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.
Experts agree that it's going to be a nasty flu season in the U.S. this year. According to Business Insider, you can spread the influenza virus to others even before you know you're sick. The flu lasts anywhere from 5-7 days to up to two weeks. Experts say you're most contagious in the first 2-3 days. Everyone is different, of course, but it's best to wait at least 24 hours after your fever breaks before returning to work or school.