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.
The estimated incubation period is unknown and could range from 1 to 7 days, and more likely 1 to 4 days. Persons with novel H1N1 flu virus infection should be considered potentially contagious (able to spread disease) for up to 7 days after illness onset. Persons who continue to be ill longer than 7 days should be considered potentially contagious until symptoms have resolved.