Urine formation by excretory organs, Biology

Assignment Help:

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.


Related Discussions:- Urine formation by excretory organs

Parthenocarpy, Parthenocarpy It is generally observed that the fruit d...

Parthenocarpy It is generally observed that the fruit develops after fertilization and it has fertile seeds inside it. However, this is not always so. Fruits of certain variet

Define oxidised starch, Oxidised starch Oxidised starch finds a number ...

Oxidised starch Oxidised starch finds a number of uses in the food industry where a neutral tasting, low viscosity 'body builder' is required as in lemon curd manufacture, in s

What do you mean by amphibians of the plant world, Q. Why can the bryophyte...

Q. Why can the bryophytes be considered the "amphibians of the plant world"? Like adult amphibians, the bryophytes live in the terrestrial environment but they depend on water

How is extracellular digestion related to cellular, How is extracellular di...

How is extracellular digestion related to cellular and tissue specialization? Several of specialized cells and tissues appeared with extracellular digestion to give enzymes and

Define the skin capillary fragility test, Define the Skin Capillary Fragili...

Define the Skin Capillary Fragility Test? One of the earliest signs of ascorbic acid deficiency is the fragility of the capillaries. Capillary fragility is measured by applyin

What are the etiological agents of malaria, What are the etiological agents...

What are the etiological agents of malaria? The etiological agents of malaria are protozoans of the genus Plasmodium. There are four dissimilar types of plasmodia that cause ma

Define disadvantages of using bacteria as source of protein, Define Disadva...

Define Disadvantages of using Bacteria as a source of protein? Disadvantages of using Bacteria as a source of protein are as follow: a) If the bacterial strain is very small

Managing diarrhoea in children, Q. Managing diarrhoea in children? Mana...

Q. Managing diarrhoea in children? Managing diarrhoea in children is of great concern. The guidelines for the same are as follows: 1. The first objective is to rehydrate the

Theory of natural selection, What key idea, contained in Malthus's essay on...

What key idea, contained in Malthus's essay on populations, helped Darwin formulate his theory of natural selection?

Balloon aortic valvuloplasty for aortic stenosis, Q. Balloon Aortic Valvulo...

Q. Balloon Aortic Valvuloplasty for aortic stenosis? This is the procedure of choice in children and young individuals where the valve is not calcified. In elderly patients wit

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd