Circulation, respiration and excretion of asteroidea, Biology

Circulation, Respiration and Excretion of Asteroidea

Asteroids depend upon the circulation of coelomic fluid for the transport of gases and some nutrients. The blood vascular system termed as haemal system in echinoderms is not very well developed in asteroids. The channels lack a lining. Though, these channels are surrounded by extensions of coelom called perihaemal sinuses. There are four (4) coelomic circulatory systems in asteroids.

(1) The perivisceral coelom and the fluid that circulates in it that supplies the viscera

(2) The water vascular system which supplies the muscles of the tube feet that aids in locomotion

(3) Hyponeural sinus system which supplies the nervous system

(4) Genital coelom that supplies the genital organs.

Echinoderms live completely in sea water with which their body fluid is isotonic. The nitrogenous excretory wastes are removed through the thin areas of body surface, such as tube feet and papulae by diffusion. Besides, coelomocytes as well play a role in removing the metabolic wastes from the coelom. Gas exchange in asteroids is achieved by papulae (dermal branchiae), soft projections of coelomic cavity standing out by the spaces between ossicles. Tube feet are also principal respiratory organs.

Posted Date: 2/4/2013 1:17:12 AM | Location : United States







Related Discussions:- Circulation, respiration and excretion of asteroidea, Assignment Help, Ask Question on Circulation, respiration and excretion of asteroidea, Get Answer, Expert's Help, Circulation, respiration and excretion of asteroidea Discussions

Write discussion on Circulation, respiration and excretion of asteroidea
Your posts are moderated
Related Questions
What is Subphylum Vertebrata explain? This large group of animals takes its name from its distinguishing feature: the vertebral column, or the backbone. The backbone made of se

Stabilized forms of natural colourants The mimicking of the native environment in which a natural colour exists is just one way of producing a stabilized form. In this case, th

A virus capsid containing vimentin, your protein of interest, gets into the cell nucleus and is broken down with the DNA being released. It is unknown whether the capsids themselve

Which functional group (side-chain) can be "cross-linked" in protein? a. sulfhydryl b. amino c. Phosphate d. Hydroxyl e. Carboxyl


Define Diagnostic Criteria for Anorexia Nervosa? Table gives the American Psychiatric Association diagnostic criteria for anorexia nervosa. Although the manual does not use bod

Explain about the Solar Dryers? There are so many different designs for solar dryers, these range from simple convection dryers, cabinet dryers, shelf dryers to more complicate

Triglyceride accumulation is not a feature of the atherosclerotic plaque but triglyceride-rich lipoproteins also contain cholesterol esters and it is likely that some of these are

Law of Diminishing Return A German scientist Mitscherlich calculated the effect of different quantities of various growth factors on the yield of plants by means of a mathemat

Define Primary Level Care - Public Nutrition? This is the first level of contact of an individual, the family and the community with the national health system. It is possible