Transverse tubules (T - tubules) are extensions of the cell membrane that penetrate into the centre of skeletal and cardiac muscle cells. With membranes that contain large concentrations of ion channels, transporters, and pumps, T - tubules permit rapid transmission of the action potential into the cell, and also play an important role in regulating cellular calcium concentration. Through these mechanisms, T - tubules allow heart muscle cells to contract more forcefully by synchronising calcium release throughout the cell. T - tubule structure may be affected by disease, potentially contributing to heart failure and arrhythmias. Although these structures were first seen in 1897, research into T - tubule biology is ongoing.
t or transverse tubules in skeletal muscle function to
permit rapid transmission of the action potential into the cell, and also play an important role in regulating cellular calcium concentration