Cardiac pacemaker ventricles, within the atrial septum. If the AV node also fails, Purkinje fibers are occasionally capable of acting as the default or "escape" pacemaker. The reason Purkinje cells do not normally control the heart rate is that they generate action potentials at a lower frequency than the AV or SA nodes. Cardiac pacemaker The contraction of cardiac muscle (heart muscle) in all animals is initiated by electrical impulses known as action potentials. The rate at which these impulses fire controls the rate of cardiac contraction, that is, the heart rate. The cells that create these rhythmic impulses, setting the pace
Cardiac neural crest cells secondary heart field cells into the cardiac outflow tract. FGF8 mouse mutants have a range of cardiac defects including underdeveloped arch arteries and transposition of the great arteries. GATA transcription factors, which are complex molecules that bind to the DNA sequence "GATA", play a critical role in cell lineage differentiation restriction during cardiac development. The primary function of GATA6 in cardiovascular development is to regulate the morphogenetic patterning of the outflow tract and aortic arch. When GATA6 is inactivated in CNCCs, various cardiovascular defects such as persistent truncus arteriorus and interrupted aortic arch may occur. This phenotype (anomaly) was also