(exam 2) chapter 14 principles of disease and epidemiology Flashcards
what is pathology?
the study of disease
what is etiology?
the cause of a disease
what is infection?
invasion or colonization of the body by pathogens
what is pathogenesis?
the development of disease
what is disease?
(the result of infection) an abnormal state in which the body is not performing normal functions
what are three things we know about the human microbiome?
1) begins to be established in utero (starts in intestines)
2) rapidly changes during first three years of life (so environment is very important)
3) remains throughout entire life (contributes to health and disease; childhood exposure to microbes helps immune system development)
what is normal microbiota?
permanently colonize the host and do not cause disease under normal conditions
what is transient microbiota?
may be present for days, weeks, or months
what is microbial antagonism (competitive exclusion) ?
is a competition between microbes
what are three ways that normal microbiota protect the host by?
1) completing for nutrients
2) producing substances harmful to invading microbes
3) affecting pH and available oxygen
what do normal microbiota prevent?
prevent colonization of host by pathogens
what are symbiosis?
a relationship between two organisms where at least one is dependent on the other
what is commensalism?
(symbiosis) one organism benefits, the other is unaffected
what is mutualism?
(symbiosis) both organisms benefit
what is parasitism?
(symbiosis) one organism benefits at the expense of another (pathogens)
what are two possible reasons that the type of symbiotic relationship can change?
1) heavy antibiotic regimen
2) changes in the immune system
Some normal microbiota are opportunistic pathogens which means what?
it means that some normal microbiota have the potential to cause disease if the environmental conditions change (such as a weakened immune system)
what is etiology?
the cause of a disease
what is Koch’s postulates?
four criteria for establishing a causative relationship between a microbe and an infectious disease (framework for studying disease etiology)
what are the four Koch’s postulates?
1) pathogen must be present and the same in every case of the disease
2) it must be isolated from the diseased host and grown in pure culture
3) when grown in pure culture it must case the disease when inoculated into a healthy, susceptible animal
4) must be isolated from the inoculated animal and shown to be the original organism
what are three exceptions to Koch’s postulates?
1) some pathogens can cause several disease conditions
2) some pathogens only cause disease in humans so we cannot test on animals
3) some microbes have never been cultures bc they are hard to grow outside the host organism
what are symptoms?
subjective; changes in body function that are felt by a patient as a result of diease
headaches, fatigue, muscle aches, nausea, and chills are all examples of what?
symptoms
what are signs?
objective; changes in a body that can be measured or observed as a result of disease
fever, vomiting, increased heart rate are all examples of what?
signs
what is a syndrome?
a specific group of both signs and symptoms that accompany a disease
what are the two main groups of infectious diseases?
communicable diseases and noncommunicable diseases
what are communicable diseases?
a disease that is spread from one host to another
what are contagious diseases?
subcategory of communicable diseases; diseases that are easily and rapidly spread from one host to another
what are noncommunicable diseases?
a disease that is not spread from one host to another
what is incidence?
number of people who develop a disease during a particular period of time (newly infected)
what is prevalence?
number of people who have a disease at a specified time period, regardless of when it first appeared (takes into account BOTH old and new cases)
what is a sporadic disease and what is an example?
disease that occurs only occasionally (typhoid fever)
what is an endemic disease and what is an example?
disease constantly present in a population (the common cold)
what is an epidemic disease and what is an example?
disease acquired by many people in a given area in a short time (influenza and AIDS)
what is a pandemic disease and what is an example?
a worldwide epidemic (COVID-19, influenza, and AIDS)
what is an acute disease and what is an example?
symptoms develop rapidly but the disease only lasts a short period of time (influenza)