Mircobiology Ch. 15

innate immunity

comprises the organism’s nonspecific host defenses against infection; exists due to genetic makeup of the organism

adaptive immunity

comprises the organism’s sepcific host defenses; “memory” after exposure to infectious agent

first line of defense

skin, mucous membranes, normal flora

second line of defense

phagocytes, neutrophils, eosinophils, basophils, inflammation, fever

third line of defense

lymphocytes, T cells, B cells, anitbodies

nonspecific immunity

mechanical barriers, chemical barriers, cellular barriers, and microbial antagonism

natural resistance

mircoorganisms are species specific in regard to pathogenicity

age, stress, and diet

changes in normal flora, anatomical changes related to aging, immune status. differences in disease in children, adults, or elderly

mechanical barriers

hair, skin, mucous membranes, coughing and sneezing

skin

nutrient poor, low pH, constantly shedding, dry, salty, unsaturated fatty acids

mucous membrane

constatntly shed, mucous production, chemical barriers, cellular barriers, normal flora

lacrimal gland

tear fluid constatntly bathes the eye and drains into the nose, saliva is similar

stomach acid

pH is 2, kills mircoorganisms

lysozyme

in all body fluids; breaks down peptidoglycan and produces holes in outer membrane

defensins

antimicrobial peptides produced by the body and secreted into the mucous; make foreign cell leaky causing death

bile

mixture of substances produced by the liver and stored in the gallbladder; digestive enzymes that break down many bacteria

transferrin/lactoferrin

proteins that bind up all the free availiable iron to deprive microorganisms; iron essential for growth

interferons

broad nonspecific antiviral activity; activate NK cells and macrophages

interferons

warn neighboring cells to produce molecules to prevent viral replication

toll-like receptors

detect microbial products; trigger innate immune repsonse

complement

eliminate antigens by promoting phagocytosis and damaging membranes of antibody-bearing cells; stimulates larger immune response by attratcing immune cells

classical pathway

antigen/anitbody complexes trigger pathway

C3A

potent inflammatory agent released

C3B

binds to organisms surface and promotes phagocytosis

alternate pathway

pathogen surfaces activate this pathway

mannose binding lectin pathway

MBL binds to mannose on pathogen surfaces triggers this pathway

membrane attack complex

C5b - C6 - C7 - C8 - C9; makes a hole in cells surface

C5A

protent inflammatory agent

C5B

binds to organism’s surface

Neisseria gonorrhea and Neisseria menigitidis

lock of complement common diseases

bone marrow

blood cells are produced here

phagocytosis

cells ingesting debris or foreign cells

cytokines

chemical messengers; reach out to cells near and distant and send important signals

chemokines

lead to immune cell recruitment to the site of infection

C-AIDE

process of phagocytosis (acronym)

chemotaxis

come to thing to be eaten

adherence

bind to thing to be eaten

ingestion

engulf and bring into cell to make phagosome

disgestion

digesitve enzymes from lysosome being put into phagosome

excretion

debris is released for the use by other cells

neutrophils

rapidly move to sites of damage/infection; eat until they die

basophils

allergic/anti-worm; release histamine

eosinophils

parasites/allergies; release granules to kill large infectious agents

monocytes

immature macorphages in the blood

mast cells

promote vasodilation, inflammation, agiogenesis, recruit immune cells

dendritic cells

migrate to all tissues; pick up material in the tissue and take it to immune tissues

natural killer cells

release granules that kill infected/abnormal host cells