Microbiology and Immunology 2500A/B Lecture Notes - Lecture 2: Tight Junction, Adaptive Immune System, Opsonin

• School: Western University
• Department: Microbiology and Immunology
• Course: Microbiology and Immunology 2500A/B
• Professor: Kelly Summers

Document Summary

Innate immunity = first line of defense against a pathogen (i. e. as soon as you inhale a flu virus innate immune system responds to pathogen) constantly ready to destroy pathogen. It is very effective at stopping majority of pathogens at early stage. Inherited from parents born with innate defenses: well conserved in evolution, all humans have same defenses (nothing unique) Responds immediately to pathogen pathogen usually eliminated before symptoms arise. No memory = does not remember being exposed to the pathogen before: always the same immune response to identical pathogen with each exposure, i. e. non adaptive. Innate immune defenses: barriers = block pathogen entry into tissues, innate cells/soluble molecules = rapidly eliminate pathogens that manage to go past barriers into tissues. If innate immune system is unsuccessful, certain innate cells initiate the adaptive immune system to eliminate pathogen. Modes of pathogen entry into body: through nose, skin (through a cut), through mouth and into gi tract, through reproductive tract.