BIOL-UA 11 Chapter Notes -Hemolymph, Innate Immune System, Cell Membrane
Document Summary
Immune system - enables an animal to avoid or limit many infections. A foreign molecule or cell doesn"t have to be pathogenic to elicit an immune response. Innate immunity - a defense that is active immediately upon infection and is the same whether or not the pathogen has been encountered previously. Detection of nonself is accomplished by molecular recognition. Small preset group of receptor proteins bind to molecules or structures that are absent from animal bodies but common to a group of viruses, bacteria, or other microbes; binding activates internal defenses. Adaptive immunity - vertebrate defense; produces a vast arsenal of receptors, giving recognition and response great specificity. Enhanced by previous exposure to the infecting pathogen. Insects rely on their exoskeleton as first line of defense; chitin barrier is effective against most pathogens. Chitin-based barrier also found in the insect intestine, blocking food-borne pathogens. Lysozyme - enzyme that breaks down bacterial cell walls; protect insect digestive system.
