Exam 4 Study Guide Flashcards
List blood formed elements and describe their functions.
- Bone marrow: tissue in the long bones of arms and legs; all cells originate from bone marrow
- Thymus: above the breast bone; cells go from the bone marrow to the thymus to develop
- Spleen: filters the blood for dead red blood cells and filters infection of white blood cells
innate immunity
inbuilt immunity to resist infection
o Main players: anatomical defenses, inflammation, fever, phagocytosis, complement proteins
acquired immunity
immunity established to adapt to infection
o Specificity, tolerance, and memory
List innate immune system components protecting Genito-Urinary Tract
• Mucous membranes that line the cavities, continual shedding of it
• Microbial antagonism:
o Normal flora that compete with pathogens for specie and nutrients – promote overall health by providing vitamins to the host
what does acquired immune tolerance mean?
• The ability to produce antibodies against nonself antigens while “tolerating” (not producing antibodies against) self antigens. T cells are an example
compare the layers of skin and mucous membrane and their role in the immune system
• Skin: Perspiration (high salt), Sebaceous glands secrete oil (low pH)
- Lysozyme- destroys cell wall of bacteria
- Epidermis, Tightly packed layer of cells, Shedding of dead cells
• Mucous Membrane: Line body cavities open to the outside
- Epithelium: Thin layer composed of tightly packed
live cells
- Continual shedding of cells carries attached germs
away
what are the elements of the first line of defense?
o Normal flora (bacteria and yeast)
o Epithelium
o Skin
o Macrophages in the lungs
what are the elements of the second line of defense?
o Lipases, nuclease, protease, lysozymes
o Macrophages
o Serum proteins
o Complement proteins
what are the elements of the third line of defense?
o IgG, IgM, IgA, IgE
o Cytokines
o Antibody-mediated Immunity (AMI) and Cell-Mediated Immunity
Name the primary and secondary lymphoid organs, where are all blood components are originated?
- Primary: bone marrow
- Secondary: spleen, lymph nodes, tonsils, lymphatic tissue, MALT, SALT, and BALT
- All blood components come from the bone marrow
Describe how lymph nodes and spleen are involved in immune system
• Lymph nodes: collect free liquid and put back into the body for circulation
o Pea sized organs
o Contain white blood cells
o Trap any incoming bacteria
o Under the armpits and groan
o Lymphoid tissue: drainage and collection field
• Spleen: apart of the blood system
o Filters the blood for red blood cells
o Filters out infection from the blood (with WBC)
Name the elements involved in nonspecific immunity, Give examples for each.
- Prevents pathogens from entering into the body
- First line of defense
- This includes the skin, mucous membranes of the respiratory, digestive, and urogenital tracts
how is fever produced?
• Pyrogens (chemicals) trigger the hypothalamus to increase the body’s core temperature, temperature over 37C (98.6 F)
which molecules may induce fever?
o Various types of pyrogens
o Bacterial toxins
o Cytoplasmic contents of bacteria released by lysis
o Antibody-antigen complexes (inflammation)
o Interleukins-1 (IL-1)
• Muscle contractions, increased metabolic activity, and constriction of blood vessels/reduced blood flow, raises the temperature
define inflammation and list its major characteristics
• The release of inflammatory mediators from injured tissue cells initiates
• a cascade of events which result in the signs of inflammation
o nonspecific response to tissue injury due to infection or physical means
o Cardinal signs, redness, warmth, pain, swelling, and altered function
acute inflammatory response
o Quickly developed, beneficial, promotes healing
o events which result in elimination of invading pathogens
o capillary dilation and increased blood flow
o temperature rise stimulates inflammatory response
o restrict pathogen movement
o Recruit phagocytes to the area
chronic inflammation
slow process
o Slow and causes permanent tissue damage
what are the complements and what are their functions?
- Apart of the second line of defense
- A group of plasma proteins that plays a major role in innate immunity.
- Lyse foreign cells, formation of membrane attack complex, Lysis (MAC)
- Attracts phagocytes to the area (chemotaxis)
- Aid phagocytes in doing their job (opsonization)
- Group of 20 or more proteins that bind and destroy infection and are normally not active
- Bind to the surface of bacteria and accumulate (complement fixation) – poke a hole and kill it
briefly compare classical vs. alternate complement pathways
• Classical: The antibody-dependent pathway of complement activation; it stimulates lysis of pathogens, phagocytosis, and other host defenses.
• Alternate: An antibody-independent pathway of complement activation.
o Initiated by repetitive structures on bacteria, like the membrane LPS
o Inflammation and microbial cell lysis
what is the role of acute-phase response proteins in complement fixation?
- Liver proteins that assist in the prevention of blood loss and ready the host for microbial invasion
- Bind to bacterial surfaces and act as opsonin and activate the classical component pathway
What does de-granulation refer to? Which cells are involved?
- De-granulation: apart of the Mast cells, which are bone marrow-derived cells that differentiate in connective tissue
- Mast cells are not phagocytic but when stimulated they rapidly release the contents of their granules in the extracellular environment
what are some examples of granules that are produced?
histamine, prostaglandins, serotonin, heparin, dopamine, platelet-activating factor, and leukotrienes
name several phagocytic cells
• Macrophages, dendritic cells, neutrophils, and eosinophils
what are the main characteristics of macrophages?
involved in phagocytosis; engulfing and ingesting cells infected with bacteria and viruses
o APC = antigen processes cells – detect infection and remove them, process this info and present to T-cells
what are the main characteristics of dendritic cells?
phagocytic cells, more involved in APC than other cells
o Reside primarily in the skin and lungs
define lysosome
• A spherical membranous eukaryotic organelle that contains hydrolytic enzymes and is responsible for the intracellular digestion of substances.
what is the role of lysosome in phagocytosis?
• Phagocytosis: process by which monocytes, macrophages, neutrophils, and dendritic cells recognize, ingest, and digest extracellular microbes. Binds to microbe. Internalize it. Fuse it with lysosome. Digest the microbe
• Different chemicals within lysosomes will degrade the bacteria depending on the type
o Lipases: kills cell membrane
o Nuclease: kills DNA and RNA
o Protease: kills enzymes
o Lysozymes: kills the cell wall
role of neutrophils
Phagocytic (PMN), Major defense against extra-cellular infections
role of T-helper cells
Main players in acquired immunity (CMI)
role of cytotoxic T cells
directly attack target cells infected with intracellular pathogens such as viruses and cancer cells
role of NK cells
Kill malignant cells and cells infected with pathogens
cell-mediated immunity (CMI)
The type of immunity mediated by T cells
o Main players: T helper, cytotoxic T cells, and NK cells
o Effects: altered self-cells, cells infected with viruses, intracellular bacteria, and tumor and cancer cells
Humoral (antibody-mediated) immunity (AMI)
The type of immunity that results from the presence of soluble antibodies in blood and lymph.
o Main players: B cells (antibodies)
o Effects: neutralize toxins, neutralize viruses, marks invaders for attack by immune system components, activate complement system, aids in phagocytosis, and stimulates inflammation
list lymphocytes
B cells, T cells, and NK cells
what are the differences between plasma cells and memory B cells?
• B cells are what is remembered after an infection; they can be kept for months, years, or lifetimes. When an antigen is detected, the B cells turn into plasma cells which produce antibodies that are released and are temporary cells
What does antigen-presenting mean (APC)? List the cells involved in this process?
- Detect infection and remove it; they will also process the information and present it to T-cells to be able to later recognize the infection
- Book definition: Cells that take in protein antigens, process them, and present peptide fragments bound to MHC molecules to T cells
- Cells involved: T-cells, macrophages, dendritic cells, and B cells
natural immunity and examples
acquired through the normal life experiences of a human and is not induced through medical means
o Active natural: person developing their own immune response to a microbe (infection)
o Passive natural: receiving immunity from another person (maternal antibody)
artificial immunity and examples
produced purposefully through medical procedures (immunizations)
o Active artificial: person developing their own immune response (vaccination)
o Passive artificial: person receiving immunity from another (immune globulin therapy)
IgG
major circulating antibody
IgM
first to appear after infection
IgA
major antibody in secretions
IgE
involved in allergic reactions
define opsonization
coating of microbes by serum proteins, which assist with recognition/ingestion by phagocytic cells
What is the effect of opsonization? Name three opsonin molecules
- Effects: molecules that carry out above are called opsonins, such as antibody and complement proteins; bind to microbial cells, coating them for phagocyte recognition
- Three types: acute phase proteins, C-reactive protein (CRP), and mannan-binding lectin (MBL)
Explain different ways macrophages recognize infectious agents and phagocytized them.
- Macrophages identify an infection, Bind to the infectious agent, engulf it, and destroy
- different surface receptors that allow them to bind to and destroy infectious agents.
- Can identify and bind to foreign antigens because they have receptors for cell surface molecules for structures like Pilli, fimbrae, lipopolysaccharides (LPS)
- Can bind to the antigen that the Fc group of an antibody and destroy it through phagocytosis
Why oxygen consumption increases (respiratory burst) during infections
• reactions occur as soon as phagosome is formed
• toxic oxygen products are produced which can kill invading microbe
o these biproducts include: Peroxide, Superoxide, Hydroxyl radical
What are the characteristics of primary and secondary immune response to infection
- When initially exposes to an infection or an antigen, the immune system takes several days to produce a response to that antigen and produce a small amount of antibodies.
- IgM is the first anti-body produced during an immune response, it is the primary antibody produced upon first exposure to a novel antigen.
- When the immune system is exposed to the antigen again, there is a much quicker response to the antigen because of memory B cells and memory T cells.
- The major anti-body produced during a secondary infection is IgG, which is the major circulating anti-body. In addition, the anti-bodies produced typically have greater affinity for the antigen. The immune system has a much more effective response to the infection
Define and list characteristics of antigen, which molecule is the most antigenic.
- Foreign molecules that include: pili, flagella, cell wall, cell membrane
- The molecule that is most antigenic is proteins
Describe how blood cell count (WBC, RBC, Interferon, etc.) laboratory results may be interpreted?
- RBS does not have an influence on infection rates
- High neutrophils means bacterial infection
- High lymphocytes means viral infection
- High eosinophils means parasite infection
- Interferon: free bacteria, largest phagocytic cells in the blood
define immune-complex
- Immune complexes is the interaction between antigens and anti-bodies, which is called the immune complex formation. referred to the interaction between antigens and anti-bodies.
- complement fixation: complement proteins become active and begin destroy target cells by poking holes in them. Classical pathway
aggulation
when anti-bodies bind to insoluble bacterial cell antigens, causing the bacteria to cross-link and clump up. Visible clumps or aggregates of cells or particles; prevents the bacteria from being effective
immunoprecipitation
used to detect soluble antigens, binding of bivalent or multivalent antibodies to antigens forms lattice that precipitates, lattice formation occurs only when there is an optimal ratio of antigen to antibody
opsonization immune complexes
coating of microbes by serum proteins, which assist with recognition/ingestion by phagocytic cells
o Molecules that carry out above are opsonin, such as antibody and complement proteins
o Bind to microbial cells, coating them for phagocyte recognition
what is hypersensitivity?
When the immune response occurs in an exaggerated form and results in tissue damage to the individual
type 1 hypersensitivity
A form of immediate hypersensitivity arising from the binding of antigen to IgE attached to mast cells, which then release anaphylaxis mediators such as histamine. Examples: hay fever, asthma, and food allergies.
type 2 hypersensitivity
A form of immediate hypersensitivity involving the binding of antibodies to antigens on cell surfaces followed by destruction of the target cells (e.g., through complement attack, phagocytosis, or agglutination).
o IgG or IgM antibodies are inappropriately directed against host cell-surface antigens
o Mismatched blood transfusions is an example
type 3 hypersensitivity
A form of immediate hypersensitivity resulting from the exposure to excessive amounts of antigens to which antibodies bind. These antibody-antigen complexes activate complement and trigger an acute inflammatory response with subsequent tissue damage.
o Too many IgG or IgM are produced and not gotten rid of and can trigger an inflammatory response
o Can affect blood vessels, kidneys, and joints
type 4 hypersensitivity
A delayed hypersensitivity response that results from the binding of antigen to activated T lymphocytes, which then release cytokines to trigger inflammation that damages tissue. Type IV hypersensitivity is seen in contact dermatitis from poison ivy, leprosy, and tertiary syphilis.
list immunodeficiency deseases
• Chronic granulomatous disease, X-linked agammaglobulinemia, DiGeorge syndrome, and severe combined immunodeficiency disease (SCID), HIV, malnutrition, severe stress, HIV, and meningitis
What is meant by primary and acquired immunodeficiency?
• Primary: congenital; result from genetic or developmental effect; develop in infants and young children
• Acquired: develop as a direct consequence of some other recognized cause, develop later in life
o Examples include HIV, severe stress, or malnutrition
toxoid vaccines
Chemically or thermally modified by bacteria toxins. Useful for some bacterial diseases/ Stimulate antibody-mediated immunity/ Require multiple doses
o DTP and Tetanus vaccines
attenuated vaccines
o Mild infections/no disease, strong immune response/ triggers CMI
o Viral vaccines trigger a cell-mediated immune response
o Results in herd immunity
o Problems: with reversion, with immunosuppressed, with pregnant
inactivated vaccines
o Problems: May causes inflammatory response and no herd immunity
o Antigenically weak, and needs high or multiple doses, or the incorporation of an adjuvant, to make the vaccine more effective, (also may produce allergic reactions)
what are cytokines?
Soluble proteins or glycoproteins that act as mediators
o released by one cell population that act as intercellular mediators or signaling molecules
o Immune system horomones, inhibit or grow cells, chemotaxis, apoptosis
MHC proteins
collection of membrane proteins (glycoproteins)
o Receptor molecules are like fingerprints
o On all cells except RBC
o Two classes of them
CSF
proliferation; fight infection, promote healing
TNF
kills cells; necrosis factor (tumor necrosis factor)
interferons
fight against viruses; protect other cells
MCH1
Tc (cytoxic T cells) – kills infected cells because cancer cells have different MCH1 receptor molecules
o Kills cells with viruses as well
MCH2
T helper cells; MCH2 cells react, tell T helper cells, produce B cells, which produce plasma cells to make antibodies against the antigen
What are some practical uses of ELISA test? Differences between direct and indirect ELISA?
- Can be used to detect antigens or antibodies in a sample
- Direct ELISA: detects antigen
- Indirect ELISA: detects antibody produces in response to antigen
rheumatic fever
type 2 – myocarditis, heart valve scarring, and arthritis
hemolytic anemia
type 2 – red blood cells
Graves disease
type 2 – thyroid stimulating hormone (TSH)
multiple sclerosis
types 2 and 4 – antibodies and activated T cells, nerves
myasthenia Gravis
type 2– skeletal muscle, neurotransmitter receptors
Lupus
type 3 – DNA, nucleoprotein, cardiolipin, and blood clotting components
type 1 diabetes
type 3 – T cells and pancreatic beta cells
define graft-host disease
Graft cells attack the recipient tissues like in bone marrow transplants
• disease prevented by treating donor with immunosuppressive drugs to deplete marrow of mature T cells