Unit 2 topic 1 Infectious disease Flashcards
What is healthy?
An individual that can function physically, mentally and socially well.
What is a disease?
Any physiological abnormality or significant disruption in the ‘normal’ health of an organism.
What is an abiotic factor (disease)?
nutrient deficiency, drought, lack of oxygen, excessive temperature and pollution
What is a biotic factor (disease)?
Factors within the organism or caused by an organism.
What is it mean to be infectious?
Caused by another organism or organic agent and can be passed from one individual to another.
What is it mean to be non-infectious?
Cannot be spread from one individual to another
What are some causes of non-infectious diseases?
. Inherited conditions
. Environmental conditions
. Nutritional diseases.
What are the causes of infectious diseases?
. Caused by pathogens (classes as parasites)
Ectoparasite
live outside their host e.g. Fleas
Endoparasite
live inside their host e.g. Tape worm
What is a Primary host?
Where parasites can reach maturity and reproduce
What is a secondary host?
temporary host
What is a Reservoir host?
Can harbour a parasite and have no ill effect (may or may not pass on pathogen)
What is a vector?
Uses another organism to move from one organism to another.
What is a Carrier?
Infected with a pathogen but doesn’t exhibit symptoms
What is an Endemic?
Where a disease exists in low levels within a community
What is contagious?
Infectious disease can pass directly between two individuals of the same species
What is Pandemic?
The disease spreads to other countries
What is an Epidemic?
Larger than normal numbers of individuals is infected
What is Pathogen virulence?
The pathogen’s ability to cause disease, which is measured through:
. How many individuals does the microorganism infects
. How quickly it spreads through the body
. How many hosts die
What are the different Virulent factors?
- Adhesion
- Colonisation factors
- Invasion factors
- Toxins
- Immune response blockers
What is the function of Adhesion?
Sticking to a molecule on the membrane of the host cell
What is a colonisation factor?
Proteins allow the pathogen to colonise the host’s body.
What is an invasion factor?
Proteins that allow pathogens to enter the host cells
What are toxins?
Proteins that poison host cells and cause tissue damage. The damage causes nutrients for pathogen survival
What are immune response blockers?
bacteria and fungi have a capsule that blocks the host’s immune system
What is a Protozoan?
Unicellular animals
What are tapeworms?
infection of the digestive tract by adult parasitic flatworms
What are Arthropods?
Small animals such as the mite, head lice, crab louse
What is bacteria?
Prokaryotic cells, which they are found everywhere. Some cause disease and some are critical for life on earth.
What are the Bacterial structure?
. Cell wall
. Cell membrane
. Capsule
. Flagella
What is a Heterotrophic bacteria?
Must get their food from a source of preformed organic matter:
What is a parasite?
live on or in the organism and can cause disease.
What is a Saprobes?
feed on the remains of dead plants and animals.
What is an Autotrophic bacteria?
can make their own food:
What are the factors bacterias are limited to growth?
Temperature pH moisture content nutrient availability competition from other organisms
How do bacteria make you sick?
.They get the food they need to survive and reproduce.
. Destruction of the host’s cells by bacterial enzymes
What are vectors?
Are carriers of the pathogens but show no symptoms of disease
What is an Antigen?
Substances that can evoke an immune response.
What are the first line of defence?
. Skin
. Ciliated epithelium
. Secretion that deters the microbes
What are the second line of defence?
. Defensive molecules
. Cytokines
. Fever
What are defence molecules cytokines?
Coordinate aspects of immune response which are released by body cells in response to cell damage or presence of a pathogen.
What are phagocytosis?
Process by which a cell uses its plasma membrane to engulf a large particle, giving rise to an internal compartment called the phagosome. I
What is the Lymphatic system?
Collection of organs involved in the production, maturation, and harbouring of whiteblood cells called lymphocytes.
What is the two mechanism of immunity
. Cell-mediated immune response
. Humoral immune response
Third line of defence involves two broad type of lymphocyte which are?
B-lymphocytes (Bone Marrow)
T-lymphocytes (Thymus)
What is the characteristic of primary immune response
. Memory cells (B, Th, Tc) are made from this process.
. 10 to 17 days from exposure to peak antibody and cytotoxic T cell production.
. Person starts to recover from illness symptoms
What is the characteristic of secondary immune response
. Faster and increased immune response to same antigen if exposed again.
. Immunological memory increased rate of proliferation and differentiation in second exposure.
. Symptoms don’t usually appear.
What is passive immunity?
. The short-term immunity which results from the introduction of antibodies from another person or animal.
What is active immunity?
The immunity which results from the production of antibodies by the immune system in response to the presence of an antigen.
What are the two different mechanism of transmission?
. Direct contact transmission
. Indirect contact transmission
How does regional spread of disease work?
. Road networks
. Airports
. Infrastructure system (e.g. water supply)
. Social networks (e.g. large gathering)
What is the SIR model?
Basic model used to analyse spread of disease. Uses an advanced mathematical formula.
What is R nought?
Measure (estimation) of how many people will contract a disease from the person who is the primary source.
What are some ways to decrease disease transmission?
. Medicine
. immunisation
. Personal hygiene
What is community immunity?
Critical portion of community protected against a
disease. Also known as Herd Immunity.
Who benefits from herd immunity?
. Young children
. Elderly people
. Pregnant women
. Individuals who are already ill.
