Micro Chp 15-21

nonspecific

specific

• 1. mechanical factors
• 2. chemical factors
• 3. normal flora

• - skin- keratin
• - mucuous membrane- ciliary escalator
• - glands
• - hair

• - skin secrete sebum- pH 3-5
• - gastric juice- pH 1-3
• - lysozomes and peroxidase
• - transfeerins in blood compete for iron binding
• - nitric oxide- inhibits ATP production

relationship bewteen microbes and host

give them something to survive off of and they give us something in return

we dont benefit but bacteria isnt harmful either

one benefits at the other expense

• 1. WBC
• 2. phagocytosis
• 3. lymphatic system

phagocytic

produce histamine

toxic to parasites, allergic reactions, some phagocytosis

phagocytosis as mature macrophages

spleen, liver, lungs

roam tissues

cells recruited to infection

• 1. chemotaxis
• 2. attachment
• 3. engulfment
• 4. phagosome lysosome fusion
• 5. destruction
• 6. exocytosis

heat, pain, swelling, redness

histamine, kinins, prostaglandins, leukotrienes

programmed cell death

pyrogens

fever inducing cytokines

bacterial endotoxins

• - inactive proteins
• - strengthens adaptive immunity
• - casade of enzymatic reactions

• 1. classical
• 2. alternative
• 3. lectin

• - quickest and most efficient
• - activation requires antibodies
• - membrane attack complex

• - easily initated
• - activation by C3b to cell surface

- activation requires mannon-binding lectins

cause cells to produce antiviral proteins that inhibit viral replication

causes neutrophils and macrophages to phagocytize bacteria

• 1. cell-mediated
• 2. humoral

• - bone marrow- B cells maturation
• - thymus- T cells maturation

• - encounter antigens
• - nodes, spleen, tonsils

stimulates immune system

• 1. protein structure
• 2. can be carbohydrates
• 3. molecular wieght > 10 kilo Daltons

• 1. Fc region (constant)- determines class
• 2. Fab region (variable)- binding site

• - first to respond to infection
• - pentamer but found on B lymphocytes as a monomer
• - only one formed by the fetus

• - dominant in circulation
• - monomer
• - can cross placenta
• - memory

• - found in secretions, not circulating
• - monomer in serum but dimer in secretions

• - maturation of antibody response
• - monomer

• - barely detectable in circulation
• - monomer
• - allergic rxns

specific response of mature B cells to an antigens epitopes

repeated cycles of cell division generates population of copied antibodies

prevents toxin from interactin with cell

coating of bacteria with antibody to enhance phagocytosis

• - form of natural selection
• - occurs among proliferating B cells

• - T cells never prducec antibodies
• - antigens must be present by antigen presenting cell to T cell receptor

• 1. class 1- expressed on every nucleated cell
• - binds to CD8 cells
• - endogenous
• 2. class 2- expressed only on APC like macrophages
• - binds to CD4
• - exogenous

• - Th1- related to cell mediated immunity, sends out cytokines
• - Th2- activate B cells to produce eosinophils, IgM, IgE

perforin

allergic rxns, TB test

turns off immune system when no antigen in present to avoid autoimmune effect

antigen specidicity

the Fc portion of the IgG antibodies

• no MHC class 1 surface molecule
• - important for viral infections

stimulates CD4

activates CD4, B, CD8, and NK cells

differentiation of CD4 cells

process of destroying B and T cells that react to self antigens

negative

both

differentiation of T cells will only occur if the cell recognizes MHC molecule

antibodies resulting from infection

Ab through placenta

injection of antigens (vaccines)

injection of Ab

live, weakened form of the pathogen

contains killed organisms or inactivated virus

• - usually a single dose
• - has added potential for being spread to un-immunized individuals

- could cause disease in immunocompromised individuals

• - can not cause disease
• - immunogenic- process of gaining immunity

• - magnitude of response is limited
• - no amplification of the dose in vivo (booster shots)

cholera, plague, flu, salk polio

DTP and hep B

immediate IgE mediated

• - inherited
• - charaterized by immediate reaction of the sensitized individual

occurs when antigen induces plasma cells to secrete IgE antibodies

mast and basophils

cytotoxic

IgG or IgM or ADCC that all cause cell death

tranfusion rxns and hemolytic disease of the newborn

immune complex mediated

IgG and antigens form complexes (usually adhere to the Fc receptors are destroyed and removed)

blood clotting mechanism and inflammation

skin, kidneys, joints

delayed cell mediated

cytotoxic T cells that release cytokines that initiate inflammation that attracts marcophages (nothing to due with Ab binding to Ag)

acute life threatening illness causes by infectious agent or its products circulating in blood

• 1. adherence
• 2. colonization- multiplying on a body surface
• 3. delivery of effector molecules that induce changes in the recipient cell

disease transmitted from one host to another

• - must have a suitable environment (reservoir)
• - must leave the reservoir to be transmitted

number of cases of illness divided by population at risk

population that dies from disease

number of new cases per specific time period

total number of existing cases

the extent and distribution of disease

humans, animals, environmental (nearly impossible to elimate)

pathogen passed to next reservoir via contact with food, water or living agent

• - causative agent
• - reservoir
• - route of transmission

survey of range of people to determine prevalence of number of characteristics

comparing to healthy individuals that already had the disease

looking ahead to see if risk factor from retrospective study predict tendency to develop disease

hospital acquired infections

• - length of time of exposure
• - manner of exposure
• - virulence and number of organisms
• - state of host defenses

antimicrobial substance is synthesized and secreted by some true microorganism

antibiotic that is chemically altered after purification to impart new characteristics

antimicrobial substance synthesized in a lab

less

• - inhibit bacterial growth
• - relies on host immunity to eliminate pathogen

• - kills bateria
• - useful when host defenses can not be relied upon to control pathogen

inhibition of cell wall synthesis

• 1. cell wall synthesis- high therapeutic index
• 2. protein synthesis- targets ribosomes
• 3. nucleic acid synthesis- targets enzymes necessary for DNA replication
• 4. metabolic pathways- folic acid

polymyxin B

2 drugs working together