Hydrostatic skeleton, Biology

Assignment Help:

Hydrostatic Skeleton

The functioning of the hydrostatic skeleton in an animal depends upon the musculature being arranged around an enclosed volume of fluid. After that, contraction of some of the muscles can cause pressure on the fluid that can be transmitted to the rest of the body, in all directions. In annelids, the coelom with the fluid in the coelomic space (or spaces) together along with the surrounding musculature constitute the hydrostatic skeleton. The coelomic fluid has a constant volume. Commonly speaking, contraction of any muscle in the body wall of an annelid would cause an increase in the hydrostatic pressure that in turn would cause stretching of flaccid muscles. In annelids along with circular and longitudinal 'muscles, contraction of one set of muscles is accompanied through stretching of the other. Polychaetes have feebly developed body musculature. The spacious coelom is compartmentalized through transverse septa. Though, there are perforations in the transverse septa which allow continuity of the coelomic fluid among compartments. So in polychaetes the hydrostatic skeleton is not well developed. In oligochaetes, the body musculature is very well developed and the transverse septa do not have the perforations during locomotion. The coelom in the adjoining segments stays mostly isolated. Like the longitudinal muscles of a segment contract, the circular muscles relax and owing to the incompressibility of the coelomic fluid, the segment turns shorter but thicker. Simultaneous protrusion of the setae helps the worm anchor to the substratum. While the reverse happens, that is, when the circular muscles contract, the longitudinal muscles relax, the segments become long and thin, the setae are withdrawn and the body progress forward. That is, the contraction and relaxation activities are localized being limited to a few segments of the body, the wave of contraction and relaxation passing from one end to the other. This results in the animal's progression.


Related Discussions:- Hydrostatic skeleton

What is aneuploidy, What is aneuploidy? What are the conditions caused by t...

What is aneuploidy? What are the conditions caused by the aneuploidies? The Aneuploidy is an abnormal number of chromosomes in the cells of an individual. The major aneuploi

Electron transport inhibitors, Electron Transport Inhibitors Several  c...

Electron Transport Inhibitors Several  compounds, including specific drugs, chemicals  and antibiotics  have been known to inhibit the electron  transfer  reactions at specific

Final energetic products of every round of the krebs cycle, Q. What are the...

Q. What are the final energetic products of every round of the Krebs cycle? And Where is most part of the utile energy at the end of Krebs cycle found? After each round of the

Why on earth would be drinking milk to feel better, If a person has a stoma...

If a person has a stomach ulcer (that is aggravated by excessive hydrochloric acid {HCl} secretion ), why on earth would he or she be drinking milk to feel better, when milk is als

PHYLUM ANNELIDA, GERENAL CHARACTERICS OF PHYLUM ANNELIDA

GERENAL CHARACTERICS OF PHYLUM ANNELIDA

What do you mean by oxalates, Q. What do you mean by Oxalates? Oxalates...

Q. What do you mean by Oxalates? Oxalates are widely distributed in plant foods mostly in the form of calcium salts. Oxalates are known to interfere with calcium absorpti

Difference between temporal summation and spatial summation, Q. What is the...

Q. What is the difference between temporal summation and spatial summation of muscle fibers? What is tetany?   Spatial summation is the recruiting of new muscle fibers to incr

Mycotoxins, Fungi are a very diverse group of organisms and have a signific...

Fungi are a very diverse group of organisms and have a significant impact on the production, spoilage and safety of food. Molds have not only served to synthesize antibiotics but a

Elimination of the risk factors - diabetes mellitus, Q. Elimination of the ...

Q. Elimination of the risk factors - diabetes mellitus? In other words, in diabetes it refers to maintaining of normal body weight, healthy nutritional practice, regular physic

Production efficiency - ecosystem, Production Efficiency - Ecosystem T...

Production Efficiency - Ecosystem The maximum amount of solar energy harvested by plants is about 5 per cent but the average for green plants, on the whole is only a small fra

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