What is the difference in function between the innate and adaptive immune systems?
Innate immunity is an inborn, phylogenetically conserved system that allows the host to rapidly respond to a pathogen within 20 to 30 minutes of exposure. This system is inflexible in that only specific pathogen features will result in a response. In contrast, adaptive immunity develops over 3 to 5 days following pathogen exposure. Yet, this system is flexible, allowing refinement of the lymphocytes’ abilities to target the pathogen.