Our bodies are constantly
exposed to potentially harmful mircroorganisms. If we didn't have
ways of protecting ourselves against these invaders, we could become
sick or even die from the smallest infection.
Our immune system has both
external and internal means of keeping foreign invaders from
damaging our bodies.
In this Lesson, we'll explore
our body's nonspecific immune defenses. These defenses work against
all types of invaders, without targeting a specific type of