Sinoatrial block Sinoatrial block A sinoatrial block is a disorder in the normal rhythm of the heart, known as a heart block, that is initiated in the sinoatrial node. The initial action impulse in a heart is usually formed in the sinoatrial node (SA node) and carried through the atria, down the internodal atrial pathways to the atrioventricular node (AV) node. In normal conduction, the impulse would travel across the bundle of His (AV bundle), down the bundle branches, and into the Purkinje fibers. This would depolarize the ventricles and cause them to contract. In an SA block, the electrical impulse is
Node-to-node data transfer Node-to-node data transfer In telecommunications, node-to-node data transfer is the movement of data from one node of a network to the next. In the OSI model it is handled by the lowest two layers, the data link layer and the physical layer. In most communication systems, the transmitting point applies source coding, followed by channel coding, and lastly, line coding. This produces the baseband signal. The presence of filters may perform pulse shaping. Some systems then use modulation to multiplex many baseband signals into a broadband signal. The receiver un-does these transformations in reverse order: demodulation, trellis decoding, error detection