Nematodes (Partly from Lecture) Flashcards
Caenorhabdities elegans
-phylum: Nematoda
- non-parasitic
- helped with medical advances
- used in lab for developmental biology
- entire developmental biology mapped (1,000 cells in the adult body, all cell origins are known)
- first to have its genome sequenced
- can be applied to human embryology & nerve regeneration
- can be addicted to nicotine, model for addiction withdrawals
Dracunculus medinensis
-phylum: nematoda
– common name: guinea worms
- causes dracunculiasis
- oldest parasitic disease known on record
- female adult is 3 feet long
- lives in the body for a year
- goes to a lower limb for reproduction
- causes a narcotizing blister, when the individual places the foot in warm water the blister bursts, reversing out its uterus with the eggs coming out
- not curable by drug
- take a piece of gauze and stick and roll the parasite out
- most damage through infections of removal through their enzyme
- tends to be the symbol for medicine and hinted at within the bible
- mostly a rural problem
- takes 2-10 weeks to get the adult out
- received through drinking contaminated water
- eggs are eaten by the cyclops which the humans drink
- cyclops are destroyed by the stomach acid, letting the worms out into you intestine
- burrow out of your intestines
Ascaris Lumbricoides
-phylum: nematoda
- completely blocks the intestines
- causes Ascariasis
- a billion people have this
- primarily in rural china, russia, and japan
- received through consumption of the eggs which are shed in human feces
- adults live in the intestines while the babies live in the lungs (travels through circulatory system)
- when the babies are ready to be adults, they go through the mouth to go back into the intestines to mature
- survives 100 yrs as eggs in the dirt
- has no anchors, size prevents them from being washed away
Necator americanus
-phylum: nematoda
- hookworms
- a billion affected worldwide
- small
- prevalent in america, especially in the rural south
- if children gets them, they cause severe brain developmental problems
- they do have hooks, attach to the intestine and drink blood
- drink too much blood which causes blood lose/anemia
- same as ascaris lumbricodies but they are burrowed into the foot
- received through walking barefoot in contaminated feet
- appear in the mud as “waving”
Trichinella spiralis
-phylum: nematoda
- causes trichinosis
- 10% mortality rate
- smallest one that infects humans
- burrows itself into individual muscle cell
- changes the gene of the muscle to turn into a nursing cell where it basically incubates
- intracellular parasite
- received through undercooked pork
- adults live in intestines
- larvae
Enterobius Vermicularis
-phylum: nematoda
- pinworms
- prevalence of 30% in americans, more common than lice
- usually infected as a child
- very small
- live in the large intestine
- females can tell when the individual is asleep or sleep
- when you are sleeping, the female crawls out and lays eggs around the anus which they attach with glue that causes an itch
- the itch sensation causes one to scratch, essentially causing the spread
- detected through the scotch tape method
Wuchereia Bancrofti
- elephantisais
- filarial worms
- larvae: microfilariae
- transmitted through mosquitoes
- goes to the blood to aggravate the lymph nodes
- forms clusters which appear as edemas - 17 million people worldwide
Onchocera volvulus
- causes river blindness
- central africa
- transmitted through black flies bites
- adults live under the skin
- larvae migrate only at night
- when they die, they release wolbachia
- detected through the immune system by creating a scar tissue (mostly near the eyes)
Dirofilaria immitis
- canine heart worms
- transmitted through bite of mosquitoes
- causes canine heart worms , that clog up the heart valves
- could kill the dog
