Osmosis video - Innate immune system

The innate immune system is the first line of defense against invading pathogens. It's composed of a variety of cells and proteins that work together to detect and destroy harmful invaders.

The innate immune system is activated within minutes of exposure to a pathogen, and it responds rapidly and nonspecifically to any threat. Its main function is to halt the spread of infection until the adaptive immune system can come into play.