Chapter 7 - Infection and Disease Flashcards
disease
any condition that impairs the normal activity of an organism
infectious and non-infectious
non-infectious diseases describe and examples
not caused by a pathogen
cannot be transmitted directly
inherited disorder, nutritional deficiency, autoimmune diseases
inherited (genetic) disorder
carried in the DNA
inherited from parents
e.g. down syndrome, cystic fibrosis
nutritional deficiency
results from lack of vitamins / minerals in the diet
e.g. osteoporosis, anemia
autoimmune diseases
results from the immune system failing to properly detect its own cells (self) from those of other organisms (non-self)
e.g. multiple sclerosis, rheumatoid arthritis
infectious diseases
caused by a pathogen
can be passed on / transmitted
e.g. influenza, chicken pox, diphtheria
pathogen
organism able to cause disease in a host
transmission of pathogens
body contact sexual contact droplet or airborne contamination of food / water carrying or injecting vector
carrier
a person infected with a pathogen with who shows no symptoms
non-cellular agents
infective agents that lack cellular structure
prions, viruses
prions
made of protein PrP
two types: PrPc, PrPsc
PrPc
prion; normal protein found naturally in th body
PrPsc
prion; disease causing infectious form
resistant to proteases
viruses
non-cellular
infectious agents
host specific
e.g. cold, influenza, AIDS, rubella
bacteriophage
viruses that infect bacteria
cell lysis
destroys the host cell
retroviruses
contain RNA instead of DNA
e.g. HIV
Antiretroviral therapy
treatment of viral infections
more difficult than bacteria
can damage host cell
interferon
protein secreted by host cells infected with the virus
inhibits the destruction of other cells
blocks viral protein synthesis
cellular agents
cellular organisms
bacteria, protists, fungi, parasites
bacteria
unicellular, found everywhere
can tolerate extreme conditions
classification of bacteria
shape
structure
reaction to particular stains: gram stain
structures on bacteria
flagella
capsule: outside cell wall
spores
how bacteria causes disease
reproduce in host
Harms host tissue
produce toxins
binary fission
reproduction in unicellular organisms where one cell splits into two
treatment of bacterial diseases
antibiotics
protists
heterotrophs tha absorb nutrients from their host and can reproduce both sexual and asexually
treatment of protists
no effective vaccines available
fungi
heterotrophs that obtain nutrients from the decomposition of dead organic matter
superficial: skin, hair and nails
e. g. ringworm, tinea
treatment of fungi
anti fungal ointments and oral preparations
parasites
an organism which obtains food from another organism to the detriment of its host
cause diseases but usually don’t kill: lose home
endoparasites
live inside the body of the host organism
e.f. tapeworm, heartworm
ectoparasites
live outside / on the body of the host organism
e.g. head lice, fleas
host
organism or cell that a specific parasite live in or on
intermediate host
a secondary host
parasite reproduction strategies
hermaphrodites
produce large numbers of eggs
reproduce sexually and asexually
proteases
enzymes that break down proteins
