Cardiac pacemaker and eventual action potential in contractile cells. Having cardiomyocytes connected via gap junctions allow all contractile cells of the heart to act in a coordinated fashion and contract as a unit. All the while being in sync with the pacemaker cells; this is the property that allows the pacemaker cells to control contraction in all other cardiomyocytes. Cells in the SA node spontaneously depolarize, ultimately resulting in contraction, approximately 100 times per minute. This native rate is constantly modified by the activity of sympathetic and parasympathetic nerve fibers via the autonomic nervous system, so that the average resting cardiac rate
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