Nematodes Flashcards
What are the different forms of nematode?
Rhabditiform and Filariform (the rhabditiform are shorter than filariform)
What are the different nematode classes?
Secernentea and Chromadorea and Enoplea
Secernentea= Rhabditia and Spiruria
Rhabditia –> Rhabditoidea and Strongyloides
Enoplea= Dorylaimia and Enoplia
Dorylaimia –> Trichinellia
The parasitic diseases caused by helminth (nematodes and platyhelminths)
What are the subgroups of Trichinellida?
Trichinella spiralis
Capillaria
Trichuris
What are the filariasis diseases transmitted by?
Mosquitos
What are the type of filariasis?
Lymphatic –> Due to Wuchereria bancrofti, Brugia malayi
Subcutaneous –> Due to Loa Loa, Onchocerca volvulus
Serous cavity –> Due to mansonella ozzardi and mansonella perstans
Why is Ivermectin toxic to mammals?
Due to similarity of invertebrates- specific channels to vertebrates GABAA-gated chloride channels that inhibit interneurons of CNS
What is the prevention and control for strongyloides?
- Wear shoes when walking on soil
- Proper sewage disposal and faecal management
What is the pathogenesis for strongyloides?
Penetrate skin –> small intestine where they lay their eggs
Can be severe or life threatening in person on corticosteroids or immunosuppressants as can lead to hyperinfection or dissemination
What is the prevention and control from Rhabditodea?
Same as strongyloidea
What is the prevention and control for Trichinellida?
- wash hands when handling raw meat
- Wash surfaces and meat grinders
- Freeze pork well
What is the pathogenesis for Trichinellida?
This infection is due to eating raw or undercooked meat
A zoonotic infection
Infectious cysts in striated muscle tissue –> L1 larvae released –> Mature to adults in small intesting –> New larvae then released by adults
What is the prevention and control for Guinea worm?
- Safe drinking water
- Vector control i.e, Kill copepods
- Health education
- GWEP= a group trying to eradicate guinea worm
What is the pathogenesis for guinea worm?
Ingestion –> penetrate stomach and intestinal wall –> connective tissue fo abdomen to mate –> escape out of formed blister
NO treatment
What is the prevention and control for Onchocercus volvulus?
DEET
Cover skin to prevent biting from black fly
What can cause river blindness with onchocercus volvulus and what is the treatment?
Effect cornea which effects vision
Treat with Ivermectin
Pros and Cons to C.elegans as a model organism?
Pros
- Cheap and easy to keep in laboratories
- Only have a 2-week life span
- Transparent
- Undergo a particular aging process whcih allows them to be easily physiologically or genetically observed
Cons
- Simple body plan
- Lack many defined organs and tissues; which is evolutionary distinct to humans
- Only 1mm in length which makes studying their biochemistry difficult
Both trematodes and cestodes have a scolex, what does the nematode have instead of this?
Muscular oesophagus
Nematodes have a Pseudocoelum what is this?
A false body cavity that lies between body wall and gut
It contains coelomocyte which provides turgor-hydrostatic pressure for animals as a whole, lubricant between tissues and a medium for instracellular signalling and nutrient transport
