Heart arrhythmia muscle cell firing off an impulse on its own. All of the cells in the heart have the ability to initiate an action potential; however, only some of these cells are designed to routinely trigger heart beats. These cells are found in the conduction system of the heart and include the SA node, AV node, Bundle of His and Purkinje fibers. The sinoatrial node is a single specialized location in the atrium that has a higher automaticity (a faster pacemaker) than the rest of the heart and, therefore, is usually responsible for setting the heart rate and initiating each heart
Cardiac neural crest cells OFT defects. Canonical Wnt signaling is especially important for cell cycle regulation of CNCC development and the initiation of CNCC migration. Non-canonical Wnt signaling plays a greater role in promoting cardiac differentiation and OFT development. Notch is a transmembrane protein whose signaling is required for differentiation of CNCCs to vascular smooth muscle cells and for proliferation of cardiac myocytes (muscle cells of the heart). In mice, disruption of Notch signaling results in aortic arch branching defects and pulmonary stenosis, as well as a defect in the development of the smooth muscle cells of the sixth aortic arch artery, which is