Immunity: Inate vs. Adaptive
This lesson covers the distinction between the body's first line of defense, innate immunity, and the sophisticated, specific response of adaptive immunity.
Innate Immunity Basics
Innate immunity is our non-specific first defense, present at birth. It includes physical barriers like skin, chemical deterrents such as stomach acid, and immune cells like neutrophils.
Adaptive Immunity Introduction
Adaptive immunity develops after exposure to pathogens. It's characterized by specificity and memory. It involves lymphocytes like B cells and T cells, which recognize specific antigens.
Innate Immune Speed
Innate immunity acts immediately, with responses starting within minutes to hours. Surprisingly, it also influences adaptive immunity by presenting antigens to lymphocytes.
Memory: Adaptive's Edge
Adaptive immunity's unique feature is memory, which ensures quicker, stronger responses upon re-encountering pathogens. Vaccines work by harnessing this memory without causing the disease.
Innate's Pattern Recognition
Innate cells have pattern recognition receptors (PRRs) that detect pathogen-associated molecular patterns (PAMPs), which are shared by groups of pathogens, enabling a rapid response.
Adaptive Immune Tolerance
Adaptive immunity includes a key ability called 'immune tolerance,' preventing attacks on the body's own cells. This system can sometimes fail, leading to autoimmune diseases.
What defines innate immunity?
Specificity and memory
Non-specific, present at birth
Develops after exposure
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