Immune System Flashcards
Innate immunity
Nonspecific, always active
Specific immunity
Target a specific pathogen, slower
Defensins
Antibacterial enzymes on skin
Lysozymes are an antibacterial compound found in
Tears and saliva
B-cells mature in the
Bone marrow
T-cells mature in the
Thymus
Neutrophils, Eosinophils, and Basophils are
Granulocytes
Lymphocytes and monocytes are
Agranulocytes
Specific immune response can be divided into
Humoral immunity and cell-mediated immunity
Humoral immunity is driven by
B-cells and antibodies
Cell-mediated immunity is driven by
T-cells
Complement system
Various proteins in blood act as a nonspecific defense against bacteria, punch holes into bacteria
Classical pathway of complement system
Requires antibodies
Alternative pathway of complement system
Does not require antibodies
Macrophages: innate vs adaptive
Innate
Mast cell: innate vs adaptive
Innate
Granulocytes: innate vs adaptive
Innate
Dendritic cell: innate vs adaptive
Innate
Natural killer cells: innate vs adaptive
Innate
Macrophage
Engulfs and consumes pathogens
MHC class I
Protein produced within a cell is presented on the surface of the cell, allowing immune system to monitor health of the cell and detect if the cell has been infeceted with a virus or intracellular pathogen
MHC-I pathway is also called
Endogenous pathway
MHC class II
Antigen-presenting cells pick up, process, and present external pathogens to MHC 2 to activate immune system
Dendritic cells
Present antigens to adaptive immune cells
Basophils and mast cells release
Histamine in response to allergens
Eosinophils release
Histamine in response to allergens and parasitic infections
Neutrophils target
Bacteria
Natural killer cells destroy
Cells that do not present MHC e.g. virally infected/cancer cells
MHC-I is found in
All nucleated cells
What causes formation of pus during an infection?
Dead neutrophil collections
What holds heavy and light chains together in antibodies
Disulfide bridges and noncovalent interactions
Variable region in antibodies
Antigen-binding region that binds one specific antigen
Clonal selection in B cells
Only B-cells that can bind the antigen with high affinity survive
Upon exposure to an antigen, B-cells will develop into
Plasma cells and memory cells
Primary response
Plasma cells produce antibodies, memory B-cells stay in lymph node
Secondary response
Memory cells produce specific antibodies when same antigen is encountered
Positive selection of T cells
Only T cells that can respond to presentation of antigen on MHC will mature
Negative selection of T cells
T cells that attack self are destroyed
Helper T cells
CD4+, secrete lymphokines, activate B cells
CD4+ T cells respond to
MHC II, external antigens e.g. bacteria, fungi, parasites
CD8+ T cells respond to
MHC I, intracellular infections e.g. viral
Cytotoxic T cells
CD8+, directly kills infected cells by injecting toxic chemicals
Suppressor T cells
Suppress immune response once infection has been contained
Interferon
Produced by cells infected with viruses to prevent viral replication
Purpose of self-antigen
Signal to immune cells that the cell is not foreign
Autoimmunity
Immune cells attack cells expressing self-antigens
Spleen
B cell development
Thymus
T cell selection
Thoracic duct
Connects lympathic system to cardiovascular system
Lymph nodes cell interactions
Antigen-presenting cells and lymphocytes
Types of lymphocytes
T cell, B cell
Antibody reaction against pathogens
- Mark a pathogen by destruction by phagocytic cells
- Cause pathogens to clump together for phagocytosis
- Neutralize pathogen by preventing it from invade tissues