Part 10/14:
In muscle fibers, this electrical activity triggers calcium release, enabling contraction.
Muscle Movement in Invertebrates: The Case of Worms and Mollusks
In invertebrates such as earthworms and mollusks, muscle contraction involves simple, coordinated interactions of circular and longitudinal muscles:
These animals rely on hydrostatic skeletons supported by fluid-filled cavities called the coelom.
Circular and longitudinal muscles contract reciprocally, producing wave-like movements for crawling.
Such movements rely on cycles of contraction and relaxation, driven by neural signals and the pressure of coelomic fluid.
For worms like earthworms, movement is achieved through peristaltic waves, with muscles contracting sequentially to propel the organism over surfaces.