Heart rate node, where the faster pacemaker cells driving the self-generated rhythmic firing and responsible for the heart's autorhythmicity are located. For endurance athletes at the elite level, it is not unusual to have a resting heart rate between 33 and 50 bpm. The "maximum heart rate" (HR) is the highest heart rate an individual can achieve without severe problems through exercise stress, and generally decreases with age. Since HR varies by individual, the most accurate way of measuring any single person's HR is via a cardiac stress test. In this test, a person is subjected to controlled physiologic stress (generally by
Cardiac neural crest cells of differentiated cells such as neurons, glial cells, pigment-containing cells in skin, skeletal tissue cells in the head, and many more. Cardiac neural crest cells (CNCCs) are a type of neural crest cells that migrate to the circumpharyngeal ridge (an arc-shape ridge above the pharyngeal arches) and then into the 3rd, 4th and 6th pharyngeal arches and the cardiac outflow tract (OFT). They extend from the otic placodes (the structure in developing embryos that will later form the ears) to the third somites (clusters of mesoderm that will become skeletal muscle, vertebrae and dermis). The cardiac neural crest cells have