Chapter 43 Key Terms Flashcards
agents that cause disease such as bacteria, viruses, fungi or others
pathogens
system that enables animals to avoid or limit many infections
immune system
two types of molecular recognition
innate immunity and adaptive immunity
a defense active immediately upon infection
innate immunity
a response activated after the innate response and develops more slowly
adaptive immunity
what kind of immunity are barrier defenses?
innate
enzyme that breaks down bacterial cell walls (defense of invertebrates)
lysozyme
major immune cells of insects
hemocytes
process of cells breaking down microorganisms
phagocytosis
transmembrane receptor activated by binding of recognition proteins to fungal cell wall molecules (invertebrates)
Toll
activate production and secretion of antimicrobial peptides that kill fungal cells (invertebrates)
Toll
innate defenses of vertebrates similar to invertebrates
barrier defenses, phagocytosis, and antimicrobial peptides
innate defenses unique to vertebrates
natural killer cells, interferons, inflammatory response
barrier defenses include:
skin and mucous membranes
how does the skin and digestive system defend against the growth of bacteria
low pH of skin
innate immune cells in mammals detect, devour, and destroy invading pathogens using ___________ to recognize groups of pathogens
TLRs (toll like receptors)
recognize fragments of molecules characteristic of a set of pathogens
toll like receptors (TLR)
two MAIN kinds of phagocytic cells
neutrophils and macrophages
engulf and destroy pathogens
phagocytic cells
phagocytic cells that circulate in the blood
neutrophils
phagocytic cells that migrate through the body or reside permanently in organs and tissues
macrophages
two ADDITIONAL types of phagocytic cells
dendritic cells and eosinophils
phagocytic cells that stimulate development of adaptive immunity
dendritic cells
phagocytic cells that discharge destructive enzymes against parasites
eosinophils
type of innate defense; these circulate the body and detect abnormal cells; release chemicals leading to cell death, inhibiting the spread of virally infected or cancerous cells
natural killer cells