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92 Cards in this Set
- Front
- Back
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Pathology |
- scientific study of disease - first concerned with the cause - second it is concerned with the manner in which a disease develops - third pathology is concerned with the structural and functional changes brought by disease and with their final effects on the body |
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Etiology |
- cause of the disease |
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Pathogenesis |
- the manner in which the disease develops |
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Infection |
- is the invasion or colonization of the body by pathogenic microorganisms - may exist in the absence of detectable disease - the presence of a particular type of microorganism in a part of the body where it is not normally found |
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Disease |
- occurs when an infeciton results in any change from state of health - abnormal state in which part or all of the body is not properly adjusted or incapable of performing its normal function |
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Human Microbiome Project |
- analyze microbial communites called microbiomes that live in and on the human body - goal is to determine the relationship between changes in the human microbiome and human health and disease |
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Normal Microbiota |
- microorganisms that establish more or less permanent resident but that do not produce disease under normal conditions |
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Transient Microbiota |
- may be present for several days, weeks, or months, and then disappear |
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Normal Microbiota |
- nutrients, physical and chemical factors, defenses of the host, and mechanical factors dtermine the distribution and composition of the normal microbiota |
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Physical and Chemical Factors |
- affect the growth of microbes and thus growth and composition of normal microbiota - amount these, are temperature, pH, available oxygen and carbon dioxide, salinity, and sunlight
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Competitive Exclusion/Microbial Anatagonism |
- normal microbiota can benefit the host by preventing the overgrowth of harmful organisms - involves competition among microbes - one consequence of this competition is that the normal microbiota protect the host cell against colonization by potentially pathogenic microbes by competing for nutrients, producing substances harmful to the invading microbes, and affecting conditions such as pH and available oxygen |
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Symbiosis |
- the relationship between the normal microbiota and the host - relationship between two organisms in which at least one organisms is dependent on the other |
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Commensalism |
- type of symbiosis where one of the organisms benefits, and the other is unaffected - many of the microorganisms that make up our normal microbiota are commensalism |
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Mutualism |
- type of symbiosis that benefits both organisms |
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Parasitism |
- another kind of symbiosis - one organisms benefits by deriving nutrients at the expense of the other - many disease causing bacteria are parasites |
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Opportunistic Pathogens |
- microbes that ordinarly do not cause disease in thier normal environment in a healthy person but may do so in a different environment - possess other features that contribute to their ability to cause disease - may be found in locations in or on the body that are some what protected from the body's defense, and some are resistant to antibiotics |
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Koch's Postulates |
- german physician who played a major role in establishing that microorganisms cause specific diseases - showed that a specific infectious disease is caused by a specific microorganism that can be isolated and cultured on artificial media |
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Koch's Postulates |
1) the same pathogen must be present in every case disease 2) the pathogen must be isolated from the diseased host and grown in pure culture 3) the pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal 4) the pathogen must be isolated from the inoculated animal and must be shown to be the original organism |
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Exceptions to Koch's Postulates |
- some microbes have unique culture requirements and cannot be grown on artifical media - some infectious diseases are not clear cut and can present the same symptoms of pathogen - some pathogens can cause several disease conditions |
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Symptoms |
- changes in body function - ex: pain and malaise (body discomfort) - subjective changes are not apparent to an observer |
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Signs |
- which are objective changes the physician can observe and measure - ex: lesions, swelling, fever, and paralysis |
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Syndrome |
- a specific group of symptoms or signs that accompany a particular disease |
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Communicable Disease |
- any disease that spreads from one host to another, either directly or indirectly |
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Contagious Disease |
- disease that are easily spread form one person to another |
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Noncommunicable Disease |
- not spread form one host to another - caused by microorganisms that normally inhabit a body and only occasionally produce disease or by microorganisms that reside outside the body and produce disease only when introduced into the body |
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Incidence |
- the number of people in a population who develop a disease during a particular period of time - it is an indicator of the spread of the disease |
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Prevalence |
- the number of poeple in a population who develop a disease at a sepcific time, regardless of when it first appeard - takes into account both old and new cases - indicator of how seriously and how long a disease affects a population |
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Sporadic Disease |
- a particular disease occurs only occasionally |
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Endemic Disease |
- a disease constantly present in a population |
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Epidemic Disease |
- if many people in a given area acquire a certain disease in a relatively short period of time |
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Pandemic Disease |
- an epidemic disease that occurs worldwide |
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Acute Disease |
- one that develops rapidly but lasts only a short time |
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Chronic Disease |
- develops more slowly and the body's reaction may beless severe but the disease is likely to contiue to recur for long periods |
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Subacute Disease |
- a disease that is intermediate between acute and chronic |
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Latent Disease |
- one in which the casusative agent remain inactive for a time but then becomes active to produce symptoms of the disease |
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Herd Immunity |
- when many immune people are present in a community |
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Local Infection |
- one in which the invading miroorganism are limited to relatively small area of the body |
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Systemic Infection |
- microorganism or their products ar spread thorugh out the body by the blood or lymph |
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Focal Infection |
- often agents of a local infection enter a blood or lymph vessel and spread to another part of the body where they are confined to specific areas of the body - focal infections arise from infectious areas such as the teeth, tonsils, or sinuses |
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Sepsis |
- toxic inflammatory condition arising form the spread of microbes specially bacteria or their toxins form a focus of infection |
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Septicemia |
- blood poisining - systemic infection arising from the multiplication of pathogens in the blood - common example of sepsis |
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Bactermia |
- the presence of bacteria in the blood |
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Toxemia |
- refers to the presence of toxins in the blood |
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Viremia |
- refers to the presence of viruses in the blood |
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Primary Infection |
- an acute infection tht casues the intial illness |
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Secondary Infection |
- one casued by an opportunistic pathogen after the primary infection has weakend the body's defense |
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Subclinical Infection |
- one that does not cause any noticeable illnes |
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Predisposing Factors |
- makes the body susecptible to a disease and may alter the course of the disease - ex: gender, genetic background, climate, and weather, inadequate nutrition, fatigue, age, environment, habits, chemotherapy, emotional disturbances |
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Incubation Period |
- interval betweeen the intial infection and the first appearance of any signs or symptoms - there are no symptoms or signs present - time of incubation depends on the specific microorganisms involved, its virulence, the number of infection microorganisms, and the resistance of the host |
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Prodromal Period |
- realtively short period that follows the period of incubation in some disease - characterized by early, mild symptoms of disease, such as general aches and malaise |
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Period of Illness |
- the disease is most severe - period exhibits overt signs and symptoms of disease such as fever, chills, muscle pain - during the period illness, the number of white blood cells may increase or decrease |
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Period of Decline |
- the signs and syptoms subside - the fever decreases and the feeling of malaise diminishes - patient is vulnerable to secondary disease |
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Period of Convalescence |
- the periosn reagains strenth and the body returns to ists prediseased state - recovery has occurred |
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Reservoir of Infection |
- source that can be either a living organims or inainmate object that provides a ptheogen with adquate conditons for survival and mutliplication and an opportunity for transmission |
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Human Reservoir |
- people harbor pathogens and transmit them directly or indirectly to others |
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Carriers |
- people harbor pathogens and transmit them to others without exhibiting any signs of illness - important living reservoirs of infection - some have inapparent infections for which signs or symptoms are never exhibited |
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Animal Reservoirs |
- both wild and domestic animals are living reservoirs of microorganisms that casuse human disease |
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Zoonoses |
- desease that occur primarly in wild and domestic animsla and can be trasmitted to humans |
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Tranmission of Zoonoses |
- by direct contact with infected animals - by direct contact with domestic pet waste - by contamination of food and water - by air from contaminated hides, fur, or feathers - by consuming infecting animals products - by insect vectors |
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Nonliving Reservoirs |
- two major nonliving reservoirs are soil and water - food improperly prepared or stored - soil harbors such pathogens as fungi - water can be contaminated by feces of humans and other animals |
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Contact Transmission |
- the spread of agent of disease by direct contact, indirect contact, or droplet transmission |
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Direct Contact Tranmission |
- known as person to person transmission - the direct transmission of an agent by physical contact between its source and susceptible host - no intermediate object involved |
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Indirect Contact Transmission |
- occurs when the agent of the disease is transmitted form its reservoir to a susepctible host by means of a nonliving object |
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Fomite |
- term for any nonlivng object involved in the spread of an infection |
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Droplet Transmission |
- mirobes are spread in droplet nuclei (mucus droplets) that travel through only short distances - discharged into the air through coughing, sneezing, laughing, or talking |
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Vehicle Trasmission |
- the transmission of disease agents by a medium, such as water, food, or air - other media include fluids, drugs, and intravenous fluids |
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Waterborne Transmission |
- pathogens are usually spread by water contamination with untreated or poorly treated sewage - |
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Foodborne Transmission |
- pathogens are generally transmitted through foods that are incompletely cooked, poorly refrigirated, or prepared under unsanitary conditons |
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Ariborne Transmission |
- refers to the spread of agents of infeciton by droplet nuclei in dust that travel more than 1 meter form the reservoir host |
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Vectors |
- animals that carry pathogens form one host to another - arthropods vectors transmit disease by two general methods: mechanical and biological |
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Mechanical Trasnmission |
- the passive transport of the pathogens on the insect's feet or other body parts |
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Biological Transmission |
- active process and is more complex - arthropod bites an infected person or animal and ingest some of the infected blood - pathogens then reproduce in the vectors and the increase in the number of pathogens increases the possibility that they will be transmitted to another host |
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Nosocomial Infection |
- it is acquired as a result of a hospital stay - the 8th leading cause of death in the US |
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Health Care Associated Infection |
- used to introduce infeciton acquired in settings other than just hospital |
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Nosocomial Infection Factors |
1) microorganisms in the hospital environment 2) the compromised status of the host 3) the chain of transmission in the hospital |
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Compromised Host |
- one whose resistance to infection is impaired by diesease, therapy, or burns - two principal conditions can compromise the host: broken skin or mucous membranes, and a suppressed immune system |
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Principal routes of transmission for nosocomial infections |
1) direct contact transmission from hospital staff to patient and from patient to patient 2) indirect contact transmission through fomites and hospital's ventilation system |
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Control of Nosocomial Infections |
- usng aspectic techinques - handling contaminated materials carefully - insisting on frequent handwashing - educating staff members on basic infection control measures - using isolation rooms and wards - physicians can help improve patients resistance to infections by prescribing antibiotics only when necessary |
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Emerging Infectious Disease |
- are ones tht are new or changing, showing an incrnease in incidence in the recent past, or potential to increase in the near future - can be caused by virus, bacterium, a fungus, protozoan, or a helminth |
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Factors Contributing to Emergent Infectious Diseases |
- new strains may result form gentic recombination between organisms - a new serovar may result from changes in or the evolution of existing microorganism - the widespread and use of antibiotics and pesticides encourage the growth of more resistant population of microbes - global warming and changes in weather patterns may increase and distribution of survival of reservoirs and vectors - known diseases may spread to new geographic areas by modern transportation - previously unrecognized infections may appear in individuals living or working in reagin undergoing ecological changes brought by natural disaster, reconstruction, wars, and expanding human settlement - animal control measures may affect the incidence of a disease - failures in public health |
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Epidemiology |
- the science that studies when and where disease occur and how they are transmitted in a population |
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Descriptive Epidemiology |
- entails collecting all data that desribe the occurence of the disease under study - includes information about the affected individuals and the place and period in which the disease occurred - retrospective because the epidemiologist backtracks to the cause and source of the disease |
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Analytical Epidemiology |
- analyzes a particualar disease to determine its probable cause - can be done in two ways: case control method and cohort method |
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Case Control Method |
- epidemiologist looks for factors that might have preceded the disease - these statistics are compared to determine which of all the possible factors: genetic, environmental, nutritional, and so forth might be responsible for the disease |
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Cohort Method |
- the epidemiologist studies two populations: one that has had contact with agent casuing diease and another that has not |
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Experimental Epidemiology |
- beings with a hypothesis about a particular disease; experiments to test the hypothesis are then conducted with a group of people |
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Case Reporting |
- a procedure that requires health care workers to report specified diseases to local, state, and national health officials - provide epidemiologist with valuable leads regarding their origin and spread of a disease |
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Centers for Disease Control and Prevention |
- a branch of US public health service is a central source of epidemiological inforamtion in the US |
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Mortality |
- the number of deaths from a disease - data usually organized by state |
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Notifialbe infectious diseases |
- are diseases for which physicians are required by law to report cases to the US public health service |
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Morbidity Rate |
- the number of people affected by a disease in a given period of time in realtion to the population |
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Mortality Rate |
- is the number of deaths resulting from a disease in a population in a given peirod of time in realtion to the total population |
