Lab Exam 2 Flashcards
(22 cards)
What are helminths and what are some types of helminths?
worms - multicellular eukaryotic animals
- possess digestive, circulatory, nervous, excretory and reproductive systems
- some have complex lifestyles with larval/adult stages
Ex. flatworms (flukes and tapeworms) and roundworms
How to helminths reproduce?
dioecious: male and female reproductive organs in different animals
monoecious (hemaphroditic): one animal has both make and female reproductive systems
- ex. Cestodes (tapeworms)
describe how Necator americanus affects humans?
hookworm (type of roundworm/nematode)
- larva enter the human through bare feet on warm, moist soil
- larva penetrate respiratory membrane and travel up and tut of lungs through ciliary action
- larvae get coughed up and swallowed - enter the GI tract
- mature into adults in small intestine and produces ova - attaches and feeds to host blood and tissue
- hookworm ova from feces hatch in soil to repeat
describe how Enterobius vermicularis (pinworm) affects humans?
pinworm - type of roundworm (nematode)
1. eggs reside on perianal folds - larvae mature within 4-6 hours
2. eggs ingested by humans
3. larvae hatch in small intestine
4. adults reside in lumen of cecum - female migrates to perianal region at night to lay eggs
common in babies - itchy diapers and touching toys can spread pinworm
describe how Taenia solium (pork tapeworm) affects humans?
tapeworm = cestode
- Pig eats feces of infected human that contained embryonated eggs
- Cysticercus developed on the flesh of the pig
- inadequately prepared pork containing cysticercus gets injected by human - if humans ingest eggs, they can develop and be found in any tissue
- cysticercus mature into tapeworm in small intestine
- ova and ova filled proglottids passed into hum an feces - can either travel through fecal oral route or travel through pig
Describe how Trichinella spiralis (round worm) affects humans?
- Pig meat infested with juveniles is not cooked properly - ingested by humans
- Larvae deposited by adult worms into blood or lymph vessels
- Larvae lodge into muscle cells and encyst, forming nurse cells
many different symptoms due to migration throughout the body
Describe how Schistosoma mansoni affect humans?
thematode/flatworm
- eggs hatch and release miracidia
- miracidia penetrate snail tissue and become sporocysts in the snail
- cercariae are released by the snail into the water - can freely swim
- penetrate the skin of humans
- becomes schistosimulae - goes into body circulation
- goes to liver to mature not adults - migrate to mesenteric venules of bowel/rectum
how do protozoa reproduce?
fission: asexual reproduction in which one protozoan cell splits into 2
schizogony: asexual reproduction in which multiple protozoan nuclei form in host cell before individual protozoan cells form
what are the two stages of protozoa?
trophozoite: motile, feeding, reproducing form
cyst: nonmotile, protective form to survive harsh environments
- excreted out of host
what is amebiasis? what protozoan causes it?
Entamoeba histolytica
- dysentery and liver damage if it migrates to liver
transmitted through fecal contaminated water/food
trophozoite exists in host and fresh feces
cyst services in water, soils, and foods
amoeboid - moved by extending lobelike projections - pseudopodia
what is Giardiasis? what protozoan causes it?
Giardia lamblia - most common protozoan, most common cause of GI protozoan parasitic disease in US
Beaver’s revenge - chronic diarrhea - typically not bloody
fecal contaminated water
has trophozoite and cyst forms, moves using flagella
What is African Sleeping Sickness and what protozoan causes it?
Trypanosoma brucei
invades bloodstream: fever and weakness
invades CNS: extreme sleeping sickness and coma
transmission: tsetse fly - insect vector
- introduced to humans through insect bite
complex life cycle:
insect: salivary gland and midgut
human: bloodstream, evades immune system by antigenic variation - changes in surface antigens so that there cannot be an appropriate immune response
What is Chagas’ disease and what parasitic protozoan causes it?
Trypanosoma cruzi
insect vector: Triatoma bugs (Kissing bugs)
- found in Mexico, Central/south america
3 stages:
initial - swelling at bite site, fever, swollen lymph nodes, myocarditis
chronic - asymptomatic - penetrates macrophages and heart cells
final - congestive heart failure - pseudocysts form clusters of parasite in heart muscle tissue - unable to pump blood away
What is malaria and what parasitic protozoan causes it?
Plasmodium - leading parasitic infection, major killer
insect vector: Anopheles mosquitos
symptoms: fever, chills, infects red blood cells and causes them to lyse
life cycle complex (insect-human)
- invasion of liver cells followed by invasion of RBC
- carried between hosts through mosquitos
evades host defense - multiplies in RBC by schizogony
what are molds?
multinucleate, filamentous fungi
describe the following anatomy of molds: hyphae, septa and mycelium. what are the types of mycelium?
hyphae: branching, tubular structure typically divided into cell like units called septa
Septa: individual fungal filaments
mycelium: total mss of hyphae
- vegetative mycelium: anchors mold and absorb nutrients
- aerial mycelium: produces asexual reproductive spores
how do mold reproduce asexually?
sporangium: saclike structure containing sporangiospores
conidia: fungal spores specialized on the ends of aerial hyphae (conidiophores)
describe the fungi penicillium
common household mold, frequent food contaminant
produces conidia in chains on finger like projections call sterigmata
source of PCN antibiotic
describe the mols aspergillus
common food contaminant
some produce mycotoxins (aflatoxin)
opportunistic pathogen in respiratory tract of compromised host - causes aspergiollosis - necrotizing pneumonia
produces conidia
describe the mold rhizopus
opportunistic pathogen in wounds and respiratory infection in compromised hosts
anchoring structures called rhizoids are produces on vegetative hyphae
asexual and sexual reproduction:
- asexual: form sporangiospores on sporangium (looks like wand)
- sexual: hyphal types +/- join to form a sexual spore called zygospore (looks like bow)
what is the kirby bauer test? what does it measure?
disk diffusion method test that tests the efficacy of an antimicrobial chemical on a specific microbe
antimicrobial paper disks are placed on inoculated plate
zone of inhibition: clearing around antimicrobial disk, measured across diameter, used to determine susceptibility of organism to antibiotic
MIC - minimum inhibitory concentration: [drug] at which microbe no longer grows
what is the ELISA test?
enzyme linked immunosorbent assay - used to detect antigen or antibody within a sample
- antigen-antibody reaction: if target antibody is present, antibody specific to original antibody binds. if this binding is present, it causes enzyme to change color
steps of ELISA test
- add solution of interest (or -/+ control). wait 5 minutes. tap off solution
- add washing solution. tap out of wells. repeat 3x
- add drops of antibody solution to cells. wait 5 minutes and tap off
- add washing solution gain
- add color reagent solution to each well
