diagnostic procedure of nervous system autonomic nervous system function evaluation 2025-06-01T10:55:43Z PMID:22371714 The autonomic nervous system is the part of the nervous system that is responsible for regulation and integration of internal organs’ functioning. Most of the tests are based on evaluation of the cardiovascular reflexes triggered by performing specific provocative manoeuvres. Stimuli that raise blood pressure, such as isometric exercise, cold pressor test or mental arithmetic, activate mainly sympathetic outflow. Moreover, blood pressure responses to orthostatic testing and Valsalva manoeuvre are in a large part a reflection of sympathetic activity. Changes in heart rate during orthostatic testing and Valsalva manoeuvre, as well as during deep breathing or diving reflex, reflect parasympathetic modulation.