1.the bodily process of discharging waste matter
2.waste matter (as urine or sweat but especially feces) discharged from the body
ExcretionEx*cre"tion (?), n. [Cf. F. excrétion.]
1. The act of excreting.
To promote secretion and excretion. Pereira.
2. That which is excreted; excrement. Bacon.
definition of Wikipedia
substance d'origine animale (fr)[ClasseParExt.]
liquide organique (fr)[Classe]
fait de.. (fr)[Classe...]
liquide organique (fr)[Thème]
anatomie du corps humain (fr)[DomainDescrip.]
answer the call of nature[ClasseParExt.]
discharge, eject, exhaust, expel, release - passage, passing - elimination, evacuation, excreting, excretion, voiding - excretory - emptying, evacuation, voidance - defecator, shitter, voider - cathartic, evacuant, purgative[Dérivé]
discharge, emission, expelling[Hyper.]
substance d'origine animale (fr)[ClasseParExt.]
résidu d'origine animale (fr)[Classe]
remains; remain; rest[Classe]
(answer the call of nature)[Thème]
Excretion is the process by which waste products of metabolism and other non-useful materials are eliminated from an organism. This is primarily carried out by the lungs, kidneys and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell. Excretion is an essential process in all forms of life.
In single-celled organisms, waste products are discharged directly through the surface of the cell. Multicellular organisms utilize more complex excretory methods. Higher plants eliminate gases through the stomata, or pores, on the surface of leaves. Animals have special excretory organs.
In plants, breakdown of substances is much slower than in animals. Hence accumulation of waste is much slower and there are no special organs of excretion. Green plants in darkness or plants that do not contain chlorophyll produce carbon dioxide and water as respiratory waste products. Carbon dioxide released during respiration gets utilized during photosynthesis. Oxygen itself can be thought of as a waste product generated during photosynthesis, and exits through stomata, root cell walls, and other routes. Plants can get rid of excess water by transpiration and guttation. Waste products may be stored in leaves that fall off. Other waste materials that are exuded by some plants — resins, saps, latexes, etc. are forced from the interior of the plant by hydrostatic pressures inside the plant and by absorptive forces of plant cells. These processes do not need added energy, they act passively. Plants also excrete some waste substances into the soil around them.
Aquatic animals usually excrete ammonia directly into the external environment, as this compound has high solubility and there is ample water available for dilution. In terrestrial animals ammonia-like compounds are converted into other nitrogenous materials as there is less water in the environment and ammonia itself is toxic.
Birds excrete their nitrogenous wastes as uric acid in the form of a paste. This is metabolically more expensive, but allows more efficient water retention and it can be stored more easily in the egg. Many avian species, especially seabirds, can also excrete salt via specialized nasal salt glands, the saline solution leaving through nostrils in the beak.
In insects, a system involving Malpighian tubules is utilized to excrete metabolic waste. Metabolic waste diffuses or is actively transported into the tubule, which transports the wastes to the intestines. The metabolic waste is then released from the body along with fecal matter.
|Wikimedia Commons has media related to: Excretion|
|Look up excretion in Wiktionary, the free dictionary.|
Dictionary and translator for handheld
New : sensagent is now available on your handheld
A windows (pop-into) of information (full-content of Sensagent) triggered by double-clicking any word on your webpage. Give contextual explanation and translation from your sites !
With a SensagentBox, visitors to your site can access reliable information on over 5 million pages provided by Sensagent.com. Choose the design that fits your site.
Improve your site content
Add new content to your site from Sensagent by XML.
Crawl products or adds
Get XML access to reach the best products.
Index images and define metadata
Get XML access to fix the meaning of your metadata.
Please, email us to describe your idea.
Lettris is a curious tetris-clone game where all the bricks have the same square shape but different content. Each square carries a letter. To make squares disappear and save space for other squares you have to assemble English words (left, right, up, down) from the falling squares.
Boggle gives you 3 minutes to find as many words (3 letters or more) as you can in a grid of 16 letters. You can also try the grid of 16 letters. Letters must be adjacent and longer words score better. See if you can get into the grid Hall of Fame !
Change the target language to find translations.
Tips: browse the semantic fields (see From ideas to words) in two languages to learn more.