Muscular tissue

Tissue formed of cells, able to quickly contract repeatedly.

Muscular cells are able to contract due to special fibrous proteins, which move along each other consuming chemical energy (ATP). These proteins are more or less disordered in muscular cells responsible for involuntary movements e.g. in the wall of blood vessels (smooth muscular cells, as shown by the figure). The fibres are more or less ordered in muscular cells responsible for voluntary movements, which results in a striated appearance of the muscles under the microscope.