Week 6 Flashcards
What is immunity?
The ability of an organism to resist infection
What are the 2 pronged defense systems the human body employs?
Innate immunity and adaptive immunity
What is innate immunity
The non inducible and pre existing ability of the body to recognize and destroy a broad range of pathogens or their products
What does innate immunity depend on?
Depending on the virulence of the pathogen, the infectious dose, and the immune competence of the individual, innate mechanisms alone may be insufficient to eliminate the pathogen
What is adaptive immunity?
The acquired ability to recognize and destroy a specific pathogen or its products
How long does it take for an innate response to develop?
Several hours
What does innate immunity NOT require?
Previous exposure to the pathogen
How are Eukaryotes functionally similar to innate immunity?
functionally similar pathogen recognition mechanisms that lead to rapid and effective host defences
example: Fruit flys and humans use immune cells that show structural and evolutionary homology
What does Innate immunity consist of?
a) A variety of physical and chemical barriers to infection
b) Largely dependent on the activity of phagocytes
What are phagocytes
Cells that ingest, kill and digest microbial pathogens
Examples of phagocytes?
Neutrophils
Macrophages
Dendritic cells
Eosinophils
What are some cells of the innate immune system?
Mast cells, basophils, NK cells
What do mast cells/basophils do?
trigger inflammation when activated
What do NK cells do?
identify and destroy infected host cells
What are antigens?
A particular strain of pathogen or type of foreign material
How long does an adaptive response take to develop?
Several days
What increases the strength of the adaptive response?
Increase in the number of antigen-reactive lymphocytes (highly specific)