Muscular hydrostat

It is used to manipulate items (including food) or to move its host about and consists mainly of muscles with no skeletal support.

A more peripheral distribution is found in tetrapod tongues, octopus arms, nautilus tentacles, and elephant trunks.

A transverse arrangement involves sheets of muscle fibers running perpendicular to the long axis, usually alternating between horizontal and vertical orientations.

Helical or oblique fibers around the long axis are generally present in two layers with opposite chirality and wrap around the central core of musculature.

[3] The mechanisms of elongation, bending and torsion in muscular hydrostats all depend on constancy of volume to effect shape changes in the absence of stiff skeletal attachments.

From this, if a diameter decreases by 25%, the length will increase by approximately 80% which may produce a large amount of force depending on what the animal is trying to do.

[3] Therefore, contractions of muscles perpendicular to the long axis will cause a decrease in diameter while keeping a constant volume will elongate the organ length-wise.

[1] The unilateral contraction of a longitudinal muscle will produce little or no bending and will serve to increase the diameter of the muscular hydrostat because of the constant volume principle that must be met.

Bending of a muscular hydrostat can also occur by the contraction of transverse, radial, or circular muscles which decreases the diameter.

Bending is produced by longitudinal muscle activity which maintains a constant length on one side of the structure.

This motion provides the mechanism by which a snake flicks the air with its tongue to sense its surroundings, and it is also responsible for the complexities of human speech.

[3] Torsion is the twisting of a muscular hydrostat along its long axis and is produced by a helical or oblique arrangement of musculature[3] which have varying direction.

to develop robotic arms that are able to manipulate and handle various objects of different size, mass, surface texture and mechanical properties.