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Denise Juarez P.2 Lymphatic/Immune System - Coggle Diagram
Denise Juarez P.2 Lymphatic/Immune System
Purpose & ex. of 1st, 2nd, and 3rd line of defense
2nd:
antimicrobial proteins, phagocytes, and other
cells (inhibit spread of invaders; inflammation most important mechanism)
NK cells (ingest and digest (eat) foreign invaders) ( kills by inducing apoptosis) (enhance inflammatory response)
Inflammatory response (macrophages, mast cells, WBCs, and inflammatory chemicals) (Alerts adaptive immune system) (Prevents spread of damaging agents)
Phagocytes (wbc that ingest and digest (eat) foreign invaders)
Antimicrobial proteins (interferons and complement proteins)
pattern recognition receptors that recognize and bind
tightly to structures on microbes, disarming them before they do harm
fever
cells and chemicals
1st:
external body membranes (skin and mucosae) (surface barriers)
Enzymes: lysozyme of saliva, respiratory mucus, and lacrimal fluid kills many microorganisms; enzymes in stomach kill many microorganisms
Mucin: sticky mucus that lines digestive and respiratory tract traps microorganisms
Acid: acidity of skin and some mucous secretions inhibits growth; called acid mantle
breached by nicks or cuts trigger the internal second line of defense that protects deeper tissues
produces protective chemicals that inhibit or destroy
microorganisms
3rd:
attacks particular foreign substances (takes longer to
react than innate)
Cells involved in immune system & their functions
t cells
Some T cells directly kill cells; others release chemicals that regulate immune response
Cytotoxic
Directly attack and kill other cells
circulate in blood and lymph and lymphoid organs in search of
body cells displaying antigen they recognize
T cells are more complex
Helper T cells
Activate both humoral and cellular arms
without it there is no immune response
Two populations of T cells
CD4
CD8
Cause dendritic cells to express co-stimulatory molecules required for CD8 cell
activation
CD8 cells require TH cell to become activated into destructive cytotoxic T cells
B cells
Helper T cells interact directly with B cells displaying antigen fragments bound to MHC II receptors
Stimulate B cells to divide more rapidly and begin antibody formation
Regulatory T cells
Important in preventing autoimmune reactions
Lymphocytes
cells of the adaptive immune system; mature into one of two main types
Macrophages:
Widely distributed in connective tissues and lymphoid organs
Activated macrophage becomes phagocytic killer
trigger powerful inflammatory responses and recruit additional defenses
Dendritic cells:
Found in connective tissues and epidermis
Phagocytize pathogens that enter tissues, then enter lymphatics to present antigens to T cells in lymph node
Passive vs. Active immunity
Passive -short-term immunity, obtained by receiving antibodies
Active - long-lasting immunity, obtained through antigen exposures
Artificial vs. Naturally acquired immunity
Naturally
Natural immunity is acquired from exposure to the disease organism through infection with the actual disease
Artifical
acquired through the introduction of a killed or weakened form of the disease organism through vaccination
Major Functions of Lymphatic & Immune systems
Immune
recognize and neutralize harmful substances from the environment
fight disease-causing changes in the body
to fight disease-causing germs (pathogens) like bacteria, viruses, parasites or fungi, and to remove them from the body
defends body against infection, whilst protecting the body's own cells
Lymphatic
reacting to bacteria
dealing with cancer cells
managing the fluid levels in the body
dealing with cell products that otherwise would result in disease or disorders
absorbing some of the fats in our diet from the intestine
protecting body from illness-causing invaders
bsorbing digestive tract fats and removing cellular waste
Innate & Adaptive immune defenses
Innate (natural) (nonspecific)
first and second lines of defense
surface barriers
skin & mucous membranes
have specific pathways for certain substances
internal defenses
phagocytes
inflammation
natural killer cells
antimicrobial proteins
fever
responses release proteins that alert cells of adaptive system to foreign molecules
uses the first and/or second lines of defense to stop attacks by
pathogens (disease-causing microorganisms)
Adaptive (acquired) (specific)
third line of defense
eliminates almost any pathogen or abnormal cell in body
cellular immunity ( t cells)
specific: recognizes and targets specific antigens
humoral immunity (b cells)
systemic: not restricted to initial site
memory: mounts an even stronger attack to “known” antigens (second and subsequent exposures)
Location of Lymphatic Organs & Functions
Tonsils
they can stop germs entering the body through the mouth or the nose.
contain a lot of white blood cells, which are responsible for killing germs
Lymph nodes
Most are embedded deep in connective tissue in clusters along lymphatic vessels
Some are nearer to body surface in inguinal, axillary, and cervical regions of body where collecting vessels converge into trunks
Cleansing the lymph: act as lymph “filters"
Immune system activation: offer a place for lymphocytes to become activated and mount an attack against antigens
principal secondary lymphoid organs of body
Thymus
responsible for the production and maturation of immune cells
Primary lymphoid organs:
areas where T and B cells mature red bone marrow and thymus
Spleen
Cleanses blood of aged blood cells and platelets; macrophages remove debris
Site of lymphocyte proliferation and immune surveillance and response
Blood-rich organ about size of fist, located in left side of abdominal cavity, just below stomach
Secondary lymphoid organs:
areas where mature lymphocytes first encounter their antigen and become activated
Red Bone marrow:
contains blood stem cells that can become red blood cells, white blood cells, or platelets
produces blood cells
Peyer's Patches:
Appendix:
play a role in mammalian mucosal immune function
MALT:
Protects from pathogens trying to enter body
Appendix
Peyer's Patches
Tonsils
Antigens & antibodies
Antigens
Targets of all adaptive immune responses
Self-antigens: all cells are covered with variety of proteins located on surface that are not antigenic to self, but may be antigenic to others in transfusions or grafts
substances that can mobilize adaptive defenses and provoke an immune response
most are large, complex molecules not normally found in body (non-self)
Antibodies
4 chains (structure)
Two identical heavy (H) chains with hinge region at “middles”
Two identical light (L) chains
Five major classes: IgM, IgA, IgD, IgG, and IgE
binding specifically with antigen detected by B cells
Immunoglobulins (Igs) are proteins secreted by plasma
cells
Antibodies do not destroy antigens; they inactivate and tag them
Antibodies go after extracellular pathogens; they do not invade solid tissue unless lesion is present
Disorders associated with the immune system
Hodgkin’s disease:
is an acquired immunodeficiency that causes cancer of B cells, which depresses lymph node cells and thus leads to immunodeficiency
Acquired immune deficiency syndrome (AIDS)
: No cure for AIDS found; four major classes of antivirals in combination help but can fail as virus becomes resistant
Severe combined immunodeficiency (SCID) syndrome:
genetic defect with marked deficit in B and T cells
Human immunodeficiency virus (HIV)
cripples immune system by interfering with activity of helper T cells (enter via Blood transfusions; blood-contaminated needles; sexual intercourse and oral sex; mother to fetus)
Immunodeficiency:
congenital or acquired conditions that impair function or production of immune cells or molecules
Autoimmune disease:
results when immune system loses ability to distinguish self from foreign
Autoimmunity:
production of autoantibodies and sensitized TC cells that destroys body tissues
Myasthenia gravis:
impairs nerve-muscle connections
Multiple sclerosis:
destroys white matter myelin
Graves’ disease:
causes hyperthyroidism
Type 1 diabetes mellitus
: destroys pancreatic cells
Rheumatoid arthritis:
destroys joints
Systemic lupus erythematosus (SLE)
: affects multiple organs
Glomerulonephritis
: damages kidney
Humoral response & cellular response
Humoral
b cells
antibody-mediated
Antibodies, produced by lymphocytes, circulate freely in body fluids
B cell encounters target antigen, it provokes humoral immune response
Active:
B cells encounter antigens and produce
specific antibodies against them
Artificially acquired: formed in response to
vaccine of dead or attenuated pathogens
Naturally acquired: formed in response to
actual bacterial or viral infection
Passive:
when ready-made antibodies are introduced into
body
Naturally acquired: antibodies delivered to fetus via placenta or to infant through milk
Artificially acquired: injection of serum, such as gamma globulin
Cellular
t cells
cell-mediated
Lymphocytes act against target cell