Urine formation by excretory organs, Biology

Urine Formation by Excretory Organs

Urine formation by the excretory organs involves

  1. The movement of water (solvent)' and dissolved molecules of small size (solutes) from the  lumen of the excretory organ into the interstitial fluid and blood and
  2. Movement back across the plasma membranes of the intervening cells (cells of the renal organs and blood capillaries).

While a variety of renal organs are encountered in the animal kingdom, the principles of their function-are basically similar. In all cases, renal function involves the initial -appearance in the tubular lumen of a fluid called primary urine which is isosmotic to blood or body fluid from which it is derived. The composition and volume of the primary urine are later altered by the reabsorption of useful substances (e.g., glucose) into the blood and by the secretion of unwanted substances (e.g., urea) from the blood into the tubular fluid. Both reabsorption and secretion involve active transport. These modifications in the composition and volume of primary urine result in the formation of urine which is the fluid finally excreted from the body.

Posted Date: 1/16/2013 2:21:48 AM | Location : United States







Related Discussions:- Urine formation by excretory organs, Assignment Help, Ask Question on Urine formation by excretory organs, Get Answer, Expert's Help, Urine formation by excretory organs Discussions

Write discussion on Urine formation by excretory organs
Your posts are moderated
Related Questions
How dissimilar are intracellular and extracellular digestion? What is the evolutionary benefit of extracellular digestion? Intracellular digestion is that in which the breaking

Proto-oncogenes Proto-oncogenes are common genes present. In all organisms and emerge to be highly conserved in the course of evolution. They have been isolated in species ra

Bovine parainfluenza This virus belongs to the genus Respirovirus in the subfamily Paramyxovirinae of family Paramyxoviridae. It causes respiratory syndrome in cattle and shee

Define the term- Ultrafiltration Ultrafiltration occurs when the flow of a substance across a cell membrane is increased by a hydrostatic pressure. This process was initially b

In which period of life does the formation of gametes begin in women? The meiosis that forms female gametes begins in the cells of the ovarian follicles before birth. After the

Which of the below are skin receptors in humans which are sensitive to heat? Are they: a) End organs of Krause b) Meissner's corpuscles c) End organs of Ruffini d)

Q. What are some examples of migratory animals? Instance of the migratory animals are southern right whales from Antarctica, that procreate on the Brazilian coast; the migrator

Explain about the Salting - Methods of Food Processing? Salting: Salting, especially of meat, is an ancient preservation technique. Food is treated with salt or a strong salt s

Gill slits are the opening or the clefts between the gill arches in the fish. Water taken in by the mouth passes through the gill slits and bathes the gills. It also has rudimenta

what is working of heart