Worms What’s Eating You for Dinner ?

FLATWORMS PHYLUM: Platyhelminthes FREE LIVING PARASITIC Planaria Flukes & Tapeworms FLATWORMS ARE ACOELOMATES

PARASITIC WORMS Animal host where ADULT feeds and reproduces = PRIMARY HOST Animal host where LARVAL form lives and feeds = INTERMEDIATE HOST

HUMAN BLOOD FLUKE Schistosoma Adult worms mature & reproduce in blood vessels (PRIMARY HOST) ; eggs travel to intestines or bladder Immature worm burrows through skin into blood vessels Larvae grow tails and leave snail Eggs leave body in urine or feces Larva hatches from egg & infects snail (intermediate host)

PARASITIC FLATWORM Schistosoma Eggs 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 PARASITIC FLATWORM (lives in HOST animal intestines)

TAPEWORM Attaches by scolex and absorbs nutrients through skin Tegument protects them from host digestive enzymes and immune system

COVERING for PROTECTION CUTICLE- NON-CELLULAR coating made by cells TEGUMENT- CELLS fused together like armor

Tapeworm SCOLEX Head with suckers and hooks to help hold on inside host

PROGLOTTIDS hermaphroditic reproductive structures TAPEWORMS PROGLOTTIDS hermaphroditic reproductive structures (contain both male & female sex organs) EGGS INSIDE

TAPEWORMS Can grow 30-50 ft (2000 proglottids) Add new proglottids behind scolex Mature ones drop off at tail end and leave body in feces

BEEF TAPEWORM Intermediate host Primary host Adults attach inside intestines and absorb digested food Humans eat undercooked meat containing cysts Intermediate host Primary host Proglottids burst releasing eggs with larvae inside on ground Proglottids are released in feces Cows eat grass; larvae travel through blood vessels; make cysts in muscle http://net.unl.edu/wonderwise/12parasi/a-para.htm

ROUND WORMS PHYLUM: Nematoda Some FREE LIVING PARASITIC Ascaris Trichinella Hookworms Pinworms Filarial worms ROUND WORMS ARE PSEUDOCOELOMATES

Ascaris PARASITIC ROUND WORM Lives in intestines of humans, pigs, horses 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

ASCARIS LIFE CYCLE Larvae are coughed up & swallowed; Return to intestines; mature & mate Eggs leave body in feces and enter new host in contaminated food/water    Develop into larvae and burrow through wall into blood vessels http://www.extension.iastate.edu/polk/health/carbon/fact3.htm http://www.biosci.ohio-state.edu/~parasite/lifecycles/trichinella_lifecycle.html

PARASITIC ROUND WORMS Trichinella Intermediate host Cysts release larvae that burrow into intestinal wall & mature Humans infected by eating undercooked meat containing cysts   Primary host Larvae forms cysts in muscle Adults release larvae that travel through bloodstream to muscles  http://jeggeri.pri.ee/Kontuur/Loomad/pig.gif http://www.biosci.ohio-state.edu/~parasite/lifecycles/trichinella_lifecycle.html

PARASITIC ROUND WORMS Trichinella – TRICHINOSIS- Larvae leave intestine and travel through blood vessels to muscle where they make cysts Muscle pain & stiffness Can be fatal if cysts form in heart = _______________________ TRICHINOSIS-

PARASITIC ROUND WORMS FILARIAL WORMS larvae are carried by insects EX: DOG HEARTWORM Carried by mosquitoes

FILARIAL ROUND WORMS Elephantiasis Adult worms live in lymph nodes causing blockage so fluid back ups

ELEPHANTIASIS Common in tropical countries Adult worms can grow to 4” long

ELEPHANTIASIS

  Mosquito picks up larvae from blood when it feeds Larvae develop into juveniles inside mosquito Mosquito injects juveniles which migrate to lymph nodes and mature Adult worms live and reproduce in lymph vessels   http://www.acm.uiuc.edu/sigbio/project/updated-lymphatic/lymph3.html

FILARIAL ROUND WORMS Guinea worm

PARASITIC ROUND WORM Guinea worm  Blisters pop and larvae are released in water  Female bodies under skin fill with eggs and break open; larvae form blisters Larvae eaten by small crustaceans Humans infected by drinking water   Larvae mature and adult worms migrate to skin

FILARIAL ROUND WORMS Loa loa

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

PARASITIC ROUND WORMS Hookworms Ancylostoma

     HOOKWORM LIFE CYCLE Return to intestines; mature & mate Larvae are coughed up & swallowed;    Adult worms live in intestine and feed on blood Larvae enter body by burrowing through skin on feet & travel to lungs   Eggs leave body in feces and hatch as larvae in soil http://www.extension.iastate.edu/polk/health/carbon/fact3.htm http://www.retiredgreyhounds.co.uk/page12.htm http://www.barefooters.org/1995-spring/gifs/mtn_pjl_feet.jpg

Hookworms in Humans PROBLEMS caused by migrating larvae Cause intense reaction in skin at site Infect 40 million people worldwide

PARASITIC ROUND WORMS Pinworms Most common parasitic infection in United States 1/5 children are infected

PARASITIC ROUND WORMS Pinworms Worms live in intestine Females crawl out through anus at night and lay 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 WORMS PHYLUM: Annelida FREE LIVING PARASITIC Earthworms Leeches SEGMENTED WORMS ARE EUCOELOMATES

LEECHES Medical uses