Ch 1 Intro to Immune System Flashcards
Immunology
Study of a host’s reactions to foreign substances introduced into the body
Antigens
Foreign substances that induce a host response (S. aureus, Group A Strep)
Immunity
condition of being resistant to infection
Edward Jenner
1700s, Smallpox vaccine from Cowpox
Dr. Louis Pasteur
1800s, Father of immunology, vaccines
Attenuation
Change, make pathogen less virulent through heat, ageing, or chemical means
Humoral Immunity
noncellular portions of blood (antibodies) neutralise toxins
Opsonins
humoral/circulating factors, coats bacteria and neutralises charge to become more susceptible to phagocytosis
Antibodies
serum proteins produced by B cells when exposed to a foreign substance and react specifically with it
Acute-phase reactants (APR)
serum factor (inflammation marker) that increases nonspecifically in any infection
Innate/Natural Immunity
individual’s ability to resist infection by means of normally present body functions, nonadaptive/nonspecific, same for all pathogens when exposed
Adaptive Immunity
characterised by specificity for each individual pathogen/microbial agent and ability to remember prior exposure
Marginating
50% of neutrophils in peripheral blood adhere to blood vessel walls, allows diapedesis
Diapedesis
movement through blood vessel walls from circulating blood
Chemotaxins
chemical messengers cause cells to migrate in particular direction for diapdesis
Alveolar macrophages, Kupffer cells, microglial cells, histiocytes
lungs, liver macrophage, brain macrophage, connective tissue macrophage
Macrophages
innate - phagocytosis/tumor/parasite, adaptive - present antigens to T cells
Mast cells
Skin/connective tissues, increase vascular permeability and blood flow, induce and maintain allergy, antigen presenting cell (APC), conduit between innate and adaptive, resemble basophils
Dendritic Cells
most potent phagocytic cell, most effective APC, captures antigen and travel to lymph node to present to T cell for adaptive immunity
Clusters of Differentiation (CD)
antibodies reacting similarly with standard cell lines
B Cells (humoral)
BM->secondary organs, possesses antibody receptors for specific antigens, IgM/IgD, CD19-21, 10-20% lymphocytes
Plasma Cells
Most fully differentiated B lymph, antibody production, BM/germinal centers in peripheral lymphoid organs/not in blood, abundant cytoplasmic Ig/no surface Ig
T cells
Produce cytokines to stimulate B cells, kill tumor/virus, regulate innate/adaptive response
Cell-mediated immunity
immune processes in which T cells have primary role (no antibodies)
Helper T Cell (Th)
CD4, help B cell antibody production, adaptive
Cytotoxic T Cell (Tc)
CD8, kill virally infected and tumor cells
Regulatory T Cell (Treg)
CD4, control actions of other T cells
Natural Killer Cell (Innate)
CD16/56, mature in BM, no antigen specific receptors/no myeloid and dendritic cell markers (Kill target cells with no former exposure)
Secondary lymphoid organs
lymphopoiesis occurs here, most contact with foreign antigens,
Thoracic duct
largest lymphatic vessel, empties to left subclavian vein
Periartierior lymphoid sheath PALS (Spleen)
Part of white pulp surround central arteries, T cells presented with antigens from dendritic cells
Primary follicles (Spleen/Lymph node)
contains B cells not yet stimulated by antigens, attached to PALS sheath
Marginal Zone (Spleen)
contains dendritic cells that trap antigens, surrounds PALS
Lymph nodes
central collecting point for lymph fluid (filtrate of blood)
Outer Cortex (Lymph node)
outermost layer, contains macrophages and B cells in primary follicles
Paracortex (Lymph node)
Mature/immature T cell area surrounding medulla
Inner Medulla (Lymph node)
contains plasma cells, some T/B/macrophages
Afferent Lymphatic Vessels
where lymphocytes and foreign antigens enter nodes
Secondary Follicles/Germinal Center (Lymph)
consists of antigen-stimulated proliferating B cells/interior of secondary follicle (B cell transformation)
Memory cells (Lymph)
ability for immune system to react quicker to past foreign antigens (develops into plasma cells), dormant B cell in germinal center
