Lab 6 Flashcards
Trematodes I (122 cards)
1
Q
helminth-
A
worm
2
Q
platyhelminthes-
A
flatworms
3
Q
platyhelmintes are a very old lineage; fossil evidence in:
A
Permian sandstone tracks
4
Q
General flatworm characteristics:
- What kind of symmetry?
- __________ flattened
A
- bilateral
- dorsoventrally
5
Q
do flatworms have a body cavity?
what are their internal organs imbedded in?
A
no
parenchyma (tissue)
6
Q
do flatworms have a nervous system?
A
yes
7
Q
do flatworms have a digestive system?
A
yes (ends in blind sac)
8
Q
do flatworms have an excretory system?
A
yes
9
Q
what kind of cells make up the flatworm excretory system?
A
flame cells
10
Q
what body systems are absent from flatworms?
A
circulatory, respiratory, skeletal
11
Q
what is the flatworm rate of reproduction comparative to other animals?
A
it is prolific. Its whole life cycle is geared towards producing lots of offspring
12
Q
what 3 reproductive patterns are found in flatworms?
A
monecious, dioecious, ectolecithal
13
Q
what reproductive pattern is found in most flatworms?
A
monecious
14
Q
monecious-
A
hermaphroditic reproductive style
15
Q
monecious worms can do what two kinds of fertilization?
A
- self fertilization
- cross fertilization between two hermaphrodites
16
Q
dioecious-
A
two sexes (schistosomes)
17
Q
ectolecithal-
A
yolk supplied by cells outside the ovum
18
Q
most flatworms are/are not parasitic?
A
are
19
Q
trematodes are _____ flukes; _____ flukes; _____ flukes
A
blood; intestinal; tissue
20
Q
Digenetic:
A
-Minimum of two hosts: definitive and intermediate
21
Q
Trematodes:
- 1st intermediate host usually a _________
- –May have more than one intermediate host
- Definitive host:
A
- mollusk (such as a snail)
- a vertebrate (sexual reproduction occurs)
22
Q
Trematodes:
- ____ in shape and dorsoventrally flattened
- __ sucker(s) usually: (name them)
A
- oval
- 2
- oral (at anterior end) surrounding the “mouth”
- acetabulum (ventral sucker)
23
Q
Trematodes:
- _________ is active
- actively secretes ___________ to block___________
A
- tegument
- neutralizing substances
- host responses
24
Q
- digestive tract of trematodes:
- primitive
- Name 4 components and describe them
A
mouth within oral sucker
pharynx
esophagus
intestinal ceca (end as blind sacs - no stomach, no anus)
25
Trematodes:
- Nutrition obtained (varies from species to species)
- -some feed by_____________
- -some nutrients can be absorbed through ________
- - (4 places) contents as food (varies with species)
- forming “plug” with oral sucker and pumping tissue into pharynx
- tegument
- Blood, mucus, tissue or gut
26
Trematodes:
- primitive excretion system (via ______, ________)
- muscular: ______, ______ and _____ muscle tissues
- tegument, glands
| - longitudinal, cross and diagonal
27
Trematodes:
| Reproductive Tract: hermaphroditic (exception: _______)
schistosomes
28
Trematodes:
MALE REPRODUCTIVE SYSTEM:
-name the 4 organs
- _ testes typically -- sperm leaves testis through __________
- testes, vas efferens, vas deferens, cirrus pouch
- 2
- vas efferens
29
Trematodes:
FEMALE REPRODUCTIVE SYSTEM:
-Ovary is single (and stains ____)
-___________ produce the yolk
-Uterus extends to ________ and can be what 3 shapes?
-ovary usually located where?
-uterus usually full of eggs and covers _______
- vitelline cells are produced by ________ which are connected by _____________
-vitelline glands are located down ____ side(s) of an adult fluke
- dark
- Vitelline cells
- genital pore
- long, coiled or folded
- right behind or right before uterus
- intestine
- vitelline glands
- vitelline ducts
- both
30
-should be able to identify what trematode sex organs under microscope?
testes, ovary, uterus, vitelline glands and intestines (ceca) in adult flukes
31
General forms in life cycle:
| Ovum-->(1)-->(2)-->(3)-->(4)-->(5)-->(6)
Ovum-->miracidium-->sporocyst--> redia-->cercaria-->metacercaria-->adult
32
-ovum (egg)-
is really an embryo (miracidium) enclosed in a capsule
33
operculum–
opening at one end of egg through which larva will escape
34
(_________ eggs are not operculated)
blood flukes
35
Miracidium:
-ciliated free-swimming larva hatched from ovum
36
-(3) are all required for development and hatching of larva in external environment
water, oxygen and temperature
37
-miracidium have limited time to:
find snail host (a few hours)
38
upon finding a snail host, the miracidium penetrates and burrows in via ________ (about 30 minutes). Except that some species require ___________ for hatching of miracidium which will penetrate through _________
- cytolysis
- ingestion of egg
- gut wall of snail
39
miracidium loses ______ upon penetration of host
cilia
40
-__________ is a chemical attractant for miracidia
mucus of snail “trail”
41
_______ results from metamorphosis of miracidium as it elongates to form a __________
- Sporocyst
| - sac-like structure
42
The sporocyst has no _____, no ______, ________ nutrients from host
- mouth
- digestive system
- absorbs
43
embryos will develop asexually within a:
“germinal sac”
44
-sporocyst may produce ________________ or
| it may give rise to ________ or to ____________
- more generations of sporocysts: daughter sporocysts
- the next stage redia (plural = rediae)
- cercaria (depending upon species of fluke involved)
45
Redia:
different form of a germinal sac
46
Redia burst out of sporocyst in some species, leave by ________ in others
birth pore
47
Redia:
- active in host (crawls around)
-___________ digestive system (muscular pharynx and short sac-like gut) and
actively _____________
- they may also prey on _______________ within snail host
- rudimentary
- feeds on host tissues
- sporocysts of their own or other species
48
Redia:
-embryos develop within and� form _____________ OR
__________, which then leave host via _________
- daughter redia and repeat process
- form cercaria
- birth pore
49
Trematode infective stage for definitive host:
cercararia
50
Cercararia:
| -usually “__________” but can survive only briefly (must find a host quickly)
-free-swimming
51
Cercararia:
- usually have a ______ to aid in swimming
- _______ forms creep about until eaten
- some stay ___________ until __________
- tail
- tailless
- within sporocyst or redia that produced them
- snail host is eaten
52
Cercararia:
- have ___________ but doesn’t feed
- have __________ to aid in penetration of definitive host
- considered a __________
- mouth and digestive system
- penetration glands
- juvenile fluke
53
-stage not found in all fluke life cycles e.g., blood flukes do not have it.
Metacercaria
54
Which trematode form is encysted?
- -can be in or on intermediate host
- -some encyst on ___________ or other things in water
- Metacercararia
| - aquatic vegetation
55
Cercararia to metacercararia:
- 1st step:
- 2nd step:
- what is purpose of doing this stage?
- value of this stage:
-lose the tail
-form cyst wall (thick if on vegetation, thinner if inside 2nd intermediate
host)
-cysts within intermediate hosts survive longer, can absorb nutrients from host.
-a means of transmission to definitive host that does not feed on the intermediate host or is not in environment of mollusk host.
56
- the metacercararia must be ingested for what to occur?
| - migration within host to the preferred niche will vary with ___________
- excystment in gut and development into adult fluke
| - species of fluke
57
-_______ reproduction will occur in adult flukes
sexual
58
```
Fasciola hepatica:
-called a "________"
-Distribution:
-Intermediate host:
-Definitive host:
-causes- “_______”
- Infective stage:
- Host niche:
```
- liver fluke
- Europe, USA, S America, China, Africa, Central America
- aquatic snail Lymnea sp
- cattle,sheep, humans
- Liver Rot
- metacercaria
- liver and bile duct
59
Fasciola hepatica:
| 2 hosts: _____ intermediate host and _______ definitive host
- snail
| - vertebrate
60
Ova (must be in ____ to embryonate and hatch and takes ____ days)
- water (Fasciola hepatica)
| - 9-15
61
_______- phototrophic and must quickly find and penetrate snail host; asexually
produces
Miracidium (Fasciola hepatica)
62
_____- asexual development produces rediae
Sporocyst
63
Redia produce ________ which then produce ______
- daughter rediae generations
| - cercaria
64
(Fasciola hepatica)_______- free-swimming form (has unforked tail)
Cercaria
65
(Fasciola hepatica)________- formed when cercaria attach to aquatic vegetation, lose tail and form
cyst wall
Metacercaria
66
(Fasciola hepatica)_______- When eaten by definitive host, excyst in small intestine, penetrates gut wall, and travels toward liver
Metacercaria
67
(Fasciola hepatica)________-migrates in liver of definitive host (sheep, cattle, human)
adult fluke
68
Fasciola hepatica: adult fluke feeds on what?
liver cells, lining of bile duct, blood
69
Fasciola hepatica: adult fluke produces _________ eggs which pass down _____and out with feces
- operculated
| - bile duct
70
Fasciola hepatica
| “Fascioliasis” symptoms include:
- obstruction of bile duct
- liver enlarges
- can form large liver abcesses
- eosinophilia (numbers of circulating eosinophils rise)
71
Fasciola hepatica
| what causes the symptoms of fascioliasis?
the migration of adult flukes creates the clinical symptoms and pathology
72
Fasciola hepatica
How is it transmitted to humans?
Where is this a big problem?
still goes back to fecal contamination of water source!
- drink water containing metacercaria or eat aquatic vegetation such as watercress with metacercaria attached
- the orient
73
Fasciola hepatica
| -fascioliasis in humans is ___ in USA, even though parasite is ______
- rare
| - common
74
Fasciola hepatica
Liver: damage and _______ from migration of adults in liver and bile duct
-in slaughter animals (sheep and cattle), infected livers are always condemned
-scarring (fibrosis)
75
Fasciola hepatica
Morphology:
-____-shaped, large with _____-shaped projection on anterior end “anterior cone and shoulders” -help ID this fluke
-extensive ______ –fills most of posterior space
-tegument covered with __________
- leaf
- cone
- vitellaria
- scale-like spines
76
Fasciola hepatica
| When looking at the adult, take notice to:
- anterior cone and shoulders (oral sucker at end of cone)
- Testes large and branched, in tandem behind ovary (hard to see)
- Branched intestine up by head (can see it)
77
```
Fasciola magna
basically the same as hepatica, but with a few key differences:
Definitive host:
Morphology:
Distribution:
```
- also found in DEER but not in humans
- larger and with no anterior cone and shoulders
- only found in north america and europe
78
```
Fasciola gigantica
Very similar to hepatica with a few key differences:
Definitive host:
Morphology:
Intermediate host:
Distribution:
```
- not in humans
- bigger
- different than snails that hepatica uses
- asia, africa, hawaii
79
Fasciolopsis buski is a fluke of what organ?
small intestine
80
What is the largest fluke to infect humans?
Fasciolopsis buski
81
Fasciolopsis buski produce how many eggs per day?
25,000
82
Fasciolopsis buski's intermediate host is:
snails
83
Fasciolopsis buski metacercararia are found where?
underwater vegetation
84
```
Fasciolopsis buski morphology:
size:
ovary/testes shape/size/position:
intestinal ceca branched/not branched?
size and location of acetabulum:
vitellaria?
```
- large (20-75 mm long)
- branched ovary anterior to testes/branched testes in posterior end
- ceca is not branched
- acetabulum large and close to oral sucker
- extensive
85
Fasciolopsis buski clinical signs:
- adult flukes feed on intestinal epithelial cells
| - can cause ulceration, hemorrhage and abcesses of small intestine
86
Clonorchis sinensis aka:
“Chinese liver fluke”
87
what is the vitellaria?
a yolk gland responsible for providing yolk for eggs
88
Clonorchis sinensis enemic in:
China, Japan, Viet Nam, Korea
89
Clonorchis sinensis reservoir hosts:
dogs and cats
90
Clonorchis sinensis
- 1st intermediate host:
- 2nd intermediate host:
- Definitive host:
- Infective stage for definitive host:
- aquatic snail
- fresh water fish (esp cultivated grass carp)
- man, dog, cat
- metacercaria in 2nd intermediate host
91
Clonorchis sinensis
Niche:
- Adults ____-fertilize and eggs pass out with feces.
- lumen of bile duct (adults feed on bile duct epithelium)
| - self
92
Clonorchis sinensis:
Ovum must be eaten by ______. Miracidium hatches and penetrates into gut wall and transforms into _________, which gives rise to _______, which produce ______ with eye spots. Released ______ hang upside down in water, slowly sink to bottom and then swim back up. If it contacts a suitable host – ____, it infects the fish and encysts as a ________. For the cycle to continue, a __________ must eat the 2nd intermediate host raw or incompletely cooked. The metacercaria excysts and migrates to liver where it crawls up the ______. Adults pass eggs into bile duct which opens into the intestine. Eggs out with feces.
Ovum must be eaten by snail host. Miracidium hatches and penetrates into gut wall and transforms into sporocyst, which gives rise to rediae, which produce cercaria with eye spots. Released cercaria hang upside down in water, slowly sink to bottom and then swim back up. If it contacts a suitable host – fish, it infects the fish and encysts as a metacercaria. For the cycle to continue, a definitive host must eat the 2nd intermediate host raw or incompletely cooked. The metacercaria excysts and migrates to liver where it crawls up the bile duct. Adults pass eggs into bile duct which opens into the intestine. Eggs out with feces.
93
Clonorchis sinensis
Light infection:
Moderate to heavy infection –
- chronic infections have been associated with the development of ____________
- asymptomatic –no disease
- clinical disease
- cholangiocarcinoma (bile duct cancer)
94
Clonorchis sinensis
| Dx:
eggs in stool (are very small, see size comparison chart in handout)
95
Clonorchis sinensis morphology
- Adults have______ appearance
- sucker morphology?
- shape and location of testes?
- Tegument lacks ______
- lancet
- Weakly developed suckers
- Branched testes, in tandem near posterior end
- spines
96
```
Heterophyes heterophyes
size:
host niche:
host:
distribution:
```
- tiny (1 mm long)
- intestine
- all are considered potential human pathogens
- africa, asia, middle and far east
97
Heterophyes heterophyes life cycle:
eggs containing ________ in feces, which must then be eaten by _______ where they then penetrate through its gut and form a ______, which produces a bunch of _______, which each produce a bunch of ______, which then hatch and are released to the water in search of _____. When they penetrate the skin of a fish, they encyst in muscle as _______, which are then ingested by a def. host and excyst in the ____ intestine and burrow ______ to produce eggs which are shit out.
eggs containing miracidium in feces, which must then be eaten by snail where they then penetrate through its gut and form a sporocyst, which produces a bunch of rediae, which each produce a bunch of cercaria with eye spots, which then hatch and are released to the water in search of fish. When they penetrate the skin of a fish, they encyst in muscle as metacercaria, which are then ingested by a def. host and excyst in the small intestine and burrow between villi to produce eggs which are shit out.
98
which two species' cercaria have eye spots?
Heterophyes heterophyes and Clonorchis sinesis
99
Heterophyes heterophyes clinical disease occurs with heavy infection. Can cause: (4)
gastric distress, malaise, fatigue, diarrhea
100
Heterophyes heterophyes fatal cases on record:
- went to heart and damaged valves and heart muscle causing heart failure.
- -Both adults and eggs have been involved in cardiac pathology - eggs in brain and spinal cordneurological problemsfatal cases
101
Dicrocoelium dendriticum aka. the:
“the Lancet fluke”
102
```
Dicrocoelium dendriticum
unique morphology:
def. host:
Distribution:
niche:
```
- body pointed at both ends and simple ceca
- livestock
- North America, Europe, Asia, Australia
- bile duct
103
Dicrocoelium dendriticum
1st intermediate host:
2nd intermediate host:
- land snail (Cionella lubrica)
| - common brown ant (Formica fusca)
104
Dicrocoelium dendriticum
| is there an aquatic stage for this worm?
NO, only uses land snails
105
Dicrocoelium dendriticum life cycle pt. 1:
Eggs in feces are eaten by a snail and hatch. The _______ becomes a _______, which multiplies to form daughters that then produce ________, which accumulate in ______, which irritates tissues and cause the snail to surround them with ______, which is expelled to environment (it protects cercararia from ______) where it is then eaten by ______.
Eggs in feces are eaten by a snail and hatch. The miracidium becomes a sporocyst, which multiplies to form daughters that then produce cercaria, which accumulate in the snails lung, which irritates tissues and cause the snail to surround them with a slime ball, which is expelled to environment (it protects cercararia from drying out) where it is then eaten by brown ants.
106
Dicrocoelium dendriticum life cycle pt. 2:
Cercaria become _______ in the tissues of the ant, but one or two _______ migrate to the ___________ (brain) of the ant. The parasite in this location creates behavioral changes in the ant. Infected ants climb up on blades of grass at night instead of returning to ant hill. Their mandibles fasten on to the blade of grass and remain locked onto the plant overnight. � This behavior enhances the possibility of ingestion of the ant (and thus the parasite) by the ________ host. In definitive host, metacercaria excyst, migrate to _____ and climb up _____. There is not trauma to gut wall or liver by migrating juveniles. Damage: general _________ by adults in bile duct.
Cercaria become metacercaria in the tissues of the ant, but one or two cercaria migrate to the superior nerve ganglion (brain) of the ant. The parasite in this location creates behavioral changes in the ant. Infected ants climb up on blades of grass at night instead of returning to ant hill. Their mandibles fasten on to the blade of grass and remain locked onto the plant overnight. This behavior enhances the possibility of ingestion of the ant (and thus the parasite) by the definitive host. In definitive host, metacercaria excyst, migrate to liver and climb up bile duct. There is not trauma to gut wall or liver by migrating juveniles. Damage: general biliary dysfunction by adults in bile duct.
107
Dicrocoelium dendriticum Dx:
eggs in stool
108
Dicrocoelium dendriticum identification of adults, Look for:
unbranched (lobate) testes anterior to ovary
109
Prosthogonimus macrorchis aka:
“oviduct fluke of birds”
110
Prosthogonimus macrorchis
1st Intermediate host:
2nd intermediate host:
Definitive host:
- snail
- dragon fly nymph
- bird
111
Prosthogonimus macrorchis life cycle:
Embryonated egg does not hatch until ________. Sporocysts produce cercariae which enter ____ of dragon fly nymph and encyst in _____. When nymph metamorphoses into adult dragon fly, _______ remain in muscle. When dragon fly is eaten by bird, _______ excyst in small intestine and migrate down to ______ where they enter the _______ or the _____. Infection in male bird ends when _________. In female, effects are detrimental to the reproductive success of bird host species. Damage to the ______ in female birds can result in decreased or complete prevention of egg laying.
Embryonated egg does not hatch until eaten by snail. Sporocysts produce cercariae which enter anus of dragon fly nymph and encyst in muscle. When nymph metamorphoses into adult dragon fly, metacercaria remain in muscle. When dragon fly is eaten by bird, metacercaria excyst in small intestine and migrate down to cloaca where they enter the bursa of Fabricius or the oviduct. Infection in male bird ends when bursa atrophies. In female, effects are detrimental to the reproductive success of bird host species. Damage to the oviduct in female birds can result in decreased or complete prevention of egg laying.
112
Prosthogonimus macrorchis identifying characteristics:
huge testes and concentrated vitellaria
113
Paragonimus westermani aka:
human lung fluke
114
Paragonimus westermani
Distribution:
Has very diverse, numerous reservoir hosts
Southeast Asia, Africa, South America
115
Paragonimus kellicotti
- Found in _________
- Numerous _______ definitive hosts, including _____
- North America
- mammalian
- man
116
Paragonimus spp.
Host Niche:
1st Intermediate host:
2nd intermediate host:
- lungs (flukes encapsulated in pairs – flukes induce host formation of fibrotic capsule)
- aquatic snail
- crustacean such as crayfish or crab
117
Paragonimus spp.
snail host lives in fast-moving streams – this decreases chances of a miracidium encountering snail host but this is offset by:
the number of eggs produced by adults.
118
Paragonimus spp. Life Cycle:
Eggs coughed up and out with bloody sputum. Some may be ________ and pass out with feces into water.
_______ penetrates aquatic snail and transforms into ________, which gives rise to _____, which produce ________ (have a knob-like tail). Released cercaria don’t swim, instead ________. Cercariae attach to crayfish or crabs and encyst as ________ in viscera and muscles. Definitive host eats raw crayfish or crab and metacercaria excyst in small intestine. Juvenile flukes penetrate through gut wall and migrate through peritoneal cavity,
penetrate through _______ and into _____ and ________.
_____ fertilization between pairs is the rule in Paragonimus sp.
Eggs coughed up and out with bloody sputum. Some may be swallowed and pass out with feces into water.
Miracidium penetrates aquatic snail and transforms into sporocyst, which gives rise to rediae, which produce microcercous cercaria – have a knob-like tail. Released cercaria don’t swim, instead creep along bottom.
Cercariae attach to crayfish or crabs and encyst as metacercaria in viscera and muscles. Definitive host eats raw crayfish or crab and metacercaria excyst in small intestine. Juvenile flukes penetrate through gut wall and migrate through peritoneal cavity,
penetrate through diaphragm and into lungs and bronchioles.
Cross fertilization between pairs is the rule in Paragonimus sp.
119
Which species is here in Louisiana in crawfish?
Paragonimus kellicotti
120
Paragonimus spp. pathology. The damage they cause:
lung lesions “pseudotubercles” (similar in appearance and symptoms to tuberculosis)
121
Paragonimus spp identification on slides
-size/shape/color?
-testes/ovaries shape and location?
Egg morphology:
- small, brown, coffee bean shaped
| - thick testes oblique to each other/finger like lobed ovary. testes are posterior to ovary
122
Paragonimus spp. Dx.
eggs in sputum
