Millions of cells, protecting you
The immune system has several lines of defense against life-threatening infections.
Immunity starts at your skin, your body’s largest organ. Human skin contains a type of immune cell called a T-lymphocyte, or T-cell for short.
There are actually more T-cells on your skin than in your blood.
The mucus in your nose and nasal passages collect pathogens from entering your body.
More mucus lining the insides of your respiratory system (like your throat and lungs) also protect you from pathogens.
When the body detects an invading virus or other pathogen, it releases various types of cells, like T-cells, to attack the invader.
Another type of lymphocyte, called a B-cell, creates antibodies that can attach to a pathogen and disarm it.
Your innate immune system responds to any pathogen or threatening substance.
The adaptive immune system has a memory. It can reproduce antibodies it created to fight off a previous infection.
Some of our behaviors can affect our immune system. Drinking, for example, can hamper our bodies’ response to pathogens.
"After an episode of binge drinking, the ability of the innate immune system...to fight infections is reduced," says George Koob, director of the National Institute on Alcohol Abuse and Alcoholism.
And it’s generally accepted that plenty of sleep, exercise, and a balanced diet can keep your immune system healthy.