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150 Cards in this Set

  • Front
  • Back
What is pathology?
the scientific study of disease
What is etiology?
the study of the cause of a disease
What is pathogenesis?
Development of a disease
What is an infection?
colonization of the body by pathogens, or the presence of a microbe in a part of the body where it is not normally found.
What is a disease?
an abnormal state in which the body is not functioning normally
Do normal microbiota permanently or temporarily colonize the host?
Permanently
How many cells is the body made up of?
10 trillion
How many bacteria does the body contain?
100 trillion
Is normal microbiota found in all areas of the body or only certain regions?
Only certain regions
How long is transient microbiota present?
days, weeks or months
How does normal microbiota prevent harmful organisms from overgrowing?
1. occupying niches that pathogens might occupy

2. producing acids

3. producing bacteriocins (compounds that kill other bacteria)
What are probiotics?
live microbes applied to or ingested into the body, intended to exert a beneficial effect.
What is symbiosis?
The relationship between the normal microbiota and the host
In symbiosis, what is commensalism?
one organism is benefited and the other is unaffected
In symbiosis, what is mutualism?
both organisms benefit
In symbiosis, what is parasitism?
one organism is benefited at the expense of the other
In symbiosis, are many of the normal microbiota commensalism, mutualism or parasitism?
Commensalism and Mutualism
In symbiosis, are disease causing organisms commensalism, mutualism or parasitism?
parasitism
Can some normal microbiota be opportunistic pathogens?
Yes
Do the opportunistic pathogen normal microbiota cause disease in healthy individuals?
No
Can opportunistic pathogen normal microbiota cause disease if they colonize in an area where they are not normally found?
Yes
Do individuals with compromised immune systems often become infected with opportunistic pathogen normal microbiota?
yes
Can Koch's Postulates be used to prove the cause of an infectious disease?
yes
In the case of proving the cause of an infectious disease with Koch's Postulates does the same pathogen need to be present in every case of the disease?
yes
In the case of proving the cause of an infectious disease with Koch's Postulates does the pathogen need to be isolated from the diseased host and grown in pure culture?
yes
In the case of proving the cause of an infectious disease with Koch's Postulates does the pathogen from the pure culture need to cause the disease when it is innoculated into a healthy, susceptible laboratory animal?
yes
In the case of proving the cause of an infectious disease with Koch's Postulates does the pathogen need to be isolated from the innoculated animal and must be shown to be the original organism?
yes
What are the 4 exceptions to Koch's Postulates?
1. some microorganisms have unique culture requirements and cannot be cultured on artificial media

2. Multiple organisms can often cause the same disease signs and symptoms

3. Some species can cause multiple different disease conditions

4. moral and ethical considerations come into play when trying to ascertain which organisms are involved in causing diseases that only affect humans.
What is a symptom?
a subjective change in body function that is felt by a patient as a result of a disease.
what is a sign?
an objective change in a body that can be measured or observed as a result of disease.
What is a syndrome?
a specific groups of signs and symptoms that always accompany a disease
What is a communicable disease?
a disease that is directly or indirectly spread from one host to another.
What is a contagious disease?
a disease that is EASILY spread from one host to another
What is a non-communicable disease?
a disease that is not transmitted from one host to another.
In regards to occurence of disease, What is an incidence?
fraction of a population that contracts a disease during a specific time period
In regards to occurrance of disease, what is prevalence?
fraction of a population having a specific disease at a given time.
In regards to occurrance of disease,what is sporadic disease?
a disease that occurs only occasionally in a population
In regards to occurrance of disease, what is endemic disease?
a disease that is constantly present in a population.
In regards to occurrance of disease, what is an epidemic disease?
a disease acquired by many hosts in a given area in a short time
In regards to occurrance of disease, what is a pandemic disease?
worldwide epidemic
In regards to severity or duration of a disease, what is an acute disease?
develops rapidly but is short-lived
Give an example of an acute disease.
Influenza
In regards to severity or duration of a disease, what is a chronic disease?
develops slowly and persists for long periods
Give an example of a chronic disease.
TB
In regards to severity or duration of a disease, what is a subacute disease?
Intermediate between acute and chronic
In regards to severity or duration of a disease, what is a latent disease?
a disease with a period of no symptoms when the patient is inactive.
Give an example of a latent disease.
shingles
In regards to severity or duration of a disease, what is herd immunity?
when most of a population is immune to a pathogen, non-immune individuls are less likely to come into contact with an individual that is infected.
In regards to the extent of host involvement, what is a local infection?
pathogens limited to a small area of the body.
In regards to the extent of host involvement, what is systematic (generalized) infection?
microorganisms or their products are spread throughout the body via blood or lymph.
In regards to the extent of host involvement, what is focal infection?
systematic infection that began as a local infection
In regards to the extent of host involvement, what is bacteremia?
bacteria in the blood
In regards to the extent of host involvement, what is septicemia?
growth of bacteria in the blood
In regards to the extent of host involvement, what is toxemia?
toxins in the blood
In regards to the extent of host involvement, what is viremia?
viruses in the blood
In regards to the extent of host involvement, what is primary infection?
acute infection that causes the inital illness
In regards to the extent of host involvement, what is secondary infection?
opportunistic infection after a primary infection
In regards to the extent of host involvement, what is sub-clinical infection?
no noticeable signs or symptoms.
What are the steps to the patterns of disease? (5)
1. a reservoir must exist

2. the pathogen must be transmitted to a sucseptible host

3. the pathogen invades the host and multiplies

4. The pathogen injures the host

5. The illness ends when:
a. the host dies
b. the host's immune system destroys the pathogen.
What makes the body more susceptible to disease? (7)
1. short urethra in females

2. inherited traits such as the sickle-cell gene

3. climate and weather

4. fatigue

5. age

6. lifestyle

7. chemotherapy
In order, what are the 5 periods of the development of a disease?
1. Incubation period

2. prodromal period

3. period of illness

4. period of decline

5. period of convalescence
In regards to the development of a disease, what is the incubation period?
time between initial infection and the appearance of signs or symptoms.
In regards to the development of a disease, what is the prodromal period?
early mild symptoms of the disease appear; not all diseases go through this period
In regards to the development of a disease, what is the period of illness?
1. the disease is most acute at this time

2. overt signs and symptoms appear.

3. the number of WBC's may increase or decrease.

4. the host's immune response usually triumph over the pathogen to end the period of illness. If not, the host dies.
In regards to the development of a disease, waht is the period of decline?
signs and symptoms disappear
In regards to the development of a disease, what is the period of convalescence?
the host returns to its pre-illness state
During which stage of the development of a disease can the disease be spread?
During all stages
What are reservoirs of infection?
continual sources of infection
Are reservoirs of infection living or non-living?
both
Carriers of human reservoirs may have what?
inapparent infections or latent infections
Carriers of animal reservoirs may be able to transmit to humans. T or F?
True
Nonliving reservoirs are in such places as...?
Soil, water, etc.
In regards to transmission of disease, what is direct contact transmission?
requires close association between an infected individual and a susceptible host. Also-known-as person to person transmission.
In regards to the development of a disease, give an example of direct contact transmission.
touching, kissing and sexual intercourse.
Can pathogens be passed from animal to human through direct contact?
yes
In regards to the development of a disease, what is an indirect contact transmission?
the pathogen is spread from its reservoir to a susceptible host via a non-living object.
In regards to the development of a disease, give an example of indirect contact transmission.
tissues, cups, money, et.
In regards to the development of a disease, what is droplet transmission?
transmission via airborne droplets that travel less than one meter from the reservoir to the new host. This is different from airborne transmission.
In regards to the development of a disease, give an example of droplet transmission.
coughing, sneezing, talking
What is vehicle transmission?
transmission by an inanimate reservoir (food, water, air, body fluids)
In regards to vehicle transmission, what is waterborne transmission?
normally a result of water being contaminated by sewage.
In regards to vehicle transmission, what is foodborne transmission?
normally the result of foods being undercooked, poorly stored/refrigerated or handled in unsanitary ways.
In regards to vehicle transmission, what is airborne transmission?
transmission by airborne droplets that travel more than one meter from the reservoir to the new host.
In regards to vehicle transmission, give an example of airborne transmission.
Dust, certain fungal spores, and the fine spray that accompanies sneezes and coughs.
What are vectors?
arthropods, especially fleas, ticks and mosquitos
In regards to vectors, what is mechanical transmission?
arthropods carry pathogens on their feet or other body parts
In regards to vectors, what is biological transmission?
pathogen reproduces inside the vector.
What is a nosocomial Infection?
It's a hospital aqcuired infection.
What percentage of hospital patients acquire nosocomial infections?
5-15%; about 2 million per year; 100,000 die as a result
Are some nosocomial pathogens antibiotic resistant?
yes
what is a compromised host?
a host whose resistance to infection is impaired by disease, therapy or burns
What are conditions that can compromise the host?
broken skin, broken mucuous membranes, or a suppressed immune system
How are nosocomial infections controlled?
1. always use aseptic technique

2. Properly handle contaminated materials

3. frequent and thorough hand-washing

4. education of staff, patients and visitors

5. appropriately use isolation wards and rooms

6. make sure to thoroughly clean/disinfect rooms, sinks, tubs, toilets, etc. between patients

7. prescribe antibiotics only when appropriate and necessary

8. avoid invasive procedures if possible

9. minimize the use of immunosuppressive drugs
What are emerging infectious diseases?
disease that are new or changing, increasing in incidence or shoing a potential to increase in the near future.
What can an emerging infectious disease be caused by?
a virus, a bacterium, a fungus, a protozoan or a helminth
What are contributing factors to emerging infectious diseases?
1. evolution of new strains

2. innapropriate use of antibiotics/pesticides

3. changes in weather patterns/global warming

4. modern transportation

5. Ecological disaster/war/expanding human settlement

6. Animal control measures

7. Public health failure
Give an example of an emerging infectious disease caused by evolution of new strains
V. cholerae
Give an example of an emerging infectious disease caused by innapropriate use of antibiotics/pesticides.
antibiotic resistant strains
Give an example of an emerging infectious disease caused by changes in weather patters/global warming.
Hantavirus
Give an example of an emerging infectious disease caused by modern transportation.
West Nile Virus
Give an example of an emerging infectious disease caused by ecological disaster/war/expanding human settlement.
Coccidioidomycosis
Give an example of an emerging infectious disease caused by animal control measures.
Lyme Disease
Give an example of an emerging infectious disease caused by public health failure.
Diphtheria
What is epidemiology?
the study of where and when diseases occur and how they are transmitted in populations
What does the CDC do?
collects and analyzes epideiological information in the US.
Who publishes morbidity and mortality weekly report?
CDC
What is morbidity?
incidence of a specific notifiable disease.
what is mortality?
deaths from notifiable diseases.
what is a morbidity rate?
number of people affected in relation to the total population in a given time period.
what is a mortality rate?
number of deaths from a disease in relation to the total population in a given time period.
Are viruses inert when not within a host cell?
yes
Do viruses require a living host cell to multiply?
yes
Are viruses obligate intracellular parasites?
yes
Do viruses contain DNA, RNA or both?
They can contain either/or not both at the same time.
Do viruses have an ATP generating mechanism?
no
what do viruses have surrounding the nucleic acid?
protein coat
what are some viruses also enclosed by?
an outer lipid envelope
Do viruses have metabolic activity?
little or no activity
How do viruses multiply inside living cells?
by using the host cells own enzymes, nucleic acids, amino acids
What is a host range?
the range of host cells the virus can affect
How is the host range of a virus determined?
by specific host attachment sites and cellular factors necessary for viral multiplication.
In regards to host range, what do the attachment sites include?
cell walls, fimbriae, flagella, and plasma membrane proteins.
What are bacterial viruses called?
bacteriophages or phages
What does the viral size range from?
20 to 1000 nm in length.
What is a virion?
a single, mature, complete, infectious viral particle.
What is the primary genetic material in a given spiecies of a virus?
DNA or RNA
Are the nucleic acids in viruses single or double stranded?
can be either.
Is the nucleic acid in a virus linear or circular?
can be either.
What is a capsid?
protein coat surrounding the nucleic acid of a virus
What are the subunits that the capsid is comprised of called?
capsomers
Are capsomers comprised of proteins that are the same or different?
Can be composed of proteins that are the same or different
In regards to viruses what is an envelope?
lipid layer external to the capsid
Does the viral envelope contain proteins and carbohydrates?
yes
Can the viral envelope become covered with "spikes"?
yes
What are the "spikes" that may or may not cover a viral envelope composed of?
glycoproteins that project from the surface of the envelope
The glycoproteins on the viral envelope, can they sometimes serve as attachement points for binding to host cells?
yes
When a host is infected with a virus what does it stimulat the host to do?
create antibodies that will recognize and bind to viral proteins
do some protein viruses frequently mutate?
yes
What allows viruses to infect you more than once?
mutation
What are the four shapes viruses can be classified on the basis of their structure?
1. Helical Viruses

2. Polyhedral (many-sided) viruses

3. Enveloped Viruses

4. Complex viruses
What are the 3 things viruses are grouped into families based on?
1. nucleic acid type

2. replication strategy

3. morphology
What do viral family names end in?
-viridae
What do viral genus names end in?
-virus
What is a viral species?
a group of viruses sharing the same genetic information and ecological niche
are viral subspecies designated by a number?
yes
Must viruses be grown in living cells?
yes
What are supplied by the host cell to synthesize viral proteins and enzymes?
Ribosomes, tRNA, amino acids, ATP and enzymes.
What are bacteriphages?
DNA viruses that multiply by two alternative mechanisms
What are the 2 alternative mechanisms bacteriophages use?
the lytic cycle and the lysogenic cycle
Explain the lytic cycle.
1. Attachment: Phage attaches by its tail fibers to the host cell.
2. Penetration: Phage lysozyme opens the cell wall, and its tail sheath contracts to force the tail core and viral DNA into cell.
3. Biosynthesis: Phage DNA directs production of phage DNA and proteins
4. Maturation: spontaneous assembly of phage components into virions
5. release: phage lysozyme breaks cell wall to release new virions