helminths Flashcards
what are the 2 parasitic types of helminths that affect humans
flatworms and roundworms
what is an invertebrate
- without a spinal column
- over 30 phyla
- one cluster of hox genes
how do parasites reproduce
- sequential hermaphrodites
- male and female parts join and break off
how do parasitic worms survive
- live and feed off host
- disrupt hosts nutrient absorption causing weakness and disease
what is the name for round worms
phylum Nematoda
what is the name of flukes
trematodes
what is the name for tape worms
cestodes
what are the characteristics of platyhelminths
- flattened - flat worms
- usually leaf shaped
- covered by cytoplasmic tegument
- no body cavity - acoelomate
- no digestive system
- excretion by ciliated cells
what tissue does tremoda - the flukes attach to
- use anterior and ventral suckers
- gillis, lungs, liver and intestines
what are the characteristics of Cestoda tapeworms
- no digestive cavity
- 7 difference species with a primary host as humans
- intermediate hosts are cows, pigs and fish
what is the name of a pork tapeworm
taenia solium
what is the name of a beef tape worm
taenia saginata
what is the name of an asian tapeworm
taenia asiatica
what infection does taenia solium cause
cysticercosis
what are the symptoms of cysticercosis
- tissue infection
- solid lumps 1-2cm under skin
- affect heart muscle and brain
- cause neurological symptoms - neurocysticercosis
what are the characteristics of nematode
- round cross section
- organs and complete digestive system
- moulting stages
- separate sexes
what nematodes affect the human bowel
Trichuris trichiura (whip worm)
Ancylostoma duodenale and Necator americanus
Enterobius vermicularis
Strongyloides stercoralis
Ascaris lumbricoides
what are the symptoms of trichuris trichiura
- many worms cause abdominal pain, tiredness and diarrhoea
- anemia may occur due to blood loss
where are trichuris trichiura found
eggs in soil where people defecate outside and untreated human faeces is used as fertiliser
how do hookworms cause infection
- eggs in faeces hatch and mature as larvae in soil
- larvae penetrate skin of host
- circulate to lungs and bronchi if swallowed
- attach by mouth to small intestinal mucosa and suck blood
where are enterobius vermincularis found
- ileum and cecum
- faecal - oral infection can occur
how are cellophane and pin worm tested
paddle test - microscopy
what is the name for threadworm
strongyloides stercoralis
what are the symptoms of threadworm
- cutaneous
- GI symptoms
- 60% asymptomatic
