when was the link between muscular contraction and electricity discovered
Muscle contraction In 1780, Luigi Galvani discovered that the muscles of dead frogs' legs twitched when struck by an electrical spark.[39] This was one of the first forays into the study of bioelectricity, a field that still studies the electrical patterns and signals in tissues such as nerves and muscles.
Cardiac physiology It is not very well known how the electric signal moves in the atria. It seems that it moves in a radial way, but Bachmann's bundle and coronary sinus muscle play a role in conduction between the two atria, which have a nearly simultaneous systole.[5][6][7] While in the ventricles, the signal is carried by specialized tissue called the Purkinje fibers which then transmit the electric charge to the myocardium.[8]