Exam 4 - Chapter 16 Flashcards
microbiome def.
all prokaryotic and eukaryotic microorganisms and their genetic material that are associated with a certain organism or environment
transient microbiota
commensal, present for days/weeks/months
normal microbiota
permanently colonize the host, does not cause disease under normal conditions
Normal microbiota are usually ________
mutualists
What factors affect the distribution and composition of normal microbiota? (4)
Nutrients
Physical and chemical factors
Host defenses
Mechanical factors
microbial antagonism (competitive exclusion) def.
a competition between microbes
Normal microbiota protect the host by:
a) competing for nutrients
b) producing substances harmful to invading microbes
c) affecting pH and available oxygen
d) all of the above
d) all of the above
other benefit of microbes:
produce vitamins
digest materials that humans cannot
broad-spectrum antibiotic def.
one that kills many different types of bacteria
pathology def.
the study of disease
etiology
the cause of a disease
pathogenesis
the development of disease
infection def.
invasion or colonization of the body by pathogens
disease def.
an abnormal state in which the body is not performing normal functions
symptoms def.
changes in body function that are felt by a patient as a result of disease
»subjective
»patient must describe symptoms
signs def.
changes in a body that can be measured or observed as a result of disease
syndrome def.
a specific group of signs and symptoms that accompany a disease
group of symptoms
communicable disease def.
a disease that is spread from one host to another
contagious disease def.
diseases that are easily and rapidly spread from one host to another
noncommunicable disease def.
a disease that is not spread from one host to another
herd immunity def.
immunity in most of a population
incidence def.
number of people who develop a disease during a particular time period
prevalence def.
number of people who develop a disease at a specified time, regardless of when it first appeared (both old and new cases)
sporadic disease def.
disease that occurs only occasionally
endemic disease def.
disease constantly present in a population
epidemic disease def.
disease acquired by many people in a given area in a short time
pandemic disease def.
worldwide epidemic
outbreak def.
occurence of disease in excess of what would normally be expected in a defined community, geographical area or season
acute disease def.
symptoms develop rapidy but the disease lasts only a short time
chronic disease def.
symptoms develop slowly or have been ongoing
subacute disease def.
intermediate between acute and chronic
latent disease def.
causative agent is inactive for a time but then activates and produces symptoms
subclinical disease def.
no noticeable signs or symptoms (inapparent infection)
local infection def.
pathogens are limited to a small area of the body
systemic infection def.
an infection throughout the body
focal infection def.
infection that began as a local infection and spread to other confined areas of the body
sepsis def.
toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins, from a focus of infection
blood poisioning from systemic infection
rapid loss of blood pressure
primary infection def.
acute infection that causes the initial illness
secondary infection def.
opportunistic infection after a primary (predisposing) infection
incubation period def.
interval between initial infection and first signs and symptoms
prodromal period def.
short period after incubation; early, mild symptoms
period of illness def.
disease is most severe
period of decline def.
signs and symptoms subside
period of convalescence def.
body returns to its prediseased state
human reservoirs def.
carriers may have inapparent infections or latent diseases
humans infected by pathogens that exist on or within the human body
animal reservoirs def.
zoonoses are diseases transmitted from animals to humans
domesticated and wild animals infected by pathogens
nonliving reservoirs examples(2)
soil and water
reservoirs def. (epid)
reservoir is where an infectious agent or a parasite can live, grow, and reproduce continual sources of infection
transmissions of disease (3)
contact transmission
vehicle transmission
vector transmission
contact transmissions (3)
direct contact
indirect contact
droplet transmission
direct contact transmission def.
requires close association with between the infected person and a susceptible host
indirect contact transmission def.
spreads to a host by a nonliving object called a fomite
droplet transmision def.
transmission via airborne droplets less than 1 meter
vehicle transmission def.
transmission by an inanimate reservoir
inanimate reservoir (3)
Vehicle Transmission
waterborne
foodborne
airborne
vector transmission
infection transmission via second population (vector)
vector sources
fleas, ticks, mosquitoes
vector transmission two methods
mechanical transmission
biological transmission
mechanical transmission def.
arthropod carries pathogen on its feet
biological transmission
pathogen reproduces in the vector; transmitted via bites or feces
health-care associated infections (HAI)
infections acquired while receiving treatment in a health care facility (nosocomial infections)
compromised host def.
an individual whose resistance to infection is impaired by disease, therapy, or burns
epidemiology def.
study of where and when diseases occur and how they are transmitted in populations
epidemiologists are:
are health professionals who identify the causes of a disease, those at risk of contracting it, and how to stop or control its spread.
Centers for Disease Control and Prevention (CDC)
collects and analyzes epidemiological information to the U.S
morbidity def.
rate of disease
mortality def.
deaths from notifiable disease
