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.
How Long Is the Flu Contagious? A 2013 survey conducted by the National Foundation for Infectious Diseases revealed that 41 percent of people think the flu is only contagious after symptoms start. Thatâs not true. An adult infected with influenza may be contagious from one day before symptoms start until five to seven days after becoming sick.