The autonomic nervous system (ANS or visceral nervous system) is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils, micturition (urination), and sexual arousal. Whereas most of its actions are involuntary, some, such as breathing, work in tandem with the conscious mind.

So, Cam acupuncture modulate ANS function? Answer is yes. Let's see this research....

Primary dysmenorrhea is a common gynecological complaint among young women that is related to an autonomic nervous system (ANS) disturbance. Acupuncture is one of several therapeutic approaches for primary dysmenorrhea, since it can modulate ANS function.

To prove this treatment, Korean scientists have done a research about this.As we know,The heart rate variability (HRV) parameters such as high frequency (HF), low frequency (LF) and LF/HF ratio are generally accepted tools to assess ANS activity. Their experimental design was a crossover and patient-blinded procedure. All subjects participated in Sham (SA) and Real Acupuncture (RA) procedure, separated by one month. They found The RA induced a significant decrease in LF/HF ratio and a significant increase in the HF power, while SA treatment caused a significant increase only in the HF power. Manual acupuncture at bilateral acupoints of LI4 and SP6 may play a role in dysmenorrhea treatment with autonomic nervous system involvement.

So, Acupuncture definitely modulate ANS function.
Reference:Kim E, Cho JH, Jung WS, Lee S, Pak SC.Am J Chin Med. 2011;39(2):243-9.