Dealing with disease 9 Flashcards
Pathogen
cellular and non cellular agents that cause disease
which include bacteria, viruses,
fungi, protozoa, prions, and worms
Disease
- Conditions where part or all of an organisms normal bodily functions are upset or fail to function
properly - can be infectious, contagious and/or
genetic
Infectious Disease
-Condition that impairs normal function of an organism
- caused by the invasion
/ growth of a pathogen within an organism and can be passed from one host to another
Endemic: (low level)
a disease restricted to a region or part of a region and is present in a
relatively low level of the population
Epidemic: (mid-level)
- A disease that affects a large number of individuals at the same time
- Disease usually travels quickly and is easily transmitted
Pandemic: (global)
-A disease that is worldwide distributed and affects everyone.
- This disease is easily
transmitted
Control infectious disease:
- Behavioural Control (Ex: Condoms/thongs/sunscreen)
- Modifying the environment (Draining swampy ground / spraying disinfectants)
- Treatment (Antibiotics/Antivirals)
- Immunisation
Transmission of disease:
Vector Transmission – bites from variety of animals can introduce pathogens (mosquitos / dogs)
Vehicle Transmission – transmission via medium such as blood, water, food or air
Other disease types
society – drug abuse, alcohol, heart disease | environment – safe drinking water,
sanitation, food | genetics – familial, spontaneous
Antigen
-a substance that is recognized by the immune system as either foreign or self. -foreign antigen -->trigger an immune response
There are two types of antigens: Self and non self, what is non self?
molecule from
outside the body that is recognised
by the immune system and
initiates an immune response
Major histocompatibility complex
(MHC) proteins
- a group of proteins present on the surface of cells that enable the immune system to distinguish between self/non-self material.
Autoimmune disease
a condition where the immune system no
longer recognizes self-antigens as self and B and T cells attack cells
as they are seen as foreign/non-self
Allergen
a non-pathogenic antigen
that triggers an allergic reaction
Allergic reaction
an inappropriate
immune response to a
non-pathogenic antigen
What are the two MHC classes and where are they present:
Class I MHC Antigens – on surface of all body cells (except
RBC), cells invaded by virus have Class 1 MHC Markers altered by
the viral proteins and thus recognised as non-self
Class II MHC Antigens – are restricted by antigen presenting
what are the features/Nature of Disease and describe them,
Virulence – intensity of the pathogenic effect, degree pathogen inflict damage on host
Resistance – individual’s level of susceptibility to pathogen
Incubation Period – the time between infection and symptom development, depends on pathogen achieving
sufficient number, reaching target tissue and toxin accumulation
Cellular pathogens
a pathogen that has a cellular structure and exhibits the processes of a living organism. Examples include bacteria, fungi, protozoa, and parasites such as worms
Non-cellular pathogens
a pathogen that has a cellular structure and exhibits the processes of a living organism. Examples include bacteria, fungi, protozoa, and parasites such as worms
Bacteria
- Unicellular prokaryotes that can infect almost any part of the body
- cellular
- meningitis, tetanus
Fungi
-Eukaryotic organisms like yeasts and moulds and contain long, branching filaments called hyphae. -cellular - They can cause a variety of diseases in humans including thrush, athlete’s foot.
Worms
-Multicellular invertebrate parasites whose development include egg, larval, and adult stages -cellular - Parasite (e.g. tapeworm) infection leading to malnutrition
Protozoa
-Single-celled eukaryotes that can be free-living or parasitic. -cellular -Plasmodium causing malaria
Viruses
-An infectious agent composed of genetic material (DNA or RNA) inside a protein coat (capsid) and surrounded by a lipid envelope. Viruses are not able to independently reproduce, instead they insert their genetic material into a host’s cell and using the cell to replicate. - Non cellular - Rhinovirus causing the common cold -Influenza causing the flu -Ebola virus causing ebola