Role of the cardiac gap junctions in impulse propagation – with special reference to the transitional region between different heart tissues (part 12)
It is generally accepted that gap junctions play a role in electrical cell-to-cell coupling and in cell-to-cell impulse propagation. Thus, conductivity is influenced by electrical resistivity of the gap junctions. Electrical resistivity of the gap junction is dependent on the size or number of gap junction channels . That is, the smaller the size or the fewer in number, the higher the resistivity. Electrical activities can be synchronized by smooth current flow through the gap junctions.
It was previously reported that there are some transitional types of cells with different membrane properties between the central and the peripheral cells of the sinus node . However, there is no doubt that local currents flow through the gap junctions between these cells. The present study suggests that gap junctions in the transitional region between the sinus node and the atrial follower cells are smaller in size or fewer in number than those in the sinus node or those in the atrial cells, and that conduction is impaired most markedly in the transitional region between the sinus node and the atrial follower cells, less markedly within the sinus node and least markedly within the atrium. Thus, the transitional region may contribute to induction of supraventricular conduction disturbances in pathological conditions such as ischemia. Visit the best pharmacy giving you generic vardenafil online cialis professional and taking the best care of you.