Transcript Worms - local.brookings.k12.sd.us

Worms
What’s Eating You for Dinner ?
http://curezone.com/image_gallery/parasites/all/default.asp?i=1&n=75
FLATWORMS
PYLUM: Platyhelminthes
FREE LIVING
Planaria
PARASITIC
Flukes & Tapeworms
FLATWORMS ARE ACOELOMATES
PLANARIA
NOT
PARASITES
GASTROVASCULAR CAVITY
(Combination Digestive & circulatory)
• One
opening
digestive
cavity
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 look
like little “flames”
REPRODUCTION
SEXUAL(hermaphrodites but
trade with partner)
ASEXUALcan use regeneration to
grow a new organism
from parts
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; eggs travel to intestines or bladder
Immature worm
burrows through skin
into blood vessels
Eggs leave body in
urine or feces
Larvae grow tails
and leave snail
Larva hatches from
egg & infects snail
(intermediate host)
PARASITIC FLATWORM
Schistosoma
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
Dog tapeworm
PARASITIC FLATWORM
(lives in HOST animal intestines)
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
PROGLOTTIDS
hermaphroditic reproductive structures
(contain both male & female sex organs)
EGGS INSIDE
http://curezone.com/image_gallery/parasites/all/default.asp?i=65&n=75
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
EX: BEEF TAPEWORM
Humans eat
undercooked meat
containing cysts
Adults attach
inside intestines
and absorb
digested food
Proglottids burst
releasing eggs with
larvae inside on ground
Cows eat grass;
larvae travel through blood vessels;
make cysts in muscle
Proglottids are
released in feces
http://net.unl.edu/wonderwise/12parasi/a-para.htm
ROUND WORMS
Nematoda
Ascaris
Trichinella
Hookworms
Pinworms
Filarial worms
http://curezone.com/image_gallery/parasites/all/default.asp?i=1&n=75
ROUND WORMS ARE PSEUDOCOELOMATES
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



Larvae are coughed
up & swallowed;
Return to intestines,
mature, & mate
ASCARIS
LIFE CYCLE

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
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 WORMS
Trichinella
Humans infected by
eating undercooked
meat containing cysts


Cysts release
larvae that burrow
into intestinal wall &
mature
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 –
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= _______________________
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
ELEPHANTIASIS
Common in
tropical countries
Adult worms can
grow to 4” long
ELEPHANTIASIS
Mosquito picks up
larvae from blood
when it feeds
Adult worms live
and reproduce in
lymph vessels

Larvae develop into
juveniles inside mosquito

Mosquito injects
juveniles which
migrate to lymph
nodes and mature
http://www.acm.uiuc.edu/sigbio/project/updated-lymphatic/lymph3.html
FILARIAL
ROUND WORMS
DOG HEARTWORM
Carried by
mosquitoes
http://curezone.com/image_gallery/parasites/all/default.asp?i=66&n=75
FILARIAL ROUND WORMS
Loa loa
Found in AFRICA
http://www.biosci.ohio-state.edu/~parasite/loa.html
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 WORMS
Guinea worm
http://curezone.com/image_gallery/parasites/all/default.asp?i=5&n=75
Found in AFRICA
http://curezone.com/image_gallery/parasites/all/default.asp?i=6&n=75
PARASITIC ROUND WORM
http://curezone.com/image_gallery/parasites/all/default.asp?i=5&n=75
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 worms
migrate to skin
http://curezone.com/image_gallery/parasites/all/default.asp?i=6&n=75
PARASITIC ROUND WORMS
Hookworms
http://curezone.com/image_gallery/parasites/all/default.asp?i=1&n=75
http://www.biosci.ohio-state.edu/~parasite/placoconus.html
Live in intestine;
feed on BLOOD
Ancylostoma
HOOKWORM LIFE CYCLE
Larvae are coughed
up & swallowed;


Larvae enter body by burrowing
through skin on feet & travel to lungs


Return to intestines;
mature & mate

Adult worms live in
intestine and feed on blood
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
• Worldwide
500 million people
are infected with
pinworms
Grow up to ½ inch long
http://curezone.com/image_gallery/parasites/all/default.asp?i=16&n=75
Parasitic ROUND WORMS
Pinworms
• 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 WORMS
Annelida
FREE LIVING
Earthworms
PARASITIC
Leeches
SEGMENTED WORMS ARE EUCOELOMATES
LEECHES
Medical uses