What functions are the body's defense mechanism against invasion and allows a rapid response to foreign substances in a specific manner?
What factors affect the immune system?
CNS integrity, general physical and emotional status, medications, dietary patterns, stress of illness, trauma or surgery
What are two types of dysfunctions involving the immune system?
many genetically based, others acquired
What is a property of the immune system that provides protection against harmful microbes?
What is the mechanism by which the immune system is programmed to eliminate foreign substances, but maintains ability to accept self antigens?
What is the concept of surveillance?
the immune system is in a perpetual state of vigilance, screening, and rejecting any invader that is recogned as foreign to the host
Where might disorders from the immune system stem?
excesses or deficiences of immunocompetent cells, alterations in the function of these cells,
immunologic attack on self antigens
inappropriate or exaggerated responses to specific antigens
Where are the central and peripheral lymphoid organs, tissues and cells? (11 - head to toe)
-axillary lymph nodes
-bronchus-associated lymphoid tissue
-Peyer's patches (ascending colon)
-Inguinal lymph nodes
-Bone marrow (B cells and T cells)
**They are also scattered throughout your upper abdomen & left clavicular area
What is autoimmunity?
normal protective immune response paradoxically turns against or attacks the body
What are primary immune deficiencies?
Deficiency results from improper development of immune cells or tissues
usually congential or inherited
What are secondary immune deficiencies?
Results from interference with an already developed immune system, usually acquired later in life
What do the different cells tyles of the immune system defend again?
infection and invasion by other organisms
What supports the immune system?
molecules responsible for the interactions, modulations, and regulation of the system
Immune system molecules interact with immunogenic epitopes and do what?
present on foreign materials
After presenting what do these immune system molecule/epitopes interactions do?
initiate a series of actions in a host
What actions do epitopes initiate?
lysis of microbial agents
disposal of foreign toxins
What do lymph nodes do?
remove foreign material from the lymph system before it enters the blood stream
centers of immune cell proliferation
Why is natural immunity considered the first line of defense?
protect the host with "remembering" prior contact with an infectious agent
How does the natural immune system co-coordinate the initial response to pathogens?
production of cytokines and other effector molecules
What do cytokines do? (2)
(1) activate cells for control of the pathogen (by elimination)
(2) promote the development of the acquire immune response
What cells are involved in the acquired immune response? (7)
natural killer cells
What are the two stages of the natural immune response mechanisms?
immediate (within 4 hrs)
delayed (b/t 4 and 96 hrs after exposure)
How do granulocytes fight invasion by foreign bodies?
releasing cell mediators - histamine, bradykinin, prostaglandins
Which granulocytes increase in number during allergic reactions and stress responses?
What are the nongranular leukocytes?
macrophages (histiocytes in tissue spaces)
Which cells play major roles in humoral and cell-mediated immune responses?
lymphocytes (T and B cells)
How do chemical mediators assist in the inflammatory response? (5)
minimizing blood loss
walling off the invading organism
promoting formation of fibrous scar tissue and regeneration of injured tissue
What facilitates the inflammatory response?
physical and chemical barriers that are part of the human organism
What enhances activation of the natural immunity response?
processes inherent in physical and chemical barriers
What are some chemical barriers of the natural immune response?
acidic gastric secretion
enzymes in tears, saliva
substances in sebaceous & sweat secretions
How can dysfunction of the natural immune system occur?
when immune system components are inactivated or when they remain active long after their effects are beneficial
When is a person considered immocompromised or immunodeficient?
If an immune response fails to develop and clear an antigen sufficiently
What results if an immune system is overtly robust or misdirected?
What is the basis of many autoimmune disorders?
immune systems recognition of one's own tissues are "foreign" rather than as self
How is the inflammatory response regulated?
transformation of macrophage activation-inhibiting growth factor
What holds the promise of preventing graft rejection and aiding the body in eliminating cancerous or infected cells?
research on immunoregulation
How does acquired immunity usually develop?
prior exposure to antigen -
(2) contracting a disease
How long after the exposure does the body produce an immune response sufficient to defend against reexposure?
weeks or months
What are the two mechanisms of the acquired immune response?
(1) cell-mediated response - T cell activation
(2) effector mechanisms - B cell maturation, antibodies
Which type of acquire immunity involves the immunologic defenses developed by the person's own body?
What are examples of passive immunity?
immune globulin or immunity resulting from the transfer of antibodies from the mother to an infant in utero or through breast feeding
What are the body's three means of defense when under attack?
phagocytic immune response
humor or antibody immune response
cellular immune response
What are antibodies?
highly specific proteins that are transported in the bloodstream
attempt to disable invaders
Which cells can turn into special cytotoxic (or killer) cells that can attack pathogens?
T cells (cytotoxic T cells)
What is the structural part of the invading or attacking organism that is responsible for stimulating antibody production?
Why would the body produce a number of antibodies in response to a single single bacterium?
The bacterium has a number of antigens on its surface
What happens once an antibody is produced?
it is released into the bloodstream and carried to the attacking organism
What does the antibody do once it "finds" the antigen?
combines with it
binding with it like a puzzle piece
What are the four well-defined stages in the immune response?
What is the initiating event in any immune response?
recognition of antigens as foreign by the immune system
Where are lymph nodes distributed?
internally throughout the body, in the circulating blood, externally near the body's surface
What play an important role in helping the circulating lymphocytes process the antigens?
What do macrophages and neutrophils coat microorganisms with to enhance phagocytosis?
What triggers the proliferation phase?
circulating lymphocytes containing antigenic messages return to nearest lymphocyte
What do the "sensitized" lymphocytes stimulate once in the node?
T & B lymphocytes to enlarge, divide, proliferate
T cell > cytotoxic T cells
B cell > produce and release antibodies
What does the response stage begin with?
the production of antibodies by the B lymphocytes in response to the specific antigen
What stimulates the resident lymphocytes to become cells that attack microbes directly?
When is lymphocytosis seen in the blood tests of patients?
example: infectious mononucleosis
What happens in the effector stage?
either the antibody of the humoral response or the cytotoxic T cell of the cellular response reaches and connects with the antigen on the surface of the foreign invader.
What characterizes the humoral response?
production or antibodies by B lymphocytes in response to a specific antigen
What is the role of the macrophages and the special T lymphocytes in the humoral immune response?
What are the ways in which B cells recognize and response to invading antigens?
1. directly triggering antibody formation
2. with T cell assistance. T cell returns antigenic material to nodes.
Why does a person who is repeatedly exposoed to the same antigen get an exaggerated and rapid immune response?
B lymphocyte clones with a memory for the antigen.
What are the subunits of antibodies?
light and heavy peptide chain held by disulfide bonds
each unit has a binding site for the antigen and complement system molecule.
How do antibodies defend against foreign invaders?
3. promote the inflammatory response
What is agglutination?
cross-linking antigens causing them to bind or clump together
What is opsonization?
antigen-antibody molecule is coated with a sticky substance
How do antibodies promote the inflammatory response?
promoting the release of vasoactive substances
e.g. histamine, slow-reacting substances
What are the (5) different types of immunoglobulins the body can produce?
IgG - 75%
IgA - 15%
IgM - 10%
IgD - .2%
IgE - .004%
What are the major characteristics of IgG?
appears in serum & tissues
assumes a major role in bloodborne and tissue infections
activates the complement system
crosses the placenta
What are the major characteristics of IgA?
appear in body fluids
protects against resp, gi and gu infections
prevents absorption of antigens from food
passes to neonate in breast milk for protection
What are the major characteristics of IgM?
mostly in intravascular serum
first immunoglobulin produced in response to bacterial and viral infections
activates the complement system
What are the major characteristics of IgD?
Appears in small amounts in serum
possibly influences B-lymphocyte differentiation, but role is unclear
What is the characteristic of IgE?
appear in serum
takes part in allergic and some hypersensitivity reactions
combats parasitic infections
When do the most efficient immunologic responses occur?
whent he anitbody and antigen fit like a lock and key
What is cross reactivity?
poor fit of an antibody to antigen
antibody made in response to a diff antigen
Why does streptococcus pyogenes (acute rheumatic fever) sometimes cause heart valve damage?
the antibody produced cross-reacts with the pts heart tissue - heart valve damage.
Which type of cells represent foreign invaders directly rather than by producing antibodies?
How are cellular reaction initiated?
by the binding of an antigen to an antigen receptor located on the surface of a T cell
Once the T cell identifies an antigen?
carry the antigenic message to the lymph nodes
T cell proliferation stimulated
Which T cell type are activated on recognition of antigens and stimulate the rest of the immune system?
Helper T cells
Which cell type determine whether the immune response will be the production of antibodies or a cell-mediated immune response?
Helper T cells (through the production of specific cytokines)
Which T cell type attack the antigen directly by altering the cell member and causing cell lysis?
Cytotoxic T cells
Killer T cells
What category of cytokines can recruit, activate, and regulate other lymphocytes and WBCs?
What is delayed-type hypersensitivity an example of?
immune reaction that protects the body from antigens through the production and release of lymphokines
What is the purpose of being able to decrease of B-cell production?
keep immune system response at a level that is compatible with health
What types of T cells are responsible for recognizing antigens from previous exposure and mounting an immune response?
Which type of lymphocyte are a subpopulation that destroys antigens already coated with antibody?
Which cells have special receptor sites on their surface that allow them to connect with the end of antibodies?
What is antibody-dependent, cell-mediated cytotoxicity?
null lymphocytes have a special receptor on their surface that allow them to connect with antibodies
How do NK cells respond to infection?
killing infected/stressed cells and by secreting macrophage-activating cytokine
How is destruction of an invading or attacking organism or toxin achived?
-binding of the antibody and antigens
-activation of complement
-arrival of killer T cells
-attraction of macrophages
What are the three major physiologic functions of the complement system?
-defending the body against bacterial infection
-bridging natural and acquired immunity
-disposing of immune complexes and the byproducts associated with inflammation
What important events does activation of the complement allow for?
removal of infectious agents
initiation of the inflammatory response
What points of modication improve the inflammation response and infectious agent removal?
-enhancement of chemotaxis of macrophages & granulocytes
-alter blood vessel permeability
-change blood vessel diameter
-cause cells to lyse
-alter blood clotting
What triggers the classic pathway?
1. antibodies bind to microbes (classic)
part of the humoral type of adaptive immunity
What triggers the lectin pathway?
2. plasma protein + terminal mannose residue on glycoproteins of microbes (lectin)
What triggers the alternative pathway?
complement proteins are activated on microbial surfaces
part of the natural immunity
What contributes to the recruitment of inflammatory cells?
other inflammatory mediators
What do complement components and inflammatory mediators contribute to?
recruitment of inflammatory cells
What else (other than complement and other meditators) contribute to the recruitment of inflammatory cells?
chemokines (group of cytokines)
What type of cells pass through the vessel walls to accumulate at the site of infection?
What is thought to be the cause of many autoimmune diseases?
continued or chronic activation of complement (which in turn results in chronic inflammation)
What is an immunomodulator?
affects the host via direct or indirect effects on one or more components of the immunoregulatory network
What are interferons?
biologic response modifier
nonspecific viricidal protein
naturally produced by the body
capable of activating other parts of the immune system
Interferons are produced by what type of immune system cells?
How are interferons thought to modify the immune response?
suppressing antibody production & cellular immunity
facilitate the cytolytic role of macrophages & NK cells
What are interferons used to treat?
immune-related disorders (MS)
chronic inflammatory conditions (chronic hepatitis)
tumors & AIDS (maybe)
What plays a key reulatory role in the growth and differentiation of bone marrow cells?
What stimulating factors all serve as growth factors for specific cell lines?
granulocyte colony-stimulating factor
granulocyte-macrophage colony-stimulating factor
macrophage colony-stimulating factor
What are the two facets of genetic engineering?
1. combine genes from one type of org with genes from another
2. gene therapy
What is the advantage of mixing genes?
allows cells and microorganisms to manufacture proteins, monokins, lymphokines that can enhance immune system function
What is the advantage of gene therapy?
restoring normal gene function if particular gene is abnormal or missing
What are pluripotent cells?
embryonic stem cells
give rise to numerous cell types that are able to form tissue
What areas are assessed with regards to immunity?
disorders and disease states
What should be the focus of the physical exam?
palpation of lymph nodes
examinations of skin, mucous membranes, resp, gi, gu, cv, neurosensory & musculoskeletal
What are alerting respiratory signs and symptoms with regards to immune dysfunction?
changes in rate
cough (dry or productive)
abnormal lung sounds (wheeze, crackle, rhonchi)
What are alerting cardiovascular signs and symptoms with regards to immune dysfunction?
What are alerting gi signs and symptoms with regards to immune dysfunction?
What are alerting gu signs and symptoms with regards to immune dysfunction?
freq & burning on urination
What are alerting musculoskeletal signs and symptoms with regards to immune dysfunction?
joint mobility, edema, pain
What are alerting SKIN signs and symptoms with regards to immune dysfunction?
hematomas or purpura
edema or urticaria
What are alerting neurosensory signs and symptoms with regards to immune dysfunction?
headaches & migraines
What are the differences in the immune system functions of men and women?
higher incidence of autoimmune diseases in women
What is the role of sex hormones in the immune system?
lymphocyte maturation, activation, synthesis of antibodies and cytokines
What happens in autoimmune disorders with regards to sex hormones?
expression of sex hormones is altered = immune disregulation
What is immunosenescence?
aging stimulates changes in immune system
progressive deterioration in the ability to respond to infections
What are some affects of age on the immune system?
-self-renewal capacity of blood cells decreases
-decline in phagocytes & their activity
-NK cells cytotoxicity decreases (decreased humoral immunity)
-decreased vacine efficacy (decreased acquired immunity)
-increase incidence of autoimmune diseases
What is a suspected reason for the increase in autoimmune disorders in the aged?
1. antibodies can't distinguish between self and nonself
What is a suspected reason for the high incidence of cancer in the aged?
surveillance system can't recognize mutant or abnormal cells
What causes gastroenteritis and diarrhea int he eldeR?
decreased gastric secretions & motility allow normal flora to proliferate = infection
What contributes to the increased risk for UTI in the elderly?
decreased renal circulation, filtration absorption and excretion
prostatic enlargement or a neurogenic bladder
What effect does prolonged exposure to tobacco and environmental toxins have on pulmonary function?
impairs it - decreases elasticity, cilia effectiveness, ability to cough
What does impaired skin integrity predispose older people to?
infection from organisms that are part of normal skin flora
What are some secondary changes experienced int he aged?
breakdown of natural mechanical barriers (skin)
decreased sensation, circulation
What may lead to stasis ulcers, pressure ulcers, abrasions and burns?
increased peripheral neuropathy
decrased sensation, circulation
Deficiency of what vitamin has been assocaited with incrased risk of common cancers, autoimmune disease and infectious diseases?
Which micronutrient may have widespread negative effects on the immune response?
zinc, copper, manganese, selenium
Micronutrients and what other nutrient have a recognized effect on the response of cells and tissues to hypoxic and toxic damage?
What does depletion of protein reserves result in?
atrophy of lymphoid tissue
depression of antibody response
reduction in the number of circulation T cells
impaired phagocytic function
What alteration in nutrition can occur during periods of infection or serious illness?
depletion of protein, fatty acid, vitamin, trace elements
What affect does nutrition status have on postop recovery?
more severe infections
delayed wound healing
What must the nurse assess in regards to nutrtion?
quality of foods ingested
What type of infections have a significant inmpact on health and causes a wide range of deases (oral & genital)?
Herpes simplex virus (HSV)
What immunizations/vaccination does a nurse ask about?
pneumococcal disease (Pneumovax)
What should be initiated during the immunization discuss?
the importance of adhering to the recommended schedule
What is assess and documented with regards to resp infections?
known past or present exposures to TB
dates and results of any tuberculin tests & chest xrays
What STDs is it important a nurse assess for?
hepatitis A, B, C, D, E viruses
What can alter the nurse that the pt may have been exposed to HIV or hepatitis?
history of STDS - gonorrhea, syphilis, HPV, chlamydia
Where are all medication and food allergies listed?
allergy alert sticker and place on the front of the pts health record or chart
What do you ask a pt in regards to allergies?
-types of allergens
-history of testing & treatments (inc OTC)
What is the fifth leading cause of death by disease in females of reproductive age?
What are some autoimmune disorders to ask about?
What strongly suggests a genetic predisposition to moer than one autoimmune disease?
occurence of different autoimmune diseases within a family
What contrubutes to the development of cancers?
immunosuppression (however cancer is immunosuppressive & as is its treatment)
How do tumors prevent the immune system from attack it?
releasing antigens into the blood and preventing the antibodies from attack the tumor itself
also they have blocking factors that prevent killer T cells from attacking it
Which cancers are associated witha ltered production and function of WBCs and lymphocytes?
hematologic cancers - leukemia, lymphoma
What does radiation do?
decreases ability to mount an effective immune response
What determines the extent of immunosuppression caused by radiation?
size and extent of the irradiated area
What affects bone marrow function, destryoing cells that contribute to immune system function?
What factors cause the increased incidence of infection in diabetes?
poor control of serum glucose levels
Why are recurrent resp tract infections associated with COPD?
altered inspiratory & expiratory function
ineffective airway clearance
Why is a history of organ transplantation noted? (also removal of spleen, lymph nodes, thymus)
place pt at risk for impaired immune function
What do major burns cause?
impaired skin integrity
compromise body's first line of defense
loss of large amnts of serum, inc proteins and immunoglobins
What do the stressors associated with surgery or injury stimulate?
cortisol release from the adrenal cortex
What drugs in large doses can cause immunosuppression?
What is a history of blood transfusion obtained?
previous exposure to foreign antigens through transfusion may be associated with abnormal immune function
also small risk of HIV
What "positive" lifestyle factors can also negatively affect immune function?
competitive exercise (causes stress)
MADE WORSE - if exercise is done in a stressful environment
What are psychoneuroimmunologic factors?
bidirectional between the brain and immune system
immune response regulated by neuroendocrine influences
What is the relationship between lymphocytes and the neuroendocrine system?
lymphocytes and macrophages have receptors capable of responding to neurotransmitters & endocrine hormones
lymphocytes can produce & secrete adrenocorticotropic hormone & endorphine like compounds
What can brain cells recognize?
(esp in hypothalamus)
-prostaglandins, interferons, interleukins, histamine, serotonin (inflammatory response mediators)
What biobehavioral strategies can positively influence a measurable immune response?
positively influence relaxation, imagery techniques, biofeedback, humor, hypnosis, conditioning
What drug classification causes immunosuppression?
antineoplastic agents (cytotoxic agents)