Echinoderms possess a unique water vascular or ambulacral ( appendages such as " tube feet ") system.

In the crinoids, the tube feet waft food particles captured on the radial limbs towards the central mouth ; in the asteroids, the same wafting motion is employed to move the animal across the ground.

Some burrowing sea stars poke their tube feet through the surface of the sand or mud above them into the water column and use them to attain oxygen from the water column.

Exchange of gases also takes place through tube feet.

Once a particle touches the arms of the creature, the tube feet act to swish it to the central mouth of the crinoid, where it is ingested, nutrients removed, and the remains egested through its anus to the underlying water column.

Other toothless breeds devour smaller organisms, which they may catch with their tube feet, whole.

The latter are seized and held by the tube feet ; sea stars then stiffen their legs, expanding the shell.

Defensive strategies employed include the presence of spines, toxins, which can be inherent or delivered through the tube feet, and the discharge of sticky entangling threads by sea cucumbers.

Like other echinoderms, they have fivefold symmetry ( called pentamerism ) and move by means of hundreds of tiny, transparent, adhesive " tube feet ".

Although many sea cucumbers have branched tentacles surrounding the oral opening, these have originated from modified tube feet and are not homologous to the arms of the crinoids, sea stars, and brittle stars.

In these urchins, the upper surface of the body is slightly domed, but the underside is flat, while the sides are devoid of tube feet.

Urchins have tube feet, which arise from the five ambulacral areas.

This water vascular system works through hydrolic pressure, allowing the Sea Urchin to pump water into and out of the tube feet, enabling it to locomote.

This area, called the peristome, also includes five pairs of modified tube feet and, in many species, five pairs of gills.

The coelomocytes are an essential part of blood clotting, but also collect waste products and actively remove them from the body through the gills and tube feet.

From the nerve ring, five nerves radiate underneath the radial canals of the water vascular system, and branch into numerous finer nerves to innervate the tube feet, spines, and pedicellariae.

Sea urchins have no visible eyes, legs, or means of propulsion, but can move freely over hard surfaces using adhesive tube feet, working in conjunction with the spines.

Image: Zeeegel3. jpg | Sea urchin test-each white band is the location of a row of tube feet ; each pair of white bands is called an ambulacrum.

Image: Seeigel-Saugfuesse ( Galicien2005 ). jpg | Sea urchins have adhesive tube feet.

The facility is 1 million square feet in area and will produce tube goods to service natural gas exploration in the Marcellus Formation, which is the largest gas field discovered in the past decade, estimated to provide enough natural gas to supply the United States for 100 years.

The two outer funnels, which were six feet and eight inches long, were made of paper and connected to a tube inserted in each ear.

Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface.

The tube feet extend through notches in these and are connected internally to the water vascular system.

This system has many projections called tube feet on the starfish's arms which function in locomotion and aid with feeding.

The tube feet, spines, and pedicellariae found on starfish are sensitive to touch, while eyespots on the ends of the rays are light-sensitive.

The fundamental bilateral body form is a tube with a hollow gut cavity running from the mouth to the anus, and a nerve cord with an enlargement ( a ganglion ) for each body segment, with an especially large ganglion at the front, called the brain.

Some aficionados who prefer class-A amplifiers also prefer the use of thermionic valve ( or " tube ") designs instead of transistors, especially in Single-ended triode output configurations for several claimed reasons:

It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode ray tube ( CRT ) and flat panel or projection displays using fixed-element arrays.

* A particle detector ( implemented through use of an Anton type 213 Geiger-Müller tube ) to measure lower radiation ( especially near Venus ), also known as the Iowa detector, as it was provided by the University of Iowa.

Usually this degree of bleeding is due to delay in diagnosis, but sometimes, especially if the implantation is in the proximal tube ( just before it enters the uterus ), it may invade into the nearby Sampson artery, causing heavy bleeding earlier than usual.

Circuit board degradation is often seen on inexpensive tube radios produced in the 1960s, especially around the hot output and rectifier tubes.

Fly fishing for pike is another recently developing way of catching these fish, and the float tube is now recognized as an especially suitable water craft for pike fly-fishing.

The lack of visible flames and relatively clean wood smoke produced lulled the emergency services into a false sense of security, especially as firemen had attended more than 400 similar tube fires over the previous three decades.

The triode vacuum tube also develops a " space charge " between the cathode and control grid, which reduces its gain, especially at low anode voltages.

The amount of squeeze applied to the tubing affects pumping performance and the tube life-more squeezing decreases the tubing life dramatically, while less squeezing can cause the pumped medium to slip back, especially in high pressure pumping, and decreases the efficiency of the pump dramatically and the high velocity of the slip back typically causes premature failure of the hose.

The ambulacral grooves bear four rows of tube feet but these are diminished in size or absent in some holothurians, especially on the dorsal surface.

A quick-and-dirty method for switching, especially for those using a flash camera for the main components, is to use the flash tube itself as a switch.

* Duncan's amp pages — All sorts of information, especially on tube guitar amplifiers.

This variation of crêpes – especially when they are curled up to form a tube, and finished with a topping of powdered sugar, whipped cream, or both – is called French pancakes.

The brain is small and simple in some species, such as the nematode worm, where the body plan is quite simple: a tube with a hollow gut cavity running from the mouth to the anus, and a nerve cord with an enlargement ( a ganglion ) for each body segment, with an especially large ganglion at the front, called the brain.

In the U. S., manufacturers and retailers are allowed to list the tube size, which is misleading and confusing to many customers, especially when comparing both CRT and LCD models together.

The main advantage of breech-loading is a reduction in reloading time-it is much quicker to load the projectile and charge into the breech than to force them down a long tube, especially when the tube has spiral ridges from rifling.

It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode ray tube ( CRT ), Flat panel display which includes Liquid crystal displays, or projection displays using fixed picture-element ( pixel ) arrays.

Flicker is a visible fading between cycles displayed on video displays, especially the refresh interval on cathode ray tube ( CRT ) based computer screens.

The vacuum that surrounds the outside of the tube greatly reduces convection and conduction heat loss to the outside, therefore achieving greater efficiency than flat-plate collectors, especially in colder conditions.

Surgical techniques, using a tube or catheter to drain fluid from the peritoneum, chest, or the pericardium around the heart, are often used in cases of severe blunt trauma to the chest or abdomen, especially when a person is experiencing early signs of shock.

The bombing of London during the war and especially the Blitz led to the use of many tube stations as air-raid shelters.

DIY is especially active in loudspeaker and in tube amplification.