The autonomic nervous system (ANS) regulates the functions of our internal organs (the viscera) such as the heart, stomach and intestines.
The flu is contagious a day before and five days to a week after its onset. Young children, people over 65, those with compromised immune systems, and people with a terminal illness are at risk of death from the flu.
1 Swine flu is contagious about one day before symptoms develop to about five to seven days after symptoms develop; some patients may be contagious for a longer time span.  The disease lasts about three to seven days with more serious infections lasting about nine to 10 days.