Heart function is controlled by the brain’s autonomic nervous system (the parasympathetic and sympathetic branches ... sends signals to increase heart rate, the IcNS can make quick adjustments ...

Heart Rate Increase ... tract contracts less - rate of peristalsis decreases Smooth muscle of digestive tract contracts more - rate of peristalsis increases Sympathetic (fight or flight) Action ...

In contrast, heart rate variability measures the time between individual beats. This measure can provide insight into the maturation of the fetal autonomic nervous system, with greater variability ...

Research shows that classical music in the third trimester enhances fetal heart rate stability, potentially influencing neurodevelopment and movement patterns.