Ch.12 Body Defences Flashcards
What are the 5 functions of the immune system
- eliminate potentially harmful substances
- eliminate abnormal and cancerous / mutant cels originally in the body
- eliminates foreign / non-self substances
- eliminates worn out RBC’s, tissue debris and invading pathogens
- allergic responces
what are the malfunction of the immune system
- allergies
- autoimmune diseases
Example of autoimmune diesease
- Rhematoid arthristis
- MS
- Diabetes mellitus
inate defences respond
rapidly
Inate defences function
- non specifically defends agains foreign invaders
- inherited / built in defences
what is used to distiguish invaders as foreign
TLR’s
cells of the inate immune system
- neutrophils
- macrophages
- basophils
- natural killers
types of inate defences
- chemical
- physical
Chemical defences are also called
internal defences
types of internal defences
- interferon
- complement system
- inflammation
- natural killer cells
interferon
- non specifically defend against viral infection
complement system
- complements the actions of antibodies to kill foreign cells by forming membrane attack complexes (MAC)
Natural Killer Cells (NK)
- non specifically lyse and destroy virally / cancer infected host cells
purpose of INF
- acts as a wistle blower to warn neighboring cells
Interferon cells process
- virally infected cells relases INF into the ECF which triggers the production of virally blocking enzymes in healthy cells to:
- breakdown viral mRNA
- inhibit protein synthesis in host / healthy cells
Function of interferon cells
- breakdown viral mRNA
- inhibit protein syntheisi in host/ health cells
3 other functions of Interferon
- enhances phagocytic activity and antibody production
- enhances NK and T lymphocytes, cytotoxic T cells
- slows cell division and suppress tumor growth
the complement system activiates when
- it is exposed to CHO chains on the surface of a microorganism
the invaders directly _______ the invaders
lyse
How is MAC formed? (process)
- complements (c1 –> plasma protein inactive form)
- activates c2, c5, c9
- components c5-c9 asseble to form MAC
components _________ assemble to form MAC
C5-C9
how do MACS destroy pathogens
- punch holes in the victim surface membrane
- membrane becomes leaky and causes entry of water through Osmosis
- causes the cell to burst
what is inflammation
(3points)
- the non specific immune response to foreign material or tissue damage
- is an essential inate responce to microbial invasion
- attracts phagocytes and plasma proteins to an invaded or injured area
phagocytes purpose in inflammation (3 points)
- isolate, destroy, or inactivate the invaders
- remove debris
- prepare fro sequential sequence and repair
sequence of inflammation
defence by resident tissue macrophages –> localized vasodilation –> increased capillary permeability –>localized edema –> walking off inflammed area –>emigiration of leukocytes –> leukocyte proliferation –> markingof destruction of the by Opsin –>leukocyte destruction of cell –>mediation of inflammatory responce by phagocyte secreting chemical –> tissue repair
what is the first step in the inflammation sequence
defence by resident tissue macrophages
defence by resident tissue macrophages
- stationary but become mobile units and migrate to invaded tissue –> phagocytose foreign microbes when entering through the skin
what is the second step in the sequence of inflammation
localized vasodialtion
localized vasodilation
bacterial invasion at the injured site –> attracts most cells –> release histamine –> enhances arteriolar dilation –> attracts more leukocytes and plasma proteins
what is the third step in the inflammation sequence
increase capillary permeability
Increased capillary permeability
- mast cells at the injured site relase histamine –> enlarges capillary pores (increases capillaries) –> allows leakage of proteins from the blood to enter the inflamed area
what is the fourth step in the inflammation sequence
localized edema
localized edema
- accumulation of plasma proteins in intersticial fluid elevates the local intersticial fluid colloid osmotic pressure —> causes edema —> causes symptoms of inflammation
what does an increased interstical fluid colloid osmotic pressure do
- moves fluid out of the capillay and accumulates at the injured area
edema is
swelling
what are the symptoms of inflammation (4)
- redness
- heat
- swelling
- pain
what is the redness caused by
- increased arteriolar vasodilation
- increased blood delivery
heat is caused by
- increased arteriolar vasodilation
- increased blood delivery
swelling is casued by
- increase local capillary permuability
- increased fluid
what is pain caused by
- increased local capillary permeability
- increased fluids; increased prostaglandin
what do prostaglandin do
- causes attraction of more plasma proteins
what is the fifth step in the inflammation sequence
walling off the inflammed area
walling off the inflammed area
- leaked plasma proteins thromboplastin- thrombin and converts fibrogen to fibrin –> this forms a clot around the bacterial invader and damaged tissues
purpose of walling off
- prevents spread
what is the sixth step in the inflammation process
emigration of leukocytes
what are the three step in emigigration of leukocytes
- margination
- dipedsis
- chemotaxis
margination
- inflammation atraacts neutrophils and monocytes –> attatch to the inner endothelial lining
how long does it take for neutrophils to come to the inflmmed area
1 hour
how long does it take monocytes to come to the inflamed area
8 - 12 hrs
adhered leukocytes leave capillaries through
diapedsis
what chemical mediators do inflammed tissues release
chemokins
how do chemokine attack phagocytic cells
chemotaxis
chemotaxis
- chemokines bind with receptors on plasma membrane
- phagocytic cells increases calcium into the cell
role of calcium in inflammation
- switches cellular contractile apparatus to lead the crawling of phagocytic cells towards the inflammed tissue
what is the 7th step in the sequence of inflammation
leukocyte proliferation
leukocyte proliferation
- inflammed tissue releases chemical mediators – causes bone marrow to proliferate – large numberof neutrophils, monocytes, and macropages to eliminate invaders and heal tissues
what is the 8 step in the sequence of inflammation
marking of bacteria for destruction by opsinin
marking of bacteria for destruction by opsinin
opsin c3-b attatch to TLR’s on phagocytes –> increases phagocytosis by linking foreign cells to a phagoctic cell
where is opsin c3-b produced
by the liver
what is the ninth step in the inflammation sequence
leukocyte destruction of the cell
leukocyte destruction of the cell
- macrophages and neutrophils release enzymes (lysozomes) to break down and phagocytose the trapped bacteria –> forms pus
what is pus
- a collection of dead macrophages, cellular debris, lysozomal phagocytes, and bacteria
what is trhe tenth step in the inflammation sequence
mediation of the inflammatory responce by phagocyte secreting chemicals
mediation of inflammatory responce
- microbe stimulatatinf phagocytes release chemicals / chemokines, which stimulates mediate inflammatory responces
mediate inflammatory responces include
- immune activities
- local responces to systemic manifestation
- microbal invasion
what is the purpose of LEM
- prevent bacterial multiplication
- stimulates acute phase proteins
in which step is LEM secreted
10th
acute phase proteins include
- interlukin 1 (IL-1)
– endogenous pyrogens (fever)
what is Il-1 secreted by
activated macrophages
interlukin 1 functions
- proliferation and differentation of the T and B lymphocytes for
- antibody production
- cell mediated immunity
what is the purpose of an increased temperature in the inflammatory responce
- high temperature interferes with bacterial multiplication
when endogenous pyrogens are secreted into the blood it stimulates
prostiglandins
prostiglandins reach the __________ and stimulate the _______
- hypothalamus
- thermostat
what is the eleventh step in the inflamation sequence
tissue repair
tissue repair
- fibroblast rapidly divide and secrete large amount of collagen to fill vacated region
physical defences are also called
external defences
what are the two classes of adaptive immunity
- antibody mediated immunity
- cell mediated immunity
antibody mediated immunity is also called
humeral immunity
antibody mediated immunity involved the productions of _________
antibodies
humeral immunity involves ____ lymphocytes
b
B lymphocyte derivatives are known as
plasma proteins
purpose of B cells
- recognize and respond to bacteria
- “eye” of the adpative immune system
where do B lymphocytes originate
- the red bone marrow
plasma cells produce and secrete
ImG antibodies
when are plamsa cells formed
on intitial contact with antigen
purpose of plasma cells
- antibody combines with antigen and marks for destruction
memory cells can be induced by ________ or ________
- disease
- vaccination
purpose of memeory cells
- provide quicker, more potent, quicker, longer lasting response when faced with the same antigen
macrophages are also called
antigen presenting cells (APC)
what are antigens
- surface protein molecules that marks microbe as a “foreigner”
antigens stimulates b cells to
- proliferate and differnetiate into plasma proteins to produce antibodies
self antigens cause
- autoimmune diseases
what arepurpose of antibodies
- neutralize and aggultinate antigen-antibody complexes and bacterial toxins
antibodies are synthesisized by
- plasma proteins in responce to an antigen / foreign material
what shape are antibodies
y shaped
antibodies are coposed of
- four inter-linked polypeptide chains
the tails of antibodies are
- fucntional properties
- the tails are the same in each subclass
IgM
- serve as b cell surface recpetor for antigen attatchment
- secreted in the early stages of plasma celll responce
IgG
- most abundant
- produced when exposed to the same antigen
- enchances phagocytosis
IgE
- protects against parasitic worms
- immune mediator for common allergic reactions
IgA is found in
- found in secretion of digestive, respitory and genitourinary stytem, milk, and tears
IgD
- prensent on the surface of many B cells
- function is uncertain
what antibodies are responsible for most specific immune responses
- IgM
- IgG
what are the tree steps in antibody neutralization / aggulation
- aggualtion
- precipitation
- neutralization
agglutination
- foreign cells or mismatched tranfused RBC’s bind together as a clump
precipitation
- antigen-antibody complexes invlove soluable antigens (tenus toxins), lattices / chains become large and precipitate out of the solution
what is an example of a soluable antigen
tetnus toxins
neutralization
- prevent toxins from entering neighboring cells
- prevent some antigens from excreting their dentrmental effects
antigen - antibody complexes
- binding cross links numerous antigens into chains / lattices
