Chapter 43 - The Immune System Flashcards
What are pathogens?
agents that cause disease
What is innate immunity?
a defense all animals have that is active immediately upon infection
What is adaptive immunity?
a defense vertebrates have that is activated after the innate response and develops more slowly, but uses a vast array of receptors
What is a lysozyme?
an enzyme that breaks down bacterial cell walls; part of the innate immunity of invertebrates
What is phagocytosis?
the ingestion and digestion of foreign substances
What do hemocytes do?
secrete antimicrobial peptides that disrupt the plasma membranes of fungi and bacteria
What are barrier defenses?
defenses in the innate immunity response that include the skin and mucous membranes of the respiratory, urinary, and reproductive tracts
What do toll-like receptors (TLRs) in mammals do?
recognize fragments of molecules characteristic of a set of pathogens
Name the 4 kinds of phagocytic cells?
neutrophils, macrophages, dendritic cells, and eosinophils
Where are neutrophils?
circulating in the blood
Where are macrophages?
migrating through the body or residing permanently in organs and tissues
What do dendritic cells do?
stimulate the development of adaptive immunity
What do eosinophils do?
discharge destructive enzymes against parasites
