Final Exam Study Deck:) COPY Flashcards
What percent of human pathogens are viruses and prions
15%
What percent of human pathogens are bacteria
40%
What percent of human pathogens are fungi
20%
What percent of human pathogens are Protozoa
5%
What percent of human pathogens are Helminths
20%
What are the important structural componets of fungi
Have cell walls made of chitin (no peptidoglycan or cellulose)
Have a cell membrane made of a phospholipid bilayer with sterols in them (ergosterol)
What are the 2 forms of fungi
Yeasts and molds
Yeasts are unicellular
Molds are multicellular
What are the formations that yeasts are found in
Pseudohyphae (short chains)
How to yeasts reproduce
by budding
What are molds made of
Hyphae- long Strings of cells
Septate hyphae have walls between cells
Aseptate hyphae have no walls between cells
What types of infections (generally) do molds cause in humans
Fungal infections
Which organism was the original source of penicillin
Mold
Dimorphic fungi change between which two forms
Between mold and yeasts- They are molds when convenient (i.e. in soil) and change to yeast in lungs (i.e. to infect someone!)
What is the route of transmission for protozoal infections
Waterborne, foodborn, contact with farm animals, mice, birds and their feces, swimming or bathing in contaminated water
What are protozoa classified as (multi or unicellular, eukaryotes or prokaryotes?)
Unicellular eukaryotes
What stages of life cycle do protozoa usually have
Usually trophozoite and cyst forms
Trophozoite is active, feeding and reproducing. Cysts are tough dormant forms iwth a wall.
How are cysts from protozoa usually shed
In feces during a GI infection of the person
What are the common routes of transmission for Helminth infections
Transmitted through feces in soil, fecal- oral routes (ingest eggs in soil), Eat undercooked pork containing tapeworm or larvae in cysts, or by mosquitoes
What are the common characteristics of helminths
Multicellular eukaryotes with organs
Have 3 forms: Egg, Larvae, Adult worms
What is the life cycle of ascaris lumbricoides? Include transmission, eggs, larvae, and adult worm stages
-Transmission is fecal-oral through eggs in soil that are ingested by waterborne or foodborne routes.
-Eggs hatch into larvae in intestines
-Larvae penetrate host blood vessels and migrate to alveoli of lungs
-Larvae are coughed up and swallowed back into intestines where they grow into adult worms
What are the 6 steps required for a pathogen to infect its host
Exposure
Transmission/Entry
Adhesion
Invasion
Infection
Evasion of the Host immune System
“Every Tiny Ant is in Euphoria”
- I would like to be a tiny ant, they don’t study much, so they’re euphoric.
What is the difference between an active and passive carrier of a pathogen
Active carriers are infected with the disease and can transmit it to others
Passive carriers are NOT “infected” but are asymptomatic and can carry the pathogen on their skin or in their blood to transmit to others.
Active Carriers are always symptomatic- true or false?
False- They can be symptomatic or asymptomatic
Describe contact transmission
There is indirect, direct, droplet, and congenital contact transmission. The infected person or their fluids go directly to the susceptible person (or via a surface, etc)