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Immune System Tania Torres-Gomez P.1 - Coggle Diagram
Immune System Tania Torres-Gomez P.1
Functions
lymphatic
managing fluid levels
carry fluid that is leaked from bloodstream back to the blood
reacts to bacteria or cell products that can cause disease
absorbs fats from intestine
removes cellular waste
produce and activate
lymphocytes
B cells
T cells
phagocytize foreign agents
immune system
provides resistance against disease
fight pathogens
bacteria, viruses
innate
first and second line of defense
surface barriers, phagocytes
adaptive
third line of defense
inflammation
attack foreign substance
passive
ready made antibodies introduced to body
Active
occurs B cells encounter antigens and produce specific antibodies against them
first, second, third line of defense
first line of defense
(innate)
external body membranes (skin and mucosae)
Surface barriers skin and mucous membranes along with secretions
Physical barrier
most microorganisms
Produce protective chemicals that destroy microorganisms
Acid
acidity of skin and some mucous secretions- growth- acid mantle
Enzymes
lysozime of saliva, respiratory mucus, and lacrimal fluids
Mucin
sticky mucus line digestive and respiratory tract traps microorganisms
Keratin resistant
weak acids and bases, bacterial enzymes and toxins
Mucosae
provides similar mechanical barriers
Respiratory system modifications- step pathogens
Mucus
coated hairs nose trap inhaled particles
Cilia
upper respiratory tract sweep dust and bacteria- laden mucus toward mouth
Surface Barriers
breached nicks (cuts triggers internal 2nd line defense that protects deeper tissues
second line of defense
(innate)
phagocytes and other cells (inflammation-mechanism)
Phagocytes
white blood cells ingest and digest foreign invaders
Neutrophils
most abundant phagocytes, die fighting, become phagocytic on exposure- infectious material
Macrophages
develop from monocytes and are chief paghocytic cells cells, most robust phagocytic cell
inflammatory response (macrophages, mast cells, WBCs, and inflammatory chemicals
triggered when body tissues are injured
benefits in preventing spread of agents, alerts adaptive immune system, sets stage for repair
acute inflammation
Redness, Heat, Swelling, and Pain
chemicals released- ECF injures tissues/ immune cells
inflammatory mediators
histamine, kinins, prostaglandins (PGs), cytokines
cause:
vasodilation local arterioles
make capillaries leaky
attract phagocytes- area
proteins (interferon and complement proteins)
fever
third line of defense
(adaptive)
attacks foreign substance (longer react than innate)
Innate(natural) and Adaptive (acquired)
Adaptive
specific defensive system eliminates almost any pathogen/ abnormal cell in body
characteristics:
specific
recognizes and targets specific antigens
systemic
not restricted- initial site
memory
mounts even stronger attack- "known" antigens (2nd and subsequent exposures)
Main branches
Humoral
(antibody- mediated) immunity
antibodies produced lymphocytes circulate freely body fluids
together temporarily- target cell
mark destruction
Cellular
(cell- mediated) immunity
Lymphocytes act against target cell
indirectly releasing chemicals enhance inflammatory response/ activating other lymphocytes/ macrophages
three crucial types of cells
lymphocytes
B lymphocytes (B Cells)
humoral immunity
T lymphocytes (T Cells)
cellular immunity
antigen presenting cells (APCs)
do not respond- specific antigens
essential auxillary roles in immunity
third line of defense
attacks foreign substances
Innate
uses first and second lines of defense to stop attacks pathogens (disease causing microorganisms)
First line of defense
external body membranes
skin and mucosae
modifications to stop pathogens
Mucus
coated hairs nose trap inhaled particles
Cilia
upper respiratory tract sweep dust and bacteria- laden mucus toward mouth
surface barriers
breached nicks (cuts triggers internal 2nd line defense that protects deeper tissues
surface barriers
acid
acidity of skin and some mucous secretions- growth- acid mantle
enzymes
lysozime of saliva, respiratory mucus, and lacrimal fluids
mucin
sticky mucus line digestive and respiratory tract traps microorganisms
Second Line of Defense
phagocytes and other cells (inflammation-mechanism)
Phagocytes
white blood cells ingest and digest foreign invaders
Neutrophils
most abundant phagocytes, die fighting, become phagocytic on exposure- infectious material
Macrophages
develop from monocytes and are chief paghocytic cells cells, most robust phagocytic cell
proteins
inflammatory mediators
histamine, kinins, prostaglandins (PGs), cytokines
vasodilation local arterioles
make capillaries leaky
attract phagocytes- area
Humoral response and cellular response
Humoral
(antibody- mediated) immunity
antibodies produced lymphocytes circulate freely body fluids
together temporarily- target cell
mark destruction
Cellular
(cell- mediated) immunity
Lymphocytes act against target cell
indirectly releasing chemicals enhance inflammatory response/ activating other lymphocytes/ macrophages
antigens and antibodies
Antigens
substances can move adaptive defenses and provoke immune response
targets all adaptive immune responses
most large complex molecules not normally found in body (nonself)
Characteristics:
complete antigen/ hapten (incomplete)
contain antigentic determinants
self-antigen
MHC Proteins and Antigen Presentation
T cells respond processed fragments antigens displayed on surfaces cells MHC cells
antigen presentation vital activation naive T cells and normal functioning effector T cells
Self-Antigens
MHC proteins
all cells covered with variety of proteins located on surface are not antigentic- self, may be antigenic- others transfusions/ grafts
Antigen presenting cells
Dendritic cells
found connective tissues and epidermis
act sentinels boundary tissues
Phagocytize pathogens enter tissues, enter lymphatics to present antigens- T Cells in lymph node
most effective antigen presenter known
key link innate and adaptive immunity
Macrophages
widely distributed in connective tissues, lymphoid organs
present antigen- T cells
present antigens- T Cells which not only activates T Cell also further activates macrophages
B Cells
helper T cells interact directly B cells displaying antigen fragments bound- MHC II receptors
stimulate B cells to divide more rapidly and begin antibody function
Antibodies
five major classes
IgM
first secreted plasma cells during primary response
activates complement
exists in monomer and pentamer forms
monomer serves as antigen receptor on B cell surface
pentamer circulates blood plasma
numerous antigen sites make it potent
IgA
secretory Iga found body secretions such as saliva, sweat, intestinal juice, and milk
secretory IGA helps stop pathogens from attaching- epithelial cell surfaces
monomer exists limited amounts in plasma
IgD
found B cell surface
functions B cell antigens receptors
IgG
most abundant antibody plasma 75%- 85% circulating antibodies
main antibody both secondary and late primary responses
readily activates complement
protects against bacteria, viruses, and toxins circulating in blood and lymph
crosses plascenta and confers passive immunity from mother- fetus
IgE
stem end- mast cells/ basophils, end triggers these cells- release histamine and other chemicals mediate inflammation and allergic reaction
secreted plasma cells in skin, mucosae of gastrointestinal and respiratory tracts and tonsils
traces IgE found in plasma
targets and functions
do not destroy antigens. they inactive and tag them
defense mechanisms
Neutralization
most important defensive mechanism
antibodies block specific sites on viruses/ bacterial exotoxins
prevent antigens- receptors on tissue cells
antigen antibody complexes undergo phagocytosis
Agglutination
antigen-antibody complexes- become cross-linked into large lattice-like clumps
Precipitation
soluble molecules (instead of cells) cross-linked- complexes
complexes precipitate out of solution
precipitated complexes easier for phagocytes- engulf
Complement fixation
main antibody defense against cellular antigens (bacteria, mismatched RBCs)
several antibodies bound close together on same antigen- connect to sites on their stem regions are aligned
actions
antigen- antibody not destroy antigens, prepare them for destruction- innate defense
go after extracellular pathogens, do not invade solid tissue
4 chains consist
2 identical heavy (H) chains hinge region at "middles"
2 identical light (L) chains
Artificial vs. Natural
Humoral Immunity
Active
Naturally
infection
contact with pathogen
formed response
actual bacteria
Artificially
vaccine
formed response
Passive
Naturally
antibodies passed from mother- fetus via placenta
antibodies delivered
Artificially
injection of exogenous antibodies
injection serum
protection immediate ends antibodies naturally degrade in body
Passive vs. Active immunity
active humoral immunity
occurs B cells encounter antigens and produce specific antibodies against them
Two types
Naturally acquired
formed response- actual bacterial/ viral infection
Artificially acquired
formed response- vaccine
passive humoral immunity
B cells not challenged antigens immunological memory not occur
protection ends antibodies degrade
two types
Naturally acquired
antibodies delivered- fetus via placenta/ infant through milk
Artificially acquired
injection serum, such as gamma glonulin
Disorders associated with the immune system
Immunodeficieny
acquired conditions impair function/ production immune cells/ molecules
SCID syndrome
genetic defect marked deficit B and T cells
Hodgkin's disease
acquired immunodeficiency causes cancer B cells, depresses lymph node cells leads- immune deficiency
Acquired immunodeficiency syndrome (AIDS)
cripple immune system interfering activation T cellls- helper
severe weight loss, night sweats, and swollen lymph node
opportunistic infections
pneumocytis pneumonia and kaposi's sarcoma
Human immunodeficiency virus (HIV)
Autoimmune Diseases
autoimmunity
production antibodies and sensitized TC cells destroys body tissues
arthritis
destroys joints
myasthenia gravis
nerve-muscle connections
multiple sclerosis
destroys white matter myelin
Grave's disease
hyperthyroidism
Type I diabetes
pancreatic cells (destroyed)
Systemic lupus
affects organs
Glomerulonephritis
damages kidney
Pus
creamy yellow mixture dead neutrophils, tissue/ cellls and living/ dead pathogens
abscess
collagen fibers laid down, walling off sac of pus, may need surgically drained
Hypersensitivities
immune responses- perceived (otherwise harmless) threat cause tissue damage
immediate hypersensitivity
acute (type I)
hypersensitive (allergies) begin secs. after contact allergen- antigen causes allergic reaction
initial contact allergen
asymptomatic sensitizes person
Histamines
vasodilation and leakiness of vessels leading symtpons runny nose, itchy hives/ watery eyes
asthma
occur if allergen inhaled
antihistamines
needed-control
Allergic reactions
local/ systemic
system
anaphylactic shock
seen injected allergies
bronchioles constrict, breathing difficult
vasoldilation results decrease blood volume, cause circulatory collapse
Treatment
epinephrine
Lymphatic organs
Primary:
Thymus
chest
fight infection
Red bone marrow
bone
contains stem cells
Secondary:
Lymph nodes
throughout
drain lymph fluid
Tonsils
throat and palate
contain white blood cells, stop germs entering body through mouth or nose
Spleen
upper left side of abdomen
fight invading germs in blood
Peyer's Patches
ilieum region of small intestine
prevent growth of pathogenic bacteria in intestines
Appendix
lower right abdomen
protect good bacteria
malt
various submucosal membranes
prevent pathogens from penetrating mucous membrane
site lymphocyte activation and proliferation
Cells involved
Dendritic cell
act sentinel boundary tissues
mast cell
response to bacteria, contain chemicals (histamine)
Helper T Cell
essential in response, activate B cell, macrophages
Memory Helper T Cell
fast response to antigen, protect against infection with same pathogen
B Cell
produce antigens help fight bacteria and viruses
Memory B cells
antibodies that invade pathogens, remember same pathogen
Neutrophil
effector cells take care of the organism to watch over infections
Monocyte
ingest foreign substances
Eosinphil
created inflammatory response or creates allergic reaction
basophil
causes reaction to allergies
plasma cell
differentiated B cells secrete antibodies, provide protection
cytotoxic
attack
T Cells
activated only when antigen present-them
Antigen
T cell antigen receptors (TCRs) antigen MHC complex APC surface
recognize MHC and foreign antigen
TCR- complex triggers multiple intracellular signaling pathways start T cell activation
Co-stimulation
Complete T cell activation requires t cell- connect one or more co-stimulatory signals surface of APC