Exam 3 Flashcards
(166 cards)
1
Q
health
A
a state of relative equilibrium in which the body’s many organ systems function adequately
2
Q
disease
A
a state of functional disequilibrium that may be resolved by recovery or death
3
Q
microbes can be divided into the categories…
A
normal flora
opportunists
pathogens
4
Q
pathogens
A
- will cause disease
- capable of creating their opportunities, do not have to wait for the right one
5
Q
opportunists
A
- can cause disease when the proper opportunity arises
- ex. when the immune system breaks down, the result of a medical treatment
6
Q
normal flora
A
- co-exit with the human body in a stable relationship
- their numbers rarely change
- found on the body’s surfaces
- can be reduced in number by washing but cannot be eliminated
7
Q
where are normal flora found
A
- skin
- conjunctiva
- interior surfaces of the nose
- mouth
- intestinal tract
- urethra
- vagina
8
Q
normal skin flora
A
staphylococcus
Corynebacterium
Propionibacterium
9
Q
Propionibacterium causes
A
acne
10
Q
why doe the conjunctive carry only a few species of normal flora
A
lysozyme in tears
11
Q
example of normal flora in conjunctiva
A
staphylococcus
12
Q
mucociliary system
A
in the nasal cavity
mucus cells and ciliated cells
produce mucos to entrap excess microbes and then ciliated cells brush the mucus with excess microbes away
13
Q
normal flora in nasal cavity
A
staph epidermidis
staph aureus
lactobacillus
14
Q
normal flora in mouth
A
staph epidermidis
staph aureus
strep mutans
15
Q
strep mutans causes
A
tooth decay
16
Q
normal flora in esophagus, stomach, and upper small intestines
A
none - considered sterile tissue
17
Q
normal flora in large intestine
A
Enterobacteriaceae, e. coli, proteus, klebsiella
enterococci, staph aureus, lactobacillus
18
Q
enterobacteriacease is
A
facultative anaerobe, gram neg rod
19
Q
e coli is
A
facultative anaerobe, gram neg rod
20
Q
proteus is
A
facultative anaerobe, gram neg rod
21
Q
klebsiella is
A
facultative anaerobe, gram neg rod
22
Q
enterococci is
A
facultative anaerobe, gram pos
23
Q
staph aureus is
A
facultative anaerobe, gram pos
24
Q
lactobacillus is
A
facultative anaerobe, gram pos
25
normal flora in urethra
upper is sterile
| end contains enterococci and staph epidermidis
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changes in vagina
- newborn has mother's estrogen level making acidic environment with lactobacillus
- after 6 weeks, becomes alkaline reducing lactobacillus and increase growth of staph, strep, enterobacteriaciae, and small amount of candida albicans
- from puberty to menopause, flow will change throughout cycle - during flow, alkaline, as estrogen increases, acidic
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commensalism
one partner is neither benefited nor harmed while the other benefits
ex. normal flora
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staphylococcus
grapelike clusters of coci
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coccobacillus
elongated cocci
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streptococcus
chains of cocci
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streptobacillus
chains of rods
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microbial antagonism
- bacteria have different shapes, helping them use every space available and find a place to live and nutrients to ingest
- they are all looking for a place to live, food to eat, and ability to reproduce
- they search for and lay claim on surface area on body surfaces
- they compete with each other for the same surface and food source, keeping each other's numbers in check as they cover the entire surface
- the prevent pathogens from having space to lay claim of
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mutualism
both partners benefit
| ex. cows cultivate microbes in stomach to allow them to digest cellulose
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microbes that coexist in our gut are thought to be vital to
immune, heart, and lung function
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parasitism
the host is harmed by the symbiotic partner while the partner benefit
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pathogen reserved for
microbial parasites
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parasites reserved for
eukaryotic pathogens like protozoan or worms
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types of symbiotic relationships
commensalism
mutualism
parasitism
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pathogenesis
- microbes ability to cause disease
- how the microbe can function, nothing to do with how well our body defends itself
- can be based on structures and genetic make up of the microbe
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infection
- involves the growth of microbes in the body not considering normal flora
- do not always cause disease, only when it leads to functional disequilibrium
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challenges pathogens must overcome to colonize
- maintain a reservoir
- gain access to a new host
- adhere to body surfaces
- invade deeper tissue
- evade the hosts defenses
- multiply in the host tissues
- exit the host and enter another
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common reservoirs
humans
animals
the environment
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humans as reservoirs
sick with the infection and showing symptoms
or
carriers and healthy but carrying the infection
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animals as reservoirs
- warm blooded and similar host-like environment
| - both domestic and wild animals
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zoonosis
when a human pathogen uses an animal as a reservoir
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environment as reservoir
soil, water, house dust
| ex. c. tetani spores in the soil
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transmission
a pathogen must be able to leave the reservoir and enter a new host body, or gain access to a host
requires a portal of entry
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portal of entry
way for pathogen to enter the body
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types of transmission
- respiratory droplet
- fomites
- direct body contact
- fecal-oral route
- arthropod vector- mechanical and biological
- airborne
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respiratory droplet transmission
- direct transmission from one host to another by droplets of respiratory secretions
- communicable transmission
- coughing, sneezing, laughing, or talking
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most common form of transmission
respiratory droplets
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fomites
inanimate objects
ex. cups, utensils, bedding, towels, chairs, tables
not reservoirs because will not maintain microbe for long period of time
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direct body
transmission that involves touching, kissing, or sexual intercourse
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fecal-oral route
pathogen is transmitted from infected feces to the mouth of new host
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ways fecal-oral transmission can occur
```
hand-to-hand contact
mouth-to-mouth
water
food
fomites
arthropod vectors
```
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vibrio cholerae
contaminate waters supply
when person drinks, they get diarrhea which contaminates bedding
healthcare worker cleans up patient and doesn't remove all of bacteria from hands prior to eating
transfers bacteria into mouth and gets sick
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arthropod vector
invertebrates with jointed legs that can be a vector or reservoir
ex. mosquitos, fleas, spiders, ticks
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mechanical vector
picks up pathogen on its body and carries from one place to another
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biological vector
- the arthropod is a stage in the microbes life
ex. plasmodium spends part of life cycle in the stomach of a mosquito causing it to be hungry. When the mosquito bites a human to get food, it regurgitates the protozoan into the human
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airborne
microbes can survive prolonged periods in the air and then are inhaled
can travel long distances in the air and there is no required close contact with another infected person
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pathogens main concern in establishing infection
protecting selves from phagocytes which are white blood cells that consume and destroy pathogens
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ways of evading host defenses
- capsule
- surface proteins that inhibit phagocytes from contact
- not being affected by enzymes produced by phagocytes
- antigenic variation
- biofilms
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antigenic variation
pathogen can change their outer surface proteins so the immune system is one step behind
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biofilm
many different cells working and living together
communicate through quarum sensing allowing them coordinate their activity and group together
gives them the benefits of multicelled organisms - share nutrients, only cells on outside responsible for protecting those inside
has pillar-like structures with channels between the cells for water, nutrient, and wastes
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exotoxin
produced and secreted as the cell grows
| will affect certain parts of the body
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endotoxin
part of the cell wall and released when the cell dies
| will affect entire body
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as the pathogen produces and releases their toxins...
the body reacts more strongly and becomes a hostile environment for the pathogen
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levels of defenses
surface
non-specific internal
specific internal
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surface level defenses
- structural barriers - ie skin
- mechanical barriers - ie mucociliary system
- biochemical barriers - ie lysozymes in tears
70
lactoferrin
example of biochemical barrier
found in secretions - inhibits biofilms by chelating iron which is needed by microbes for surface motility to aggregate into biofilms
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non-specific internal defenses
begin when the first line of defense has been overcome by invading microbe
include
- inflammation
- phagocytosis
- complement
- interferon
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inflammation
- body's reaction to injury or infection
| - pain, redness, heat, and swelling
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what activates and coordinate the other interior defenses
inflammation
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turning on inflammation
- happens by several different molecules such as bacterial by-products, complement fragments, histamine
- mediators trigger the capillaries to dilate which increases blood supply to inflamed tissue. The increased blood flow causes erythema. The endothelial cells of the capillary vessel allow leukocytes to leave the capillaries and enter the inflamed tissue. Edema and pain due to increased fluid and cells pushing on pain centers
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phagocytosis
- activation of leukocyte by inflammatory mediators
- chemicals draw leukocytes to site of infection
- recognition and opsonization
- once phagocyte has a hold of the microbe they ingest it
- phagocyte now kills the microbe and digests it
- phagocyte expels and indigestible debris
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macrophage
- phagocytes that produce granules which they release by degranulation
- granules are toxic and also used as inflammatory mediators
- attack any invader
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neutrophils
phagocytes designed to attack bacteria
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eosinophils
leukocytes that produce granules toxic to protozoans, fungi, and worms
not phagocytes
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chemotaxis
chemicals draw leukocytes to infected area
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opsonization
protein called opsonin attaches to the surface of the microbe and/leukocytes acting like apiece of double stick tape to allow the phagocyte to hold the microbe
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opsonin
linking molecules that bridge a leukocyte and microbe
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complement system
- set of 30 proteins that works as a cascade effect
- must be activated
- functions to produce inflammatory mediators, produce opsonins for phagocytosis, and form
membrane attack complex
- 2 pathways
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classical pathway
- activated by antigen-antibody complex
| - dependent on and interactive with our specific internal defenses
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antigen
molecule that provokes a response form a leukocyte
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antibody
protein molecule produced by B cells in response to a specific antigen
86
alternative pathway
- activated when 4 appropriate molecules come together on the surface of the cell
- does not require antigen-antibody complex
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membrane attack complex
multiple complement proteins set themselves on surface of cell in circle which punches a hold in the cell - lysing and killing it
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interferon
helps with viral infections
when a virion enters, the infected cell is triggered to produce and release interferon which contacts surrounding cells and tells them to produce anti-viral proteins. The infected cell is taken over by virion and produces new virions which move to surrounding cells which now contain anti-viral protein and will not synthesize new virions.
89
steps of interferon
1. virion attacks
2. host cell sends out interferon
3. interferon triggers anti-viral protein
4. new virions attack new host cells
5. anti-viral protein interferes with viral synthesis
90
problems with interferon
- toxic to heart, liver, kidneys, and red bone marrow
- only effective for short time
- causes nausea, fatigue, headache, vomiting, weight loss and fever
91
alpha interferon as therapy
for genital herpes and hep B and C
92
beta interferon as therapy
for slowing progression of MS
93
specific internal defenses are known as
our immune system
94
types of specific internal immunity
active
| passive
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active immunity
the development of B and T cells from a naturally occurring infection or response to a vaccine
96
passive immunity
only antibodies - take antibodies from one individual and inject into another who does not have these antibodies
ex. as mother nurses infant she passes her antibodies to them in breast milk
97
tasks of immune system
- recognize foreign invader
- activate entire system to prepare to fight
- response where the system eliminates or at lease contains the invader
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Humoral immunity
B cell immunity
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B cell recognition
the antibody on the surface of the B cell matches the surface receptor or antigen of the invading cell
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B cell activation
- B cell triggers production of plasma cells which produce the antibodies on the surface of the B cell and secrete them so they can float thorugh the body and and attach to other antigens
- B cells produce memory cells which will stay in the body and quickly combat any future identical invaders
101
B cell response
antibodies bind to antigen which is now a tag to have the antigen destroyed
102
Cell mediated immunity
T cell immunity
103
classes of T cells
T4 - helper
| T8
104
T4 cells
contains specific receptors on surface to recognize self cells
coordinate T cell activity with B cell activity
tell T8 cells what to do
105
T8 cells
become a suppressor or killer cell based on T4 instructions
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T cell recognition
T4 cells contain receptors to recognize self. If do not recognize cell as cell, recognize it an incador
107
T cell activation
The T4 cell tells the T8 cell to become a killer cell and look for tagged cells
T4 also triggers production of T memory cells for fighting identical future invading cells
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T cell response
T8 kills the tagged cells
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problems of the immune system
- immune system malfunctions and produces inappropriate or inadequate immune responses
110
hypersensitivity
- involve misdirected immune response where the immune system damages own human tissues
111
systemic allergic reaction
body releases histamines that cause blood vessels to dilate and brochial passageways to constrict. Within 20 min, rapid fluid loss form circulatory system leads to bp drop and even death
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whole agent vaccines include
inactivated
| attenuated
113
inactivated vaccines trigger
B cells
114
attenuated vaccines trigger
both B and T cells
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which type of whole agent vaccine requires multiple boosters
inactivated
116
purified antigen vaccines
specific and purified antigen
| can be piece of bacterial cell wall, viral capsid, specific toxin
117
best way to tell a microbe is dead
cannot divde to make a new cell
118
sterilization
destroying all microbial life including spores
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disinfection
reduce the number of pathogens to a levels where they pose no danger of disease - concerned only with pathogens not all microbes
120
antiseptics
killing microbes on our skin or other living tissue
121
microbiostatic
inhibiting growth
ex. refrigeration - inhibits growth does not kill the microbe
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microbiocidal
controlling microbes by killing them
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methods of controlling microbes
- heat
- cold
- radiation
- filtration
- drying
- chemicals
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heat for control
- can be moist or dry
- moist kills more readily
- ex. autoclaving, open flame
125
cold for control
- in general does not kill but freezing does kill some bacteria and eukaryotic celled microbes
- kills bacteria from outside in
- cytoplasm of eukaryote freezes and expands causing the cell to burst
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radiation as control
ex. UV light has wavelength of 265nm which is the size of bacterial DNA
can cause mutation
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filtration as control
removing the microbes from liquid or gas
effective but more time consuming and expensive than autoclaving
128
drying as control
removal of water form the cells which will inhibit a cells growth but not kill it
is used in food industry
129
chemical control
antibiotics
| germicide - can be disinfectants, antiseptics
130
pickling
lowers pH so microbes cannot grow
131
nitrites
prevents spoilage by clostridium botulinum
132
radiation for food processing
food subjected to gamma rays to kill pathogens in the food
| labeled cold pasteurized
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bioreactor
contain used to grow microbes in large quantities for biotechnology
can be regulated with appropriate O2, pH, and temp to ensure best growth
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bacillus thuringiensis
natural pesticide
135
pharmacology
the study o fdurgs
136
drugs
any chemicals that have a physiological effect on living things
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chemotherapeutic agents
drugs used to treat disease
138
antibiotics
metabolic products of one microbe that kill or inhibit the growth of others
139
antibacterial agents
used against bacterial infections
| produced in lab
140
antimycobacterial agents
designed against TB
141
antiviral agents
used against viral infections
142
most drugs are eliminated by
excretion, usually the urine
143
drug resistance
any genetic alteration that allows the microbe to resist the drug
can be from acquisition of a plasmid, a mutation, they may not have the target site of the drug, they may produce and enzyme that destroys the drug, they may be able to efflux the drug
144
drug spectrum
what pathogens the drug can kill
145
narrow spectrum drug
affects only a single microbial group and are best used the specific pathogen is known
146
broad spectrum drug
affects 2 or more microbial groups
| good when pathogen is unknown but bad because will more significantly alter the normal body flora
147
some modes of actions for drugs
- inhibit cell wall synthesis
- disrupt cell membrane
- inhibit protein synthesis
- inhibit folic acid synthesis
148
Impact of drugs that inhibit folic acid production on humans?
none - we ingest not produce our folic acid
149
which mode of action will impact humans most in drugs?
disrupting cell membrane because will also impact our cells
150
epidemiology
the study of when and where diseases occur and hos they are transmitted in the human population
generate info needed to prevent and control disease
151
epidemics
patterns of disease transmissions that affect many members of a population within a short time
152
pandemics
epidemics that spread worldwide
153
ex of epidemic
cholera
| polio
154
ex of pandemic
AIDS
155
endemic
disease that is always present in a population at about the same level
156
ex of endemic
gonorrhea
157
sporadic disease
occur only occasionally in a population
158
ex of sporadic disease
tetanus
159
How do epidemiologist study disease
they gather info in the forms of surveys, questionnaires, interviews, and hospital records
160
nosocomial infection
acquired while hospitalized
161
why are nosocomial infections inevitable
- patients are immunocompromised
- medical procedures are invasive
- antibiotic resistance in increasing
162
biggest concerns of the public health department
- diminishing reservoirs
| - interfering with transmission
163
areas of control for public health department
```
water
food
hand washing
insect control
immunizations
```
164
control of water
adequate sewage treatment systems and clean water supply
165
clean food
inspection of restaurants, grocery stores with deli departments
pasteurizing food
166
reasons for emerging infectious disease
- what appears to be new disease is realy modification of old one due to gentic alterations - small enough that they do not destroy the pathogen but creates the inability for our antibodies to recognize
- changes in the environment of a pathogen - can easily move from continent to continent giving it a whole new environment which is not used to dealing with
