natural fibers as cotton and is used as a raw material in manufacturing such products as paper.
The large intestine, through which waste materials pass on their way to excretion through the anus.
A substance in which atoms of more than one element are bonded chemically to one another.
A protein material that speeds up chemical reactions in the bodies of plants and animals.
Indigestible material in food that simply passes through the digestivesystem, assisting in the peristaltic action of the alimentary canal and in the processing of waste. Examples of fiber, also called bulk or roughage, include cellulose.
The stomach and intestines.
A cell or group of cells that filters material from the blood, processes that material, and secretes it either for use again in the body or to be eliminated as waste.
A type of sugar that occurs widely in nature. Glucose is the form in which animals usually receive carbohydrates.
A white polysaccharide that is the most common form in which carbohydrates are stored in animal tissues, particularly muscle and liver tissues.
A term that refers to all or part of the alimentary canal. Although the word is considered a bit crude in everyday life, physicians and biological scientists concerned with this part of the anatomy use itregularly.
An iron-containing pigment in red blood cells that is responsible for transporting oxygen to the tissues and removing carbon dioxide from them.
Fats and oils, which dissolve in oily or fatty substances but not in water-based liquids. In the body, lipids supply energy in slow-release doses, protect organs from shock and damage, and provide insulation for the body, for instance, from toxins.
The chemical process by which nutrients are broken down and converted into energy or used in the construction of new tissue or other material in the body.
Inorganic substances that, in a nutritional context, serve a function similar to that of vitamins. Minerals may include chemical elements, particularly metallic ones, such as calcium or iron, as well as some compounds.
A group of tissues and cells, organized into a particular structure, that performs a specific function within anorganism.
At one time, chemists used the term organic only in reference to living things. Now the word is applied to compounds containing carbon and hydrogen.
A series of involuntary muscle contractions that force bolus, and later waste, through the alimentary canal.
A complexsugar, in which the molecules are composed of many glucose subunits arranged in a chain. Polysaccharides can be broken down chemically to produce simple sugars, or monosaccharides.
Large molecules built from long chains of amino acids. Proteins serve the functions of promoting normal growth, repairing damaged tissue, contributing to the body's immune system, and making enzymes.
A general term for a muscle that surrounds and is able to control the size of a bodily opening.
A biological relationship in which (usually) two species live in close proximity to each other and interact regularly in such a way as to benefit one or both of the organisms.
A group of cells, along with the substances that join them, that forms part of the structural materials in plants oranimals.
Organic substances that, in extremely small quantities, are essential to the nutrition of most animals and some plants. In particular, vitamins work with enzymes in regulating metabolic processes; they do not in themselves provide energy, however, and thus vitamins alone do not qualify as a form of nutrition.
Comment about this article, ask questions, or add new information about this topic: