Navigation Links
Excretion


Excretion is the biological process by which an organism separates waste products from its body. The waste products are then usually expelled from the body by elimination.

In mammals, for example, the two major excretory processes are the formation of urine in the kidneys and the formation of feces in the intestines. The waste products are eliminated by urination and defecation respectively.

While urine and feces are both waste material of body processes, they are in completely different categories. Urine is a waste product of the urinary system process while feces are waste products of the digestive system. Feces may contain about one-third bacteria, most of which are harmless, even beneficial while in the gut, but dangerous to others and they may also contain virulent and even deadly pathogens in the form of bacteria, viruses, amoebae, and various parasitic worms. Urine, on the other hand, contains excess water, salt, and protein waste in the form of urea as uric acid, and seldom any pathogens; should a person be in a situation of insufficient water and in danger of overheating due to lack of persperation, urine may be safely used to dampen clothing to aid cooling. It is futile to attempt to drink it (or salty ocean water), as it requires more water from the body to excrete the salt than is available in the fluid. Some sea birds are able to efficently excrete excess salt through the tear ducts associated with the eyes. Such birds can drink sea water without harm.

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 stuffs.

See also


'"/>


(Date:7/9/2015)... , July 9, 2015  Synaptics Inc. ... of human interface solutions, today announced a ... first fully hardware encapsulated fingerprint sensor and ... technology is literally off the grid, isolating ... matching within the fingerprint sensor to provide ...
(Date:7/8/2015)... DIEGO , July 8, 2015  Trovagene, ... cell-free molecular diagnostics, today announced the launch of ... the Company,s Precision Cancer Monitoring℠ (PCM) technology for ... receiving one or a combination of the novel ... Opdivo® (nivolumab), a PD-1 inhibitor. The 50-patient study ...
(Date:7/7/2015)... , July 7, 2015  Based on its ... & Sullivan recognizes Credence ID, LLC with the ... Company of the Year Award. Credence ID has ... in its mission of offering enrollment and identification ... As Credence ID was formed by experts from ...
Breaking Biology News(10 mins):Synaptics Announces World's First Match-in-Sensor Fingerprint Authentication Technology 2Synaptics Announces World's First Match-in-Sensor Fingerprint Authentication Technology 3Trovagene Initiates Study to Monitor Response to Immunotherapy in Melanoma Patients Using its Precision Cancer Monitoring Platform 2Trovagene Initiates Study to Monitor Response to Immunotherapy in Melanoma Patients Using its Precision Cancer Monitoring Platform 3Trovagene Initiates Study to Monitor Response to Immunotherapy in Melanoma Patients Using its Precision Cancer Monitoring Platform 4Frost & Sullivan Acknowledges the Distinctive Customer-focused Attributes of Credence ID's Mobile Biometric Product Suite 2Frost & Sullivan Acknowledges the Distinctive Customer-focused Attributes of Credence ID's Mobile Biometric Product Suite 3Frost & Sullivan Acknowledges the Distinctive Customer-focused Attributes of Credence ID's Mobile Biometric Product Suite 4Frost & Sullivan Acknowledges the Distinctive Customer-focused Attributes of Credence ID's Mobile Biometric Product Suite 5
... Two USC scientists have developed an algorithm that could help ... be useful to researchers of all stripes. Andrew Smith, ... Arts and Sciences, developed the algorithm along with USC graduate ... more DNA, to be published in Nature Methods ...
... found a new way to accelerate a workhorse instrument that ... and point to new drugs for treating a wide range ... used in muscle, brain, blood and hormones. If the genes ... hammers and tongs of life. Proteins are not only ...
... articles posted online ahead of print on 20 Feb. 2013 ... on the Exmouth Sub-basin, Australia; the West Kunlun Range, northern ... hot springs of Colorado. The 12 new papers cover a ... to Earth,s surface, A challenge to climate change and biotic ...
Cached Biology News:Taking the gamble out of DNA sequencing 2Analytical trick accelerates protein studies 2Analytical trick accelerates protein studies 3Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 2Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 3Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 4Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 5Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 6Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 7Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 8Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 9Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 10Color in fossil insects, diamonds from the ancient ocean floor and modeling the world's largest rivers 11
Other biology definitionOther Tags