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Jessie Castro P.2 Immune System - Coggle Diagram
Jessie Castro P.2 Immune System
Disorders
enterobiasis: white, parasitic worms that live in large intestine of humans
malaria: acute feverish illness that is spread to people through the bites of infected female anopheles mosquitos
toxoplasmosis: foodborne illness
cholera: a diarrheal illness, extremely virulent disease
hepatitis B: vaccine-preventable liver infection caused by the hepatitis B virus; spread when blood, semen, body fluids passed on
polio: disabling & life threatening virus infecting a person's spinal cord, causing paralysis
tuberculosis: disease caused by germs that are spread from person to person through air
hand, foot, mouth disease: a mild, contagious viral infection that effects the mouth, foot, and more
measles: acute viral respiratory illness; highly contagious and can lead to many complications
haemophiles influenza type B: type of bacteria that causes many interactions
chicken pox: highly contagious disease caused by the varicellazoster virus
meningitis: an inflammation in the meninges covering brain & spinal cord
tetanus: infection caused by bacteria clostridium tetanal that produces painful muscle contraction or "lock jaw"
smallpox: a serious infectious disease caused by the variola virus
pertussis: an easily spread respiratory disease caused by the bacteria Bordetella pertussis
rubella: a contagious disease caused by the RUV virus
Purpose of 1st, 2nd, 3rd Lines of Defense
2nd Line
examples: phagocytes, natural killer cells, inflammatory response, antimicrobial proteins, fever
purpose: necessary if microorganisms invade deeper tissues
pattern recognition receptors that recognize and bind tightly to structures on microbes, disarming them before they do harm
3rd Line
examples: memory T cells, Cytotoxic T cells, T helper cells
purpose: eliminates specific pathogens that have been encountered by the immune system previously
1st Line
examples: skin & mucous membranes
purpose: physical barrier to most microorganisms; defends body from infection
Innate & Adaptive Immune Defenses
Inate
1st Line: Surface Barriers
skin: mechanical barrier that prevents entry of pathogens & harmful substances into body
mucous membranes: mechanical barrier that prevents entry of pathogens
skin & mucous membranes produce protective chemicals that inhibit or destroy microorganisms
Adaptive
3rd Line: Adaptive Defense
specific defensive system that eliminates almost any pathogen or abnormal cell in body
specific: recognizes and targets specific antigens
systemic: not restricted to initial site
memory: mounts an even stronger attack to known antigens
humoral immunity: antibodies circulate freely in body fluids
bind temporarily to target cell; mark for destruction
cellular immunity: lymphocytes act against target cell
directly by killing infected cells
indirectly by releasing chemicals that enhance inflammatory response; or activating other lymphocytes or macrophages
2nd Line: Cells and Chemicals
necessary if microorganisms invade deeper tissues
phagocytes: WBC that ingest and digest foreign invaders
neutrophils: most abundant phagocytes, but die fighting; become phagocytic on exposure to infectious
material
macrophages: develop from monocytes and are chief phagocytic cells; most robust phagocytic cell
natural killer cells: attack cells that lack “self” cell-surface receptors; kills by apoptosis
secrete potent chemicals that enhance inflammatory response
inflammation triggered whenever body tissues are injured
benefits of inflammation: prevents spread of damaging agents, disposes of cell
debris and pathogens, alerts adaptive immune system, sets the stage for repair
Major functions of the Lymphatic & Immune systems
Lymphatic
returns fluids leaked from blood vessels back to blood
lymphatic vessels offer a one-way system, ensuring lymph flows only toward heart
collect and filter fluid from your body's cells and tissues
lymph capillaries drain into increasingly larger vessels called collecting lymphatic vessels
lymphatic trunks drain large areas of body
lymph is delivered from trunks into 1 of 2 large lymphatic ducts
right lymphatic duct drains right upper arm and right side of head and thorax
thoracic duct drains rest of body
Immune
innate (nonspecific) defense system
first line of defense: external body membranes
second line of defense: inhibit spread of invaders; inflammation most important mechanism
adaptive (specific) defense system
third line of defense: attacks particular foreign substances
a functional system rather than organ system
provides resistance to disease
Humoral & Cellular Response
Humoral
passive humoral immunity: occurs when ready-made
antibodies are introduced into body
active humoral immunity: occurs when B cells encounter
antigens and produce specific antibodies against them
Cellular
T cells provide defense against intracellular antigens
CD4 cells become helper T cells that can activate B cells, other T cells, and macrophages
regulatory T cells moderate immune response
CD8 cells become cytotoxic T cells that are capable of destroying cells harboring foreign antigens
helper, cytotoxic, and regulatory T cells are activated T cells
naive T cells are simply termed CD4 or CD8 cells
Locations/ Functions of Lymphatic Organs
primary lymphoid organs: areas where T and B cells mature—red bone marrow and thymus
T and B cells originate in bone marrow, but only B cells matures there; T cells mature in thymus
secondary lymphoid organs: areas where mature lymphocytes first encounter their antigen and become activated
lymph nodes: principal secondary lymphoid organs of body
embedded deep in CT in clusters along lymphatic vessels or near body surface in inguinal, axillary, and cervical regions
cleanse the lymph: act as lymph “filters”
offer a place for lymphocytes to become activated and mount an attack against antigens
spleen: blood-rich organ located in left side of abdominal cavity
site of lymphocyte proliferation and immune surveillance/ response
cleanses blood of aged blood cells and platelets; macrophages remove debris
Mucosa-associated lymphoid tissue (MALT): protects from pathogens trying to enter body
found in: Peyer's patches, tonsils, appendix
tonsils: gather and remove pathogens in food or air
Palatine tonsils: at posterior end of oral cavity
Lingual tonsil: lumpy collection of follicles at base of tongue
Pharyngeal tonsil: also called adenoids; located in posterior wall of nasopharynx
Tubal tonsils: surround openings of auditory tubes into pharynx
Peyer’s patches: clusters of lymphoid follicles in wall of distal portion of small intestine
destroy bacteria, preventing them from breaching intestinal wall
generate “memory” lymphocytes
appendix: offshoot of first part of large intestine
destroy bacteria, preventing them from breaching intestinal wall
generate “memory” lymphocytes
thymus: bilobed lymphoid organ found in inferior neck
lymphoid organ where T cells mature
most active and largest in size during childhood
stops growing during adolescence, then gradually atrophies
produces immunocompetent cells slowly
Cells Involved In The Immune System
T cells: manage immune response & attack/ destroy infected cells
B cells: produce plasma cells, which secrete antibodies; antibodies mark antigens for destruction by phagocytosis
macrophages: phagocytize foreign substances and help activate T cells
dendritic cells capture antigens and deliver them to lymph nodes; also help activate T cells
reticular cell: produce reticular fibers called stroma in lymphoid organs
phagocytes: white blood cells that ingest and digest foreign invaders
neutrophils: most abundant phagocytes, but die fighting; become phagocytic on exposure to infectious material
natural killer cells: police blood and lymph
Antigens vs. Antibodies
Antigens
substances that can mobilize adaptive defenses and provoke an immuneresponse
targets of all adaptive immune responses
not normally found in body (nonself)
can be complete/ incomplete
contain antigenic determinants
can be a self-antigen: antigenic to others in transfusions or grafts
Antibodies
proteins secreted by plasma cells
capable of binding specifically with antigen detected by B cells
5 major classes: IgM, IgA, IgD, IgG, and IgE
antibodies do not destroy antigens; they inactivate and tag them
form antigen-antibody (immune) complexes
neutralization: antibodies block specific sites on viruses; prevent antigens from binding to receptors on tissue cells
agglutination: allows for antigen-antibody complexes to become cross-linked into large lattice-like clumps
precipitation: precipated complexes are easier for phagocytes to engulf
complement fixation and activation: main antibody defense against cellular antigens
antibodies can act intracellularly if attached to virus before it enters cell
Active vs. Passive Immunity
Active
occurs when B cells encounter antigens and produce specific antibodies against them
2 types
Passive
occurs when ready-made antibodies are introduced into body B cells are not challenged by antigens
immunological memory does not occur
protection ends when antibodies degrade
Artificial vs. Naturally Acquired Immunity
Active Immunity
naturally acquired: formed in response to actual bacterial or viral infection
artificially acquired: formed in response to vaccine of dead or attenuated pathogens
Passive Immunity
naturally acquired: antibodies delivered to fetus via placenta or to infant through milk
artificially acquired: injection of serum, such as gamma globulin