Learn more about the fascinating functions of hydrodynamic mechanisms and hydraulics in nature.

Fascinating Hydrodynamic Mechanisms

Posted: December 16th, 2009 | Filed under: Hydrostatic skeleton | Tags: , , , , , , | 1 Comment »

Animals can also make elective use of a hydrostatic skeleton, its main advantage being that it can be created for as long as it is needed. When it is no longer required, the pressure in the system can be reduced so that nothing remains of the skeleton. True enough, the hydrostatic skeleton is not as reliable as a bone one, and, where the supports have to be permanent, the hydrostatic skeleton has given way to more rigid constructions. But for non-permanent skeletons hydraulics has proved more advantageous. Nature has applied this invention throughout the history of the evolution of the animal kingdom, right from the lowest creatures up to the most developed ones, man included. Cavernous bodies employing blood as the working fluid is a good example.

Hydrodynamic mechanisms are still more fascinating. These range from extremely primitive devices to rather sophisticated ones. The most primitive of them include the excretory siphon-tube in bivalve mollusks. These living crea­tures derive oxygen and food, microscopic organisms and particles of plant and animal matter from the surrounding water, which they suck into the mantle cavity. The water saturated with carbon dioxide and polluted with excretory products is ejected through a special siphon-tube. The mollusk, no doubt, wishes the waste material to be removed far away from its body so that it would not return into its mantle cavity. This explains why the excretory siphon-tube is rather long, though it has no special muscle and cannot stretch. When the shell is closed and water stops moving into the mantle cavity, the siphon-tube con­tracts, but as soon as the fluid resumes its flow, the siphon straightens and stretches.

The hydrodynamic (water-vascular) mechanisms in the spider’s legs are concerned with locomotion. These eight-legged creatures whose legs consist of six or seven segments flex them, like all animals do, by contracting certain specific muscles, but extend them by increasing pressure within the chitin-clad legs.


Similar To Hydrostatic Skeleton

Posted: December 14th, 2009 | Filed under: Hydrostatic skeleton | Tags: , , , , , | 1 Comment »

It was not very good to employ the cardiovascular system to perform secondary functions. But after the pumps and the communicating systems had been invented, nature took a profound interest in hydraulics. To begin with, it seems to have guessed that by forcing liquids into the cavities and interstitial spaces it could considerably contribute to the turgor of the tissue, i. e. impart to the tissue a certain degree of mechanical strength. This is but one step from the foundation of the hydrostatic skeleton.

It sounds funny, but man only began using similar constructions in the 20th century, and they are still not being used on a wide scale. The utilization of compressed air is particularly eflective. Picture in your mind’s eye a column of bulldozers and cross-country vehicles which force their way through the taiga to the projected construction site. Within a few hours the space for builders settlement is cleared. Then not very bulky packages are unloaded from the vehicles.

The pumping facilities are switched on, and about half an hour later a settlement of two-storey canvas houses with inflatable beams and supporting structures has sprung up in the place won from the taiga. Convenient and efficient, this time-saving method of construction is surprisingly reliable. Besides, these canvas houses can also be warm enough if their walls are also made inflatable from two or three layers of rubberized canvas.