Worms
What’s Eating You for Dinner ?http://curezone.com/image_gallery/parasites/all/default.asp?i=1&n=75
FLATWORMSPYLUM: Platyhelminthes
FREE LIVING PARASITIC
Planaria Flukes & Tapeworms
FLATWORMS ARE ACOELOMATES
PLANARIA
NOTPARASITES
GASTROVASCULAR CAVITY(Combination Digestive & circulatory)
• One opening digestivecavity
http://www.lima.ohio-state.edu/biology/biodiv/animal/planarlp.jpg
FLAME CELLS
• Collect excess water and nitrogen waste
• Excreted through pores in skin
Moving cilia looklike little “flames”
REPRODUCTIONSEXUAL-
(hermaphrodites but trade with partner)
ASEXUAL-
can use regeneration to
grow a new organism from parts
PARASITIC WORMSAnimal host where ADULT feeds and
reproduces = PRIMARY HOST
Animal host where LARVAL formlives and feeds = INTERMEDIATE
HOST
HUMAN BLOOD FLUKESchistosoma
Larva hatches from
egg & infects snail(intermediate host)
Eggs leave body in urine or feces
Adult worms mature & reproduce in blood vessels; eggs travel to intestines or bladder
Larvae grow tails and leave snail
Immature worm burrows through skininto blood vessels
PARASITIC FLATWORMSchistosoma
NOT IN USA but infects over 250 million people worldwide
Worms can block blood vessels to organs causing irritation, bleeding, tissue decay
= __________________SCHISTOSOMIASIS
http://www.coc.org/focus/food/pics/rice_paddy.jpg
TAPEWORMS
PARASITIC FLATWORM (lives in HOST animal intestines)
Dog tapeworm
Attaches with SCOLEX
Head with suckers and hooks to help hold on inside host
TAPEWORM
NO DIGESTIVE SYSTEM
-absorbs nutrients through skin
TEGUMENT protects them from host digestive enzymes and immune system
TAPEWORMS
PROGLOTTIDShermaphroditic reproductive structures
(contain both male & female sex organs)
EGGS INSIDE
TAPEWORMS
Can grow up to 30 ft (2000 proglottids)
Add new proglottids behind scolex Mature ones drop off at tail end and
leave body in feces
http://curezone.com/image_gallery/parasites/all/default.asp?i=65&n=75
EX: BEEF TAPEWORM
Adults attachinside intestinesand absorbdigested food
Proglottids arereleased in feces
Proglottids burst releasing eggs with larvae inside on ground
Cows eat grass; larvae travel through blood vessels;make cysts in muscle
Humans eat undercooked meatcontaining cysts
http://net.unl.edu/wonderwise/12parasi/a-para.htm
ROUND WORMSNematoda
ROUND WORMS ARE PSEUDOCOELOMATES
Ascaris TrichinellaHookwormsPinwormsFilarial worms
http://curezone.com/image_gallery/parasites/all/default.asp?i=1&n=75
PARASITIC ROUND WORM Ascaris
Lives in intestines
Feed on passing food
Females can grow up to 1 ft long & produce 200,000 eggs/day
http://www.biosci.ohio-state.edu/~parasite/images.html
Develop into larvae and burrow through wall into blood vessels
Eggs leave body in feces and enter new host incontaminated food/water
Larvae are coughed up & swallowed;Return to intestines, mature, & mate
http://www.extension.iastate.edu/polk/health/carbon/fact3.htmhttp://www.biosci.ohio-state.edu/~parasite/lifecycles/trichinella_lifecycle.html
ASCARIS LIFE CYCLE
http://curezone.com/image_gallery/parasites/all/default.asp?i=0&n=75
Most common worm infection world wide
Mostly in children
Estimated 25% of world’s population is infected with Ascaris
PARASITIC ROUND WORMSTrichinella
Cysts release larvae that burrowinto intestinal wall &mature
Adults release larvae that travel through bloodstreamto muscles
Larvae forms
cysts in muscle
http://jeggeri.pri.ee/Kontuur/Loomad/pig.gif http://www.biosci.ohio-state.edu/~parasite/lifecycles/trichinella_lifecycle.html
Humans infected by eating undercooked meat containing cysts
PARASITIC ROUND WORMS
Trichinella – Larvae leave intestine and travel through
blood vessels to muscle where they make cysts
Muscle pain & stiffnesscan be fatal if cysts form in heart
= _______________________TRICHINOSIS-
TRICHINOSIS
Less than 100 cases/year in USA from PORK
Most from eating wild game
Curing (salting), drying, smoking, or microwaving meat does not consistently kill infective worms.
FILARIAL ROUND WORMS
are transmitted by insects
FILARIAL ROUND WORMS
Elephantiasis
Adult worms live in lymph nodes causing blockage so fluid back ups
http://www2.niaid.nih.gov/NR/rdonlyres/32FF6DCF-75CF-42D0-BCAE-297EFDE27CF1/0/elephantiasis.jpg
ELEPHANTIASISCommon in tropical countries
Adult worms can grow to 4” long
ELEPHANTIASIS
http://www.acm.uiuc.edu/sigbio/project/updated-lymphatic/lymph3.html
Adult worms live and reproduce inlymph vessels
Mosquito picks up larvae from bloodwhen it feeds
Larvae develop into juveniles inside mosquito
Mosquito injects juveniles whichmigrate to lymph nodes and mature
FILARIAL ROUND WORMS
DOG HEARTWORMCarried by mosquitoes
http://curezone.com/image_gallery/parasites/all/default.asp?i=66&n=75
FILARIAL ROUND WORMS Loa loa
http://www.biosci.ohio-state.edu/~parasite/loa.html
Found in AFRICA
Loa Loa worm• Humans are infected with
larvae when bitten by loa fly
• Larvae mature & crawl around under skin (especially near face)
• Adults mate and produce larvae which can be picked up by another fly and transmitted to another person
http://maven.smith.edu/~sawlab/fgn/pnb/loaloa.html
PARASITIC ROUND WORMSGuinea worm
Found in AFRICA
http://curezone.com/image_gallery/parasites/all/default.asp?i=5&n=75
http://curezone.com/image_gallery/parasites/all/default.asp?i=6&n=75
PARASITIC ROUND WORM Guinea worm
Female bodies under skin fill with eggs and break open; larvae form blisters
Blisters pop and larvae are released in water
Larvae eaten by small crustaceans
Humans infected by drinking water
Larvae mature and adult wormsmigrate to skin
http://curezone.com/image_gallery/parasites/all/default.asp?i=5&n=75
http://curezone.com/image_gallery/parasites/all/default.asp?i=6&n=75
PARASITIC ROUND WORMS
Hookworms
Ancylostoma
Live in intestine; feed on BLOOD
http://curezone.com/image_gallery/parasites/all/default.asp?i=1&n=75
http://www.biosci.ohio-state.edu/~parasite/placoconus.html
Eggs leave body in fecesand hatch as larvae in soil
Larvae are coughed up & swallowed;
http://www.extension.iastate.edu/polk/health/carbon/fact3.htmhttp://www.retiredgreyhounds.co.uk/page12.htmhttp://www.barefooters.org/1995-spring/gifs/mtn_pjl_feet.jpg
HOOKWORM LIFE CYCLE
Adult worms live in intestine and feed on blood
Larvae enter body by burrowing through skin on feet & travel to lungs
Return to intestines; mature & mate
Hookworms in Humans• PROBLEMS
caused by migrating larvae
• Cause intense reaction in skin at site
• Infect 40 million people worldwide
Parasitic ROUND WORMSPinworms
• Most common parasitic infection in United States
• 1/5 children are infected
• Worldwide500 million people are infected with pinworms
http://curezone.com/image_gallery/parasites/all/default.asp?i=16&n=75
Grow up to ½ inch long
Parasitic ROUND WORMSPinworms
• Worms live in intestine
• Females crawl out through anus at night and lay 15,000/day eggs on skin
• Intense itching causes host to scratch
• Eggs under fingernails and on hands are spread back to self or to others when objects/food are touched
SEGMENTED WORMSAnnelida
FREE LIVING PARASITIC
Earthworms Leeches
SEGMENTED WORMS ARE EUCOELOMATES
LEECHES
Medical uses