Custom Quiz # 1 Flashcards
One of the main mechanisms that is used by mucus to prevent infection is?
traps organisms
The urinary tract mainly resists bacterial infection by
the continual flushing action of urine
Pattern recognition receptors contribute to non-specific body defense systems by
recognising components of microorganisms as foreign
polymorphs are white cells that consist of the following 3 types of cells?
neutrophils, basophils and eosinophils
basic cellular component of pus?
neutrophils
non-specific (innate) immune defense contains the following 5 elements?
complement, mast cells, opsoninisation, interferons and cytokines
protective effect of resident commensal microorganisms is called?
colonisation resistance
after having an initial infection, resistance to reinfection is known as?
acquired immunity
acquired immunity is characterised by?
being highly specific, long-lasting and dependent on lymphocytes
five major signs of inflammation?
redness, swelling, heat, pain and loss of function
vasodilation and increased capillary permeability are caused by?
histamine
primary cell type involved in initiating the inflammatory response is?
tissue mast cell
group of proteins found in blood serum which act with antibodies to destroy foreign cells or bacteria
complement
the allergic inflammatory response begins when
IgE antibodies are produced after exposure to an allergen and then bind to mast cells
viruses are classified according to their genetic composition which are?
RNA based and DNA based organisms
four main types of microbes
viruses, bacteria, protozoa, fungi
yeast that causes thrush
candida albicans
most effective way to manage eucaryotic parasites that are common in a community is to?
understand the life cycle and then interrupt its growth and reproduction at vulnerable moments in the life cycle
examples of specific body defense systems against infection and foreign substances (list 7)
cytotoxic t cells
IgG
Antibodies
B lymphocytes
T lymphocytes
CD4 cells
Antigen Presenting Cells
which body defense mechanisms prevents the entry of pathogens into the body or to destroy them quickly if they enter.
non-specific (innate) immunity
example of a chemical mediator of inflammation?
quiz answers: histamine, prostaglandin, kinin and complement
vasoactive mediators - histamine, bradykinin, leukotrienes, prostaglandins C3a and C5a platelet activating factors
chemotactic factors - leukotrienes, c5a certain interleukins tumour necrosis factor, microbial components platelet-activating factor
main phagocytic cells in the body are
macrophages and neutrophils
role of opsonins
enhance phagocytosis
enhancement of antigen adherence to phagocytic cells
complement
the activity of a ___, in which histamine is release from mast cells
complement
the activity of a ___, in which causes lysis of foreign cell membranes
complement
activation of inflammation by chemotaxis of phagocytes?
complement
the body’s defences against any kind of pathogen
non specific resistance
what is an infectious agent?
particular organism that grows at a site which is not normally found, causing an infection
what is a pathogen?
organism that causes infection or disease
what is an epidemic?
break out of infection or disease in a localised area
what is a commensal microflora?
resident micro-flora at various site in the body that is beneficial and prevents new organisms (pathogens) gaining foothhold
what is a vaccine?
a suspension of killed or attenuated (weakened) organisms administered for prevention and treatment of infectious disease
what is an antibiotic?
substance produced by a certain bacteria and fungi that prevents the growth of or destroys other bacteria
what is an infection?
invasive and multiplication of microorganisms in body tissues especially that cause local cellular injury
what is a prion?
one of several kinds of infectious proteins that cause transmissible neurodegenerative diseases
what is innate (non-specific) immunity?
immunity that has been present since birth
what is cytokine?
inflammatory cells and inflamed tissues which release a range of hormone such as proteins.
what is acquired (specific) immunity?
develops post infection providing immunity from re-infection from the same organisms
what is a leucocyte?
white blood cell
what is the definition of virulence?
degree of pathogenicity of an organisms and how quickly a disease can spread
what is interferon?
a protein that protects uninfected host cells from infection
what is an antibody?
a protein in the blood and bodily fluids secreted by plasma cells in response to a bacterial antigen.
define phagocytosis
engulfing and destruction of micro-organisms and foreign by phagocytosis in the blood
define complement
a substance present in normal serum which combines with an antigen-antibody complex to destroy bacteria
define pyogenic infection
infections where pus is formed usually caused by bacteria
basic component of pus?
neutrophils
lysozyme is more predominantly found in
neutrophil
natural killer cells are part of what type of immunity?
innate immunity
main function of inflammatory response
prevents the spread of an infection
redness and heat seen in an inflamed area are partly the results of?
increased blood flow to the area
what is released during the inflammatory response?
chemical mediators (vasoactive and chemotactic)
what are the key signs of inflammation?
swelling
redness
pain
heat
in systematic inflammation, pyrogens function to?
stimulate fever production
function of MHC class I molecules
allow the immune system to respond to antigens inside the cells
when a MHC class I antigen complex displays a foreign antigen on the cell surface, it prompts the immune system to?
destroy the displaying cell
often the first antibody produced in response to an antigen is?
IgM
may initiate inflammation and enhance phagocytosis
antibodies
antigens are more susceptible to phagocytosis as a result of?
opsonisation
function of neutrophil
first cell to enter infected tissue
function of monocyte
will become macrophage in tissue
function of natural killer cell
lyses tumor and virus-infected cells
function of eosinophil
cell that increases in number during a parasitic infection
function of mast cell
nonmotile cells in connective tissue that promote inflammation
where are b cells produced?
bone marrow
define host when discussing infectious disease
an organism in which another organism is nourished and harboured
define pathogen when discussing infectious disease
an organism capable of causing disease in another organism
define bacterial colonisation
the persistent presence and multiplication of bacteria without tissue invasion or damage
define bacterial exotoxins
bacterial proteins that are secreted by cells during growth
define endotoxins
toxins within the walls of bacteria that is released when cells die
bacteria can evade or evoke a less effective immune response from the host by ANTIGENIC VARIATION in which they?
alter their proteins or lipopolysaccharide carbohydrates on their surface
bacteria can evade or evoke a less effective immune response from the host by MOLECULAR MIMICRY in which they?
express molecules on their surface that enable them to mimic host cells
mycobacterium tuberculosis evades the host defences by?
invasion of host cells
pathogenesis of bordetella pertussis, which causes whooping cough, involves?
colonisation of ciliated cells
secretion of an exotoxin
proliferation of bacteria
difficulty clearing mucous
most recent vaccination against pertussis uses
a toxoided toxin and adhesion proteins from the bacteria
examples of antimicrobial
antibacterial
antiviral
antifungal
antihelminthic
define minimum inhibitory concentration
the lowest concentration that will inhibit growth of the organism
when we describe the spectrum of an antibiotic, we are describing how
bacteria have a susceptible component of their cellular structure and humans have a less susceptible target of action
penicillin belongs to which type of antibiotic?
beta-lactams (β-lactam)
penicillin acts to kill cells by
inhibiting the building of cell walls
aminoglycoside antibiotics act to kill cells by
affecting protein synthesis at the ribosome to generate nonsense proteins which reduces cell wall integrity
what are the common side effects of antibiotic use?
vomiting
diarrhoea
rash
thrush
what mechanism does antibiotic resistance occur which can be caused by overuse of antibiotics in the community?
the bacteria produce enzymes that destroy the antibiotic and reduce the targets in their cells
give 4 examples of a mechanism for the spread of antibiotic resistance between bacteria
- person-to-person transfer of resistant bacteria
- conjugated genetic transfer of genetic material between bacteria
- transformation of bacterial genetic material
- transfer of genetic material between bacteria by bacteriophages
define subclinical viral infection
infection with a virus that produces an immune response but produces no discernable symptoms
in order for a virus to produce an infection in a susceptible host,
sufficient viable virus must reach the host and overcome initial barriers to infection
define endemic disease
the continual or habitual presence of disease
define epidemic disease
occurs at a rate in excess of normal expectancy
define pandemic disease
occurs all over a very large geographic area or the whole world
define arbovirus
spreads by insects, ticks and mites, that are blood feeding
human papilloma viruses (causes warts) are spread by?
minor trauma of the skin with direct contact
successful method used to reduce the spread of arboviruses
eradication of mosquitoes and their breeding sites
which route of viral transmission results is the fastest spread of disease?
inhalation of aerosol
for which of the following reasons are aerosol-spread respiratory viral infections more common in winter
the colder weather allows the virus to remain active for longer
what 4 methods effectively reduce the spread of respiratory viruses
isolation of infected individuals, facemasks, proper disposal of tissues and hand washing
transmission of gastrointestinal viruses occurs more easily than for other viruses because they
survive longer outside the body
2 main types of gastrointestinal virus transmission are
from contaminated food or water and person to person faecal oral spread
sexual transmission of viruses is very efficient because
the virus is kept moist and does not have to survive long on route between people
vertical transmission of virus is the spread of the virus from:
mother to neonate
rubella and cytomegalovirus are examples of diseases that can be spread via?
the placenta to the unborn child
for a virus, a reservoir is a place where
the virus can persist and be released to cause an outbreak of disease
recent viral infection can be demonstrated by examining the serum of people and finding what antibody?
IgM antibodies against the disease
give 4 factors that impact the epidemiology of virus infections
rapid air travel
sexual activity
weather
overcrowding
4 general measures that are used to control viral disease are?
interrupt the spread of the virus
vaccinate against the virus
give antiviral medication
4 general measures that are used to control viral disease are?
interrupt the spread of the virus
vaccinate against the virus
give antiviral medication
manage the person’s disease
antibiotics are ineffective against?
viruses
mode of action of antiviral medication
suppress infection and reduce symptoms of chronic viral disease
passive immunisation against viral infections is achieved by giving patients
immunoglobulin from the plasma of individuals who are immune to the virus
the problem with PASSIVE immunisation is that
the protection diminishes quickly over 2 to 4 months
the advantages of having live virus vaccines are that they do not?
do not have to be injected
are cheap and usually require only a single dose
example of live virus vaccine
measles
example of a non-replicating virus vaccine?
influenza
it continues to be difficult to produce a vaccine against HIV because?
- no one has a natural immunity
- no animals that are similarly infected
- virus is diverse
type of vaccination which reduces 60-90% but does not provide complete protection
influenza vaccination
state 4 purposes of vaccination
- ensuring that the cost of the vaccination produces a worthwhile benefit
- preventing infection in at-risk people
- considering the most appropriate age to vaccinate
- preventing a disease epidemic
NOTE: IT DOES NOT CURE VIRAL INFECTION
main problem with influenza vaccination is that?
it has to be recreated each year for new influenza strains
does the broad-spectrum antibiotic REDUCE or INCREASE the body’s non-specific defences?
reduce
what can cause secondary immunodeficiency?
process of ageing
after having an initial infection, resistance to reinfections is known as?
acquired immunity
define antigen
a foreign substance that activates the immune system
asymptomatic carriers are infected hosts who contribute to?
the spread of infection
define asymptomatic carrier
person or other organism that has become infected with a pathogen, but shows no signs or symptoms
virulence is a measure of a pathogen’s ability to cause?
disease or infection and is measured using the terms infectious dose (ID 50) and lethal dose (LD50)
virulence is determined by what factors?
- host mucosal adherence
- resistance to defences
- production of toxins and enzymes
14 systems that are non-specific in their defence against infection and foreign substances
- skin
- lysozymes
- stomach acid
- lactoferrin
- mucociliary escalator
- phagocytes
- natural killer cells
- acute inflammatory response
- antimicrobial proteins
- complement
- cytokines
- normal bacterial flora
- digestive enzymes
- mucous membranes
