Protonephridia - excretion, Biology

Protonephridia - Excretion

Protonephridia are more primitive and occur mainly in acoelomate and pseudocoelomates animals. An animal may have two or more extensively branched protonephridia, each internally terminating in several bulb-like structures called flame cells or flame bulbs. In the lumen of each flame cell is found a tuft of cilia.

905_Protonephridia - Excretion.png

Figure:  Excretory system of planarian

 

 

Flame cells are common in flatworms and nemertines. In some of the coelomate worms that have protonephridia (e.g., polychaetes), the flame bulbs are Excretory pore replaced by a solenocytes. The solenocytes have a single flagellum projecting into the lumen instead of the ciliary tuft as found in the flame cells. It has been suggested that the undulating movements of the ciliary tuft or flagellum generate sufficient negative pressure for filtration and the force required to propel the fluid through the tubules. Flame cell system functions in animals without a circulatory system and pick up substances only from the tissue fluids.

 

 

Posted Date: 1/16/2013 1:28:06 AM | Location : United States







Related Discussions:- Protonephridia - excretion, Assignment Help, Ask Question on Protonephridia - excretion, Get Answer, Expert's Help, Protonephridia - excretion Discussions

Write discussion on Protonephridia - excretion
Your posts are moderated
Related Questions
Starch exists in plants as insoluble starch granules in chloroplasts.  Each starch granule   holds   a   combination   of   two   polysaccharide    forms, amylopectin and amylose.


In ancient Greece the father of Medicine, Hypocrates, described a method of diagnosing diabetes mellitus by tasting the patient's urine. What is the physiological explanation for t

Sterility in Angiosperms Sterility in angiosperms may arise due to several causes. Either the anther may not be formed, or anthers are formed but meiosis may be abnormal. A

Define the Solar Concentration? As in food dehydration, one of the simplest methods of evaporating water is with solar energy. A typical example of this method is production a

Describe different animal groups a) Could  comprehensively  compare  and  contrast  the  behaviours  exhibited  by  social animals rather than describe different animal groups


What are autotrophic beings? What are heterotrophic beings? Autotrophic beings are those that can make their own food, i.e., that make organic material from inorganic compound

INTRODUCTIO N - Endocrinolog y - Study of endocrine glands, hormones and their effects. Thomas Addison - Father of endocrinology. Described hormonal disease in 1855 kn

Medical Management   In chronic  renal failure  there  is irreversible renal failure. The goals of medical management are:   To promote maximal  renal  function  To ma