the electrical impulse of the heart originates at the sinoatrial node.
the electrical impulse of the heart originates at the sinoatrial node.
where does the electrical impulse of the heart originate?
sinoatrial node
if embryonic heart cells are separated into a petri dish and kept alive, each is capable of generating its own electrical impulse followed by contraction. when two independently beating embryonic cardiac muscle cells are placed together, the cell with the higher inherent rate sets the pace, and the impulse spreads from the faster to the slower cell to trigger a contraction. as more cells are joined together, the fastest cell continues to assume control of the rate. a fully developed adult heart maintains the capability of generating its own electrical impulse, triggered by the fastest cells, as part of the cardiac conduction system. the components of the cardiac conduction system include the atrial and ventricular syncytium, the sinoatrial node, the atrioventricular node, the bundle of his (atrioventricular bundle), the bundle branches, and the purkinje cells.
cardiac physiology
the difference between sa node block and sa node suppression is that in sa node block an electrical impulse is generated by the sa node that doesn't make the atria contract. in sa node suppression, on the other hand, the sa node doesn't generate an electrical impulse because it is reset by the electrical impulse that enters the sa node.









































section::::types.:av nodal blocks.









































there are three basic types of av nodal block:









































bullet::::- first-degree av block









































bullet::::- second-degree av block









































bullet::::- type i second-degree av block (mobitz i), also known as wenckebach block
heart block