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 CDC explains that even healthy-looking people can spread the flu, as most individuals become contagious before they start showing flu symptoms. Flu-infected individuals are usually contagious for at least a week, though children can be contagious for more than a week. During this time, those infected with the flu must minimize contact with others, stay home, and avoid sharing bedding, food, utensils, clothing and other household objects with others.