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70 Cards in this Set
- Front
- Back
environment and organsims that inhabit it |
ecosystems |
|
include skin and mucus membranes |
ecosystems |
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Dissimilar organisms living together |
Symbiosis |
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both partners benefit |
mutualism |
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one benefits while other is unaffected |
commensalism |
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parasite derives benefit at expense of host |
parasitism |
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population of microorgansims in/on healthy people |
normal microbiota |
|
microbes that inhabit body for extended periodsof time |
Resident microbiota |
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microbes that are temporary |
Transient micro biota |
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Changes; is dynamic |
normal microbiota/flora |
|
normal flora in fetus |
no normal flora in utero human fetus is sterile |
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how do normal microbiota protect against pathogens |
covering binding sites consuming nutrients producing toxic compounds |
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normal microbiota stimulate ________ immune response |
adaptive |
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prevent immune responses for overreacting to harmless subsances |
Treg cells |
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sufficient exposure can lead to allergies and autoimmune diseases |
hygiene hypothesis |
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5 beneficial roles of normal flora |
1. protect against pathogens 2. stimulates adaptive immune response 3. promoting oral tolerance 4. aiding digestion 5. produce substances important for health |
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how do normal microbiota aid digestion |
1. few enzymes that degrade complex carbohydrates 2. rely on microorgansims to break down most types of dietary fiber |
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bacteria in intestinal tract produce _____ and ______ that can be used by host |
vitamin K and certain B vitamines |
|
establishment of microbe and multiplying on a body surface |
colonization |
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no symptoms or mild enough to go unnoticed |
subclinical infection |
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infection that results in disease |
infectious disease |
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noticeable impatient |
disease |
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does not always lead to illness |
infection |
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subjective effects experienced by the person (pain, nausea) |
symptoms |
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observable effects (rash, pus formation, swelling) |
signs |
|
initial infections |
primary infection |
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additional infection that occurs as result of primary infection |
secondary infection |
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able to cause disease in otherwise healthy person |
primary pathogen/pathogen |
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causes disease when introduced into unusual location or an immunocompromised person |
opportunistic pathogen/opportunism |
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refers to degree of pathogenicity |
virulence |
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traits that allow microbe to cause disease |
virulence factors |
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spreads from one host to another |
communicable/contagious disease |
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number of microbes necessary to establish infection |
infectious dose |
|
number of microbial cells given resulting in disease in 50% of test population |
ID50 |
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interval between introduction of pathogens and disease onset |
incubation period |
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show no signs or symptoms but can infect others |
carriers |
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rapid onset, short duration |
acute infections |
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develops more slowly, lasts longer |
chronic infections |
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never eliminated completely |
latent infection |
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microbe limited to small area |
localized infection |
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infectious agent disseminates throughout body |
systemic/generalized infection |
|
"-emia" |
in the blood |
|
necessary to cause infection |
adherence |
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bacteria use _______ to do attach to host cells |
adhesins |
|
tips of pili and components of capsule or cell wall |
adhesins |
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attach to receptors on host (binding highly specific) |
adherence |
|
prerequisite for production of infectious disease |
colonization |
|
breach anatomical barriers: skin and mucus membranes |
invasion |
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activate in extremely small quantities |
exotoxins |
|
produce by gram-positive and gram-negative |
exotoxins |
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actively secreted or leak out following lysis |
exotoxins |
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most inactivated by heat |
exotoxins |
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generally, carried by bloodstream from point of infection to distant parts of the body |
exotoxins |
|
some can be converted to toxoid |
exotoxins |
|
toxoid |
vaccine |
|
3 types of exotoxins |
A-B toxins membrane-damaging toxins superantigens |
|
enzyme for toxic part (where toxicity comes from) |
A-B toxins |
|
binds to host cell receptors |
A-B toxins |
|
cause cell lysis |
membrane-damaging toxins |
|
stimulate too many Th cells |
superantigens |
|
leads to massive release of cytokines |
superantigens |
|
"cytokine storm" |
superantigens |
|
fever, nausea, vomiting, diarrhea |
"cytokine storm" |
|
can result in organ failure |
superantigens |
|
all are lipopolysaccharides: gram-negativebacteria |
endotoxins |
|
lipopolysaccharides |
gram-negative bacteria |
|
released when bacteria cell is damaged or divides |
endotoxins |
|
resistant to heat |
endotoxins |
|
systemic response can lead to |
fever dramatic drop in BP disseminated intravascular coagulation (DIC) |
|
systemic response |
endotoxins |