Editing Muscular hydrostat (section)

===Bending===
The bending of a muscular hydrostat can occur in two ways, both of which require the use of [[antagonistic muscle]]s.<ref name=Kier&Smith1985 /> 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. To bend the hydrostat structure, the unilateral contraction of longitudinal muscle must be accompanied by contractile activity of transverse, radial, or circular muscles to maintain a constant diameter. 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. 

The bending of a muscular hydrostat is particularly important in animal [[tongue]]s. 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]].<ref name=Smith&Kier1989 />