Outcome 13 - Immune System Flashcards
What is immunity?
body defending against damage or disease
What are the two categories of immunity?
- innate immunity
- adaptive immunity
what are external barriers that make up the first lines of defence?
- physical: skin, mucous membrane, hair/cilia, saliva, urine
- chemical: sebum, lysozome, gastric juice, vaginal secretion
What are the internal barriers that make up the second line of defence?
- antimicrobial substances
- natural killer cells
- phagocytes
- inflammation
- fever
What type of lymphocyte is part of the second line of defense?
phagocytes - neutrophils, macrophages, dendritic cells
NK cells
what are the 5 steps of phagocytosis?
- chemotaxis
- adherence
- ingestion
- digestion
- killing
what does PRISH stand for?
Pain
Redness
Immobility
Swelling
Heat
what is the first step of inflammation?
vasodilation, and increase blood vessel permeability
what is the second step of inflammation?
emigration of phagocytes
what phagocytic cell usually travels first to site of infection?
neutrophils
what is the precursor cell of a macrophage?
monocytes (in blood)
macro - in tissue
how does a fever function as a line of defence?
in attempt to inhibit microbe growth and to increase metabolic activity to aid in repair and to increase the effect of interferons
what are the two characteristics of adaptive immunity?
- specific for a particular foreign molecule (antigen)
- acquires memory for previously encountered antigens (making the second response faster)
what types of lymphocytes are involved in adaptive immunity?
t and b cells
what is the stem cell that lymphocytes are derived from?
multipotent stem cells from red bone marrow
where do lymphocytes mature?
B cells mature in the RBM
T cells mature in the thymus
what type of lymphocyte is responsible for cell-mediated immune response?
cytotoxic T cells (CD8 T cells)
what type of lymphocyte is responsible for antibody-mediated immune response?
B cells
what are the two types of T cells?
cytotoxic T cells (CD8 T cells + helper T cells (CD4 T cells)
memory T cells in lymphatic tissue
what type of adaptive immunity is effective against INTRACELLULAR pathogens?
cell-mediated immunity
what type of adaptive immunity is effective against EXTRACELLULAR pathogens?
antibody-mediated immunity
It is common for an antigen to provoke both the cell-mediated and antibody-mediated immune responses. t/f
true
Upon first encounter with an antigen, there is a large group of lymphocytes that have the correct antigen receptor. t/f
false
only a small group does
What is clonal selection?
creation of more t and B cells that have the correct antigen receptors
what are the two major categories of cells produced during clonal selection?
- effector cells
- memory cells
what is an antigen?
substance that is foreign and provokes an immune response
ANTIbody GENerator
what part of the antigen provokes an immune response?
the epitope
what are our self-antigens?
MHC antigens (multi-histocompatibility complex)
which type of lymphocyte leaves lymph tissue in the case of antigenic invasion?
cytotoxic t effector cells
what type of lymphocyte needs the antigen to be presented to them for activation?
T cells
what is the importance of t helper cells?
secrete cytokine (local hormone) that helps the activation and speed up the clonal selection process
what type of cells secrete antibodies?
B cells
what class of antibody is the most abundant?
IgG
what class of antibody can cross the placenta and be transferred to the fetus?
IgG
what class of antibody can be transferred to the fetus via breast milk?
IgA
list 5 different actions that antibodies use to disable the antigen.
- neutralize antigen
- immobilize bacteria
- agglutination (clumping)
- activate complement
- enhance phagocytosis