chapter 23 - introduction to immunology: the war against microbes Flashcards
what is immunity?
resistance to infection, or invasion by virus, bacteria, fungi, or protozoan
immunity can be…
specific or nonspecific
what is included in the innate nonspecific immune system?
first + second line of defense
dendritic cells defintion
pt 1 of process
like intelligence specialists.. collect pieces of the invader at the site and then travel to the nearest lymph node, presenting the piece of invader to the t cells
t cells definition
pt 2 of process
like system communication specialist… t cells then activate b cells to train them to form antibodies, the molecular weapons that target the invader specifically
b cells definition
pt 3 of process
b cells release millions of antibodies that are tailored to bind and neutralize enemies. the immune system deploys these until the enemy is wiped out
first line of defense
contains structures like the skin, bacteriostats or fluids, cilia, and mucus membranes
second line of defense
a. )cell mediated phagocytic cells like macrophages surround and destroy foreign matter
b. )inflammation - response to tissue damage which causes redness, swelling, and warmth due to increase in cells and fluids. white blood cells rush to sit
c. )fever
how do fevers work?
once bacteria is recognized, the lymphocytes release pyrogens to tell the brain to raise body temp
elevated body temp creates favorable environment for microbial growth and enhances normal immune response
third line of defense (specific)
consists of lymphocytes or white blood cells made in bone marrow
these travel in the blood and lymph OR stay in lymph organs like modes, tonsils, and spleen
what are the two types of specific lymphocytes?
b and t cells
what do b cells do?
pt 1 in 3rd line
they mature in bone marrow and make antibodies that have protein markers to bind to specific antigens that fit
pt 2 in 3rd line
def of plasma cells
then plasma and memory cells are made
antibody cell mediated antibodies are made by plasma cells
what do vaccines do to the immune system?
they pre-arm the immune system by sending in a weakened/dead version of the germ just enough to be recognized, but because the threat is low, the cell army disbands quickly
however, all important memory cells have been created and the system is then prepared for the real germ
do b cells come before or after plasma cells?
b cells come before plasma cells
each antigen has a specific…
binding site know as an antigen binding site to attach to the invader
only the specific binding site of the antibody will cause it to divide after exposure to the specific antigen
identical copies of lymphocytes are…
clones
where are antibodies found?
in serum and lymph and on surfaces of b cells
antibodies bound to antigens can kill the antigen by…
- activating host complement system
- attract phagocytes to destroy antigen
- aggregate or clump with the antigen in the membrane forming a hole for fluid to rush in to lyse or burst the microbe
host complement system def
series of serum proteins produced by the liver and work with the antibodies, causing infected cells to burst
summary of 3 lines of defense
first line - mechanical barriers + chemical barriers
second line - inflammation response + phagocytosis
third line - specific immune responses + natural killer cells
what is a pathogen?
a disease causing microbe
what did jenner develop? when?
developed the first vaccine for smallpox in 1796
what did pasteur develop? when?
developed first rabies vaccine in 1860
vaccine def def
dead or weakened microbes which induce specific immunity against the antigens
some microbes change antigen markers to evade antibodies like the flu, hiv
herd immunity def
only when enough get immunized or get the disease does the threat lessen
primary immune response def
antigen exposure causes rapid division of plasma cells into antibodies
it takes 7 days for the minimum amount of antibodies to be made
many of the stimulated b cells become memory cells
secondary immune response def
after re-exposure to the same antigen, memory cells make antibodies in 2-6 days
inborn immunity def
resistance to nonhuman diseases before birth
acquired immunity def
resistance developed after birth/conception
passive immunity def
antibodies put in AND NOT in response to antigens (temporary)
natural passive immunity
from mother through placenta and especially through brest milk
artificial passive immunity
ex. gamma globulin IgG, inserted antibodies
active immunity def
antibodies made by the body in response to antigens- more permanent immunity
natural active immunity
antibodies make after infection/disease
artificial active immunity
antibodies made after vaccines of dead/weak antigens are injected
what suppresses immune system reactions?
stress, drugs, HIV
what are allergic reactions caused by?
hypersensitivity -
for example, a poison ivy chemical alters HLA and T cells so they attack their own “foreign” cells with causes inflammation, rashes, and blisters from the release of histamine
allergens can cause constriction of breathing from blocked airways and death
autoimmunity def
antibody or t cells bind to “self” cells due to gene susceptibility or after a virus mistake,
ie rheumatoid arthritis, chrons, etc
what are viral diseases caused by?
the virus reproducing only inside cells (lytic cycle)
ie cold, flu, corona, hiv, hepatitis, measles
how to bacterial diseases reproduce
though binary fission
ie cholera, bubonic plague, lyme, genome, syphilis, strep throat, etc
how are protozoan diseases caused?
by 1 celled eukaryotes classified by type of movement
helper T cells, immunity mediated by…
antibodies
killer T cells, immunity mediated by…
cells
suppressor T cells, immunity mediated by…
antibodies
memory B cells, immunity mediated by…
antibodies
plasma B cells, immunity mediated by…
antibodies
macrophages, immunity mediated by…
antibodies
where do t cells mature?
thymus
where do b cells + macrophages mature?
bone marrow
function of helper t cell
Activate B cells ,T cells, and macrophages to help with most adaptive immune responses
function of killer t cell
Kill foreign cells
function of suppressor t cell
Stimulate B cell to stop antibody production when enough are made/when antigen is defeated
function of memory b cell
To activate other cells needed as well as go to the site of infection to kill off bacteria, and to memorize the bacteria so when it comes again, it will be recognized and defense mechanisms will work more quickly against it
function of plasma b cell
Secrete antibodies
function of macrophages
Surround and destroy any foreign matter
