The link between heartrate variability and autonomic nervous system function So, how does the heart give an insight into the workings of the autonomic nervous system? This is made possible because the activity of the heart is influenced by the ANS. The ANS is divided into two branches; the sympathetic nervous program and the parasympathetic anxious system . The sympathetic nervous system activates the ‘fight-or-flight’ response when confronted with stressful circumstances or perceived danger.Or sufferers with high amounts who do not react to standard treatment could possibly be treated with additional therapy rapidly. The researchers also discovered that bone marrow transplant sufferers with high degrees of elafin were much more likely to die of GVHD than people who have low levels. That details also could information treatment choices. A strategy to evaluate treatment plans is badly required because transplant sufferers today often require a lot more than 20 different medications a time, many with very critical unwanted effects.