Chapter 15: Immune Response and Defence Against Disease Flashcards
What is an antigen?
A large molecule, usually a protein or polysaccharide, that generates an immune response
What is a pattern recognition receptor?
A cell receptor that recognises molecular patterns commonly shared by a number of pathogens
What is a pathogen-associated molecular pattern (PAMP)?
A broad molecular pattern commonly shared by a number of pathogens
What is an epitope?
A small part of a larger molecule that binds to a receptor site and is antigenic
What is an innate immune response?
A non-specific response to pathogens that are not learned and does not have memory
What is an adaptive immune response?
An acquired immune response; after an initial response to a pathogen, the immune system creates a ‘memory’ that leads to an enhanced response to subsequent encounters with the same pathogen
What is callose?
A polysaccharide formed in plant cell walls in response to injury
What are defensins?
A small, antimicrobial peptide secreted by virtually all plants and animals
What is the complement system?
A number of small proteins found in the blood that, when activated, promote chemotaxis, cell lysis nd phagocytosis
What the first three lines of defemse in vertebrates immune system?
1st - effective surface barriers that reduce the chance of pathogens gaining entry
2nd - inflammation and the complement system (macrophages (innate immune response))
3rd - the adaptive immune response
Where are mucous memebranes present?
Vertebrate respiratory, gastrointestinal and reproductive tracts
How do cilia act as a defense against pathogens entering the body?
Another way to remove mucus is by beating the slender hair-like structures called cilia that line the respiratory tract
What is a lysozyme?
An antibacterial enzyme found in tears, saliva and other body fluids, breaks down the cell wall of certain types of bacteria ad causing them to burst (lyse)
What are macrophages?
A large white blood cell in tissues that phagocytoses pathogens
What are cytokines?
A small signalling molecules that coordinates inflammtion and immune responses, and that lukocytes use to communicate with one another; includes interleukins and interferons
What are mast cells?
A cell located in the tissues, which when activated releases granules containing histamine
What is histamine?
A chemical released by mast cells that increases blood flow and the permeability of capillaries, induces vasodilation
What are prostoglandins?
A group of lipids that can cause vasodilation, fever and pain
What is chemotaxis?
The movement of an organism or cell along a chemical concentration gradient either towards (positive chemotaxis) or away from (negative chemotaxis) the chemical stimulus
What are the two types of leukocytes?
Monocytes and neutrophils
What is a monocyte?
A white blood cell that circulates in the blood and matures when it moves from the blood into the tissues
What is a neutrophil?
A phagocytic leukocyte found in the blood and tissues
What is a phagocyte?
A cell that is capable of phagocytosis; includes macrophages and neutrophils
What is a phagosome?
A membrane-bound vesicle formed around a particle during phagocytosis
