muscular hydrostat

A muscular hydrostat is a biological structure found in animals. It is used to manipulate items (including food) or to move its host about and consists mainly of muscles with no skeletal support. It performs its hydraulic movement without fluid in a separate compartment, as in a hydrostatic skeleton. The principle behind the hydrostatic skeleton is that water is effectively incompressible at physiological pressures. Thus, a fiber-wound chamber full of water will act as a constant-volume system. What makes the muscular hydrostat unique is that it relies on the same principle, but there is no water-filled cavity. Instead, the bulk of the organ is made up of muscle, which also has constant volume and is effectively incompressible, its main material being water. Thus, instead of a cylinder wrapped with muscle and connective tissue that changes its shape, a muscular hydrostat is a cylinder made of muscle.
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