Infections CH 14. Flashcards
What does symbiosis mean
to live together
Distinguish between mutualistic, commensal, and parasitic relationships.
Mutalistic- benefits, bacteria in the colon, its warm and moist.
Commensal- no benefits or harm, Stappylococcus or skin
Parasitism- Benefits organism 1 harms organism 2 is bacteria found in the lungs and TB
What does a parasitic bacterium do in the body?
*Cause damage to body while host thrives
What are resident microbiota and transient microbiota? What type of relationship do most microbes have with humans?
- Resident- Present lifelong in humans (Commensal Relationship; nor harms, nor benefits human)
Transient-only present for hours, days or months
About how many species of microbes occur in our GI tract
1000
How does the environmental difference between the upper GI tract and lower GI tract influence the type of resident microbes that are present?
dozens of species in the upper GI tract, and mostly strict anaerobes and sometimes facultative anaerobes are also resident in the lower GI tract.
What is microbial antagonism
Microbial antagonism: preventing the growth of pathogens by competition with our normal resident microbes for different limited resources
What are opportunistic pathogens
Opportunistic pathogens: normal microbiota that cause disease only under certain circumstances
What are 3 ways that a normal resident microbe can become an opportunistic pathogen?
1) Com-positional changes- Reduce microbial antagonism
2) Unrealistic for occurrence of resident microbes
3 )Suppression of ones immune system such as stress and malnutrition
What are reservoirs of infection Essay question…
sites where pathogens are maintained and are a source of infection
What are the 3 types of reservoirs of infection?
human,animal,nonliving *
What are zoonotic diseases
When animals give humans a diseases Rabies
What are 3 ways that a human can acquire a zoonotic disease
direct contact with animal or its waste eating infected animals arthropod vectors
What are 3 examples of animal reservoirs and the disease agent that they harbor
Human- Active disease- TB
Nonliving contamination- by feces or urine- Tetanus botulism
Animal-ringworm
Give examples of 2 diseases transmitted by a human carrier.
Tb and syphilis, HIV
What do nonliving reservoirs generally refer to? How do these reservoirs end up harboring infectious agents?
Soil water, Contamination by feces or urine
Name one infectious agent present in a nonliving reservoir.
Tetanus , botulism
What does contamination mean
Presence of microbes in or on the body
What does infection mean? Does an infection always result in a disease?
Successful invasion of a host by a pathogen. NO
What is a portal of entry refer to in the infection process?
Pathogens that enter the body at several sites*
What are the 4 portals of entry in humans
Skin, mucus membranes, respiratory tract, parental
What is the major portal of entry in humans for disease agents? Which site is most common?
mucous membrane, respiratory tract
What is the difference between a sign of a disease and a symptom of a disease? Give examples of each.
symptoms are subjective characteristics.
signs are objective manifestations of disease.
What is a syndrome? What does asymptomatic mean
a group of symptoms ans signs, Asymptomatic = no symptoms
