Synopsis by Alice Day
The mechanism that protects the human body against invasion from viral, microbial, bacterial, and parasitic agents is the immune system, and in Our Immune System, viewers learn how this complex defense works. When the body detects a foreign substance, such as a virus, it quickly goes to work to eliminate it before it can do further harm. Even after the harmful substance has begun making an individual sick, the immune system is still responsible for ridding the body of it. When an organ transplant is necessary, drugs must be taken to keep the immune system from rejecting it as a foreign object.