the immune system Flashcards
what are the 2 types of immunity that are immune system consists of?
-innate immunity
-adaptive immunity
what is innate immunity? what are the 2 types of responses?
non-specific and fast response:
-barriers (physical and chemical)
-internal defenses
in innate immunity, what are the different types of internal defences?
-recognition of traits shared by broad ranges of pathogens, using a small set of receptors
-white blood cells (phagocytic and non-phagocytic)
-antimicrobial peptides
-inflammatory responses
-rapid response
what is adaptive immunity?
acquired immunity
-specific and slower response
-humoral and cell-mediated response
-recognition of traits specific to particular pathogens, using a vast array of receptors
who has innate immunity?
all animals
who has acquired immunity?
vertebrates
what are innate immunity barrier defences?
-skin
-mucous membranes
-secretions
what are innate immunity internal defences?
-phagocytic cells
-natural killer cells
-antimicrobial proteins
-inflammatory response
in adaptive immunity what is humoral response?
-antibodies defend against infection in body fluids
in adaptive immunity what is cell-mediated response?
cytotoxic cells defend against infection in body cells
in innate immunity, what is the first line of defence?
Physical and chemical barriers.
what are examples of physics; and chemical barriers?
-skin, mucous membranes (lining of digestive, respiratory and genitourinary tract)
-sweat contains acids that inhibit bacterial growth
-saliva, tears and mucous wash away pathogens and contain lysozyme to destroy bacterial cell wall
what is the second line of defence of innate immunity?
inflammatory response
what happens during inflammatory response? When does it happen?
-when tissue is damaged or microorganisms enter (or both)
-damaged cells or microorganisms release chemicals that:
increase permeability and blood flow
bring clotting factors and phagocytic cells to the cite
what are the chemicals released by the damaged cells during the inflammatory response? what do they allow for?
-histimines
-cytokines
-prostaglandins
these chemicals allow for the increase of blood flow to site, dilating blood vessels and increasing permeability of capillaries
what are phagocytic white blood cells?
white blood cells that ingest invading microbes
what are the types of phagocytic blood cells?
1) neutrophils
2) macrophages
how do phagocytic white blood cells kill pathogens?
what are the non-phagocytic white blood cells? what do they each do?
1) eosinophils: release chemicals to destroy parasites
2) mast cells: release histamine
3) natural killer cells: destroy virus-infected cells and cancer cells by causing cell lysis
what chemicals kill the cell by cell lysis?
perforin and granzyme
what are the two types of antimicrobial peptides?
1) complement
2) interferon
what are complement antimicrobial peptides?
-over 30 serum proteins
-involved in a cascade of steps which lead to cell lysis of a bacterium or an infected cell
what does an interferon do?
-secreted by virus infected cells
-prevents cell-cell spread of the virus and inhibits viral production
-like an alarm
how are interferons made?
they are secreted by viral cells
how do interferons prevent the spread of virus?
what are the key players in the adaptive/acquired immunity system?
antigens
antibodies
lymphocytes
antigen presenting cells
what are the 2 types of lymphocytes?
-B-cells
-T-cells (T-helper cells and cytotoxic T-cells)
what are the types of antigen presenting cells?
-macropages
-dendritic cells
-B-cells
which antigen presenting cell is present in both immune systems?
macrophages
what are antigens?
-protein or a polysaccharide that lymphocytes are reactive to
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how do antigens work?
-each antigen has a unique structure that a specific T-cell or B-cell receptor will bind to
-antigens are found on the surface of viruses, virus-infected cells, bacteria, fungi, protozoa, pollen or transplanted tissue
what do lymphocytes do?
mediate cell response
what do B-cells do?
-involved in humoral response
-produce antibodies
-mature in the bone marrow
what do T-cells do?
-involved in cell mediated response
-mature in the thymus
what do mature T-cells and B-cells have on their surfaces?
antigen receptors
what are the 2 types of B-cells?
-plasma cell
-memory B-cell
what’s a plasma cell?
effector B-cells that produce antibodies
what’s a memory B-cell?
-long lived and will act in future infections
-has antigen receptor
what is the antibody structure?
-compromised of 4 polypeptide chains (2 identical light chains, 2 identical heavy chains)
-each chain is composed of a variable region and a constant region
what is the variable chain of the antibody?
-amino acid sequence varies from antibody to antibody
-binds to specific antigen