When this occurs, action potentials can still be elicited; however, the inward current is carried by Ca++ (slow inward channels) exclusively. These action potentials resemble those found in pacemaker cells in the SA node, and can sometimes display spontaneous depolarization and automaticity. This ...
Cardiac pacemaker cells of the sinoatrial node initiate each and every heartbeat. Compared with our understanding of the constituents of their electrical excitation, little is known about the metabolic underpinnings that drive the automaticity of pacemak
The sinoatrial node (SAN) is the normal pacemaker generating the regular, rhythmic contraction of the mammalian heart. Pacemaker activity of SAN cells is based on the diastolic depolarization, during which SAN cells depolarize spontaneously toward the action potential threshold. However, single SAN ...
The normal heart rhythm, known as sinus rhythm, originates in specialized cardiac cells, called pacemaker cells, in the sino-atrial (SA) or sinus node and has been defined as a sinus node rate of 60 to 100 beats/minute. Each heart beat or contraction is initiated by generation of an ...
Cardiac pacing That cell or a group of cells within the heart which initiates each contraction. Normally, the S-A node performs the function; but in arrhythmias, cells almost anywhere in the heart can assume the role of the dominant pacemaker ...
The other cells are then secondary and will fire in the event that those in the sinoatrial node fail to start the chain reaction. When both primary and secondary pacemaker cells fail to keep the heartbeat regular, an artificial pacemaker might be considered. Pacemaker cells in the brain have...
In most humans, the concentration ofpacemaker cellsin the sinoatrial (SA) node is the natural pacemaker, and the resultant rhythm is a sinus rhythm. En humanos la concentración decélulasdemarcapasosen el nódulo sinoatrial (SA por sus siglas en inglés) es el marcapasos natural, y el ritmo...
1.SportsOne who sets the pace in a race. Also calledpacer,pacesetter. 2.A leader in a field:the fashion house that is the pacemaker.Also calledpacesetter. 3. a.A part of the body, such as the mass of muscle fibers of the sinoatrial node, that sets the pace or rhythm of physiologica...
The other cells are then secondary and will fire in the event that those in the sinoatrial node fail to start the chain reaction. When both primary and secondary pacemaker cells fail to keep the heartbeat regular, an artificial pacemaker might be considered. Pacemaker cells in the brain have...
a leading instance in its field 同义词:pacesetter a specialized bit of heart tissue that controls the heartbeat 同义词:cardiac pacemakersinoatrial nodeSA node an implanted electronic device that takes over the function of the natural cardiac pacemaker ...