chapter 11 study questions Flashcards
invasion and multiplication of a pathogen in the human host is referrd to as
infection
________ can be characterized by any deviation from the healthy state
disease
pathologic state involving the disruption and destruction of tissues by microbes is referred to as _______ disease
infectious
microbes that are part of the normal microbiota are termed
colonists
laboratory cultivation _______-estimates the # and variety of microbes in the normal microbiota
under
true statements regarding the microbiota
our resident microbes produce enzymes that help us digest food
viruses are found in healthy human in large numbers
while the ______ found on one body site may differ from that found in another location, the ________ profile was similar between body locations
microbiota; protein
correct statements about microbiome in humans
comp of gut biota has an influence on obesity
healthy people have dangerous pathogens, in small amounts
examples of sites that harbor normal microbiota
lungs, mucous membranes, vagina, bladder, urethra, mouth
indicates a relationship in which resident microorganisms prevent the overgrowth of intruder microbes when competing for survival in a common enviro
microbial antagonism
which class are not generally discussed in the context of normal microbiota
viruses
body sites in which microbial DNA has been detected, but microbes have not been definitively observed
blood and brain
disease situations in which a person may be susceptible to infection and disease caused by members of the normal biota
poor hygiene practices allows E. coli to enter urinary tract
immune system is compromised by HIV
microbes enter the blood stream due to injury
what of an infant becomes colonized as it comes in contact with family members
skin, gastrointestinal tract, resp tract, genitourinary tract
broad concept that describes an organisms potential to cause infection or disease is called
pathogenicity
pathogen capable of causing disease in healthy person with normal immune defenses is referred to as
true pathogen
describes the degree of pathogenicity of a microbe
virulence
an infection caused by more than one microbes is
polymicrobial infection
the route a pathogen uses to get into the human host cell is called
portal of entry
a pathogen is a microbe whose relationship with its host is ________ and results in infection and ________
parasitic
disease
infection with a member of normal biota, rather than an agent from the outside, is a _________ infection
endogenous
infection originating from a source outside of the body
exogenous infection
t or f
some pathos can only cause disease if they enter a specific portal of entry
true
the route at which a pathogen enters a host
the gastro tract is the portal of entry for pathogens contained in ____ substances
ingested
an infectious dose is the
minimum number of microbial cells required to cause an infection
t or f
if the inoculum is much larger than the infectious dose, the onset of the disease can be extremely rapid
true
the process by which microbes gain a more stable foothold on host tissues is called __________
adhesion
a pathogen can indirectly damage its host by
inducing excessive immune response
a patho can DIRECTLY damage its host by
secretion of exoenzymes
secretion of toxins
secreted by microbes and breakdown and inflict damage on tissues, dissolve host defense barriers and promote spread of microbes to deeper tissues
exoenzymes
ie. mucinase (digests protective coating on mucous membranes)
hyaluronidase (digests hyaluronic acid that substance that cements animal cells together)
coagulase (causes clotting of blood or plasma)
a chemical called lipopolysaccharide (G-) cell walls; differs from exotoxins because it has a variety of systemic effects on tissues and organs ie. fever, diarrhea, hemorrhage
endotoxin
process by which microbes gain a more stable foothold at the portal of entry through interaction of their molecules with host cell receptors
adhesion
step three of infection
hint: phagocytes
surviving host defenses
substances produced by Streptococcus and Staphylococcus that are toxic to WBCs
leukocidins
three major ways in which microbes damage their host
directly through action of enzymes or toxins (endo and exo)
indirectly by inducing an inappropriate host response
epigenetic changes made to host cells by microbes ie. silencing genes
toxin that generally affects cells by damaging cell membrane and causing lysis or by disrupting intracellular function
exotoxins
microbes enter the body and remain confined to a specific tissue ie. boils, warts
localized infection
infection spreads to several sites and tissue fluids - usually via blood stream -
ie. mumps, rubella, AIDS, syphilis
systemic infection
infectious agent spreads from a (usually asymptomatic) local site and is carried to other tissues
focal infection
a second infection caused by a different microbes which COMPLICATES a primary infection
ie. influenza complicated by penumonia
secondary
infection that comes on rapidly, with severe but short lived effects
acute infection
ie influenza
signs of inflammation
edema (accumulation of fluid in an afflicted tissue)
granulomas and abscesses (walled of collections of inflammatory cells and microbes in the tissues)
lymphadenitis (swollen lymph nodes)
increase in the level of white blood cells is
and decrease in level of WBCs is
leukocytosis
leukopenia
small numbers of bacteria or viruses are found in the blood
bacteremia and viremia
asymptomatic or ________
subclinical
a morbid complication that follows a disease
ie. polio can produce paralysis
sequela
the time from initial contact with the infectious agent to the appearance of the first symptoms; the agent is multiplying at the POE but has not yet caused enough damage to elicit sx
incubation period
when the earliest notable symptoms of many infections appear such as feelings of malaise, discomfort, and muscle aches and upset stomach
; short period of 1-2 days
prodromal stage
when infectious agent begins to multiply as high levels, exhibits greatest virulence, and becomes well established in its target tissue
acute phase
phase when recovering, and pt’s strength and health gradually return, owing to the healing nature of the immune response
convalescence phase
fifth phase only some infections have; when infectious agent lingers indefinitely after the patient is well OR the organism is gone but sx continue ie typhoid fever
continuation
three examples of exoenzymes
hyaluronidase
mucinase
coagulase
streptokinase
hemoLYSIN
toxin breaking down blood cells; causes release of Hemoglobin
toxin that acts on the intestines
enterotoxins
which type of toxin have effects on specific cell type
exotoxin
microbial PROTEINS with a strong specificity for a target cell that exert extremely powerful, sometimes deadly effects on cells are called
exotoxins
two properties of exotoxins
toxic in minute amounts
only toxic to specific cell types
a toxin that is part of the outer membrane in a gram neg bacterial cell
endotoxin
what appears when bacteria growing on blood agar produce hemolysins
green tinted zones in agar
the massive drop in blood pressure that can result from the release of LPS in gram neg infections is called _________
septic shock
LPS is located in the ______________ of the cell envelope of gram neg bacteria
outer membrane
what is not a systemic effect of endotoxin release
increased BP; it would actually decrease if anything with shock
endotoxic/septic shock is characterized by a massive drop in BP that can result from the release of LPS in gram neg infections
true
two examples of systemic infections
AIDS
typhoid fever
when a disease can be identified by a certain complex of signs and sx, it can be termed a
syndrome
common sx of inflammation
pain, soreness, fever, and swelling
represent collections of microbes and inflammatory cells that have been walled-off within the tissues
abscesses and granulomas
is the swelling of one or more lymph nodes
lymphadenitis
SIGNS of inflammation
granulomas, abscesses, edema, lymphadenitis
a nonspecific response to tissue injury or infection that protects the host from further damage is called
inflammation
SYMPTOMS of inflammation
pain soreness
decrease in circulating WBCs
leukopenia
abnormally large number of WBCs in the blood
leukocytosis
route through which a pathogen exits from the host organism
portal of exit
a state of inactive infection is called
latency
the incubation period is characterized by
pathogen multiplication
the earliest notable signs of many infections appear as vague feelings of discomfort during the short period known as the _______ stage
prodromal
the primary habitat in the natural world in where a potential pathogen makes its home
reservoir
a _________ is the individual or object from which an infection is actually acquired
transmitter
t or f
in some cases the reservoir and the transmitter for an infectious agent are the same
true
an individual who inconspicuously shelters a pathogen and spreads it to others without any notice is a
carrier
uninfected medical and dental personnel handling materials that are heavily contaminated with patient secretions and blood can accidentally transfer infectious agents to other patients, acting as ________ carriers
passive
a ________ carrier continues to be infectious during the recovery period
convalescent
a carrier who spreads an infectious agent in the period before they develop sx of the disease
incubating carrier
an infection indigenous to animals that is also transmissible to humans is called a
zoonosis
a disease is ________ when an infected host can transmit the infectious agent to another host and establish infection in that host
communicable
if the disease agent is highly communicable, especially through direct contact, the disease is considered to be
contagious
a disease that does not arise from host to host transmission of the infectious agent is called
noncommunicable
any inanimate object that can serve as a vehicle for the spread of disease when contacted by an infected individual is called a
fomite
infectious diseases that are acquired or develop while being treated in a hospital or medical facility are called ____ infections
nosocomial
healthcare-related
__________ transmission occurs when an agent is transferred from an infected person to another infected person without an intermediate object, substance, or space
contact
what term refers to the agent that causes an infection and disease
etiological (etiology)
what discipline involves the study of the frequency and distribution of the disease and other health related factors in defined populations
epidemiology
a disease that must be brought to the attention of local, district, state, or national agencies by medical personnel aware of the condition, in accordance with the law, is a _________ disease
reportable disease
an epidemiological term for “keeping track of trends in nonemergency times” as an aid to predict disease patterns is
surveillance
name three reportable diseases in the US
anthrax
rabies
Lyme disease
the agent that causes an infection and disease is most commonly referred to as the ________, or causative, agent
etiologic
the total number of cases of a disease in a certain area at any given time is referred to as the _________ of the disease
prevalence
term indicating a measure of new cases of a disease over a specific time period, indicating both the rate and risk of infection
incidence
prevalence can be calculated as the (total number of cases in a population) divided by the (total number of people in population) times (_________)
100
list three reportable diseases besides lymes, anthrax, and rabies
shigella, measles, HIV infection, gonorrhea
an epidemic curve show what
the incidence of the disease plotted against time
R0 factor (r naught)
measures susceptible people one infected person will spread the infection to
the case fatality rate is a measure of
the number of people who die of the disease / the number of people infected
the ______ case refers to the first patient found in an epidemiological investigation
index
the number of persons afflicted with a certain illness is called the ______ rate
morbidity
an infectious disease that exhibits a relatively steady frequency over a long period of time in a particular geographic locale
ie. Lyme disease is endemic to certain areas of the US where the tick vector is found
endemic
if occasional cases of disease are reported at irregular intervals in random locales the disease is described as
sporadic
a ________ occurs when the prevalence of a disease is greater than expected for a particular population
epidemic
the spread of an epidemic across continents is a ______
pandemic
the use of fecal transplants to treat patients with C. diff infection has been approved by the US FDA for
patients who do not respond to standard therapy
