Chapter 14: Class Trematoda Flashcards
All trematodes are _____ flukes. Most adults are _______ of vertebrates. They resemble ectolcithal turbellaria but the tegument lacks ___ in adults. Some adaptations for parasitism include? (4)
- parasitic, endoparasites, cilia,
- Penetration glands
- glands to produce cyst material
- hooks and suckers for adhesion
- increased reproductive capacity
Some trematodes retain ancestral characteristics of what?
Alimentary canal gut) and reproductive, excretory and nervous system.
sense organs are poorly developed !
Subclass Digenea: - indirect life cycle in most....The first intermediate host is a \_\_\_. The definite or final host are \_\_\_\_\_\_\_. Organisms will \_\_\_\_\_ in this host. A 2nd or 3rd intermediate host may be required in the life cycle.
-mollusc(snail ex), vertebrates, reproduce sexually
General Digenean life cycle?
- Egg passes from _____ host in exreta and must reach ___.
- Hatches into a free swimming ______, the ______.
- Miracidium penetrates tissues of ____, transforming into a ____.
- Sporocyst reproduces _____ to form _____ or ______.
- Rediae reproduce asexually and form ____ or ____.
- Cercariae emerge from the snail and penetrate a second intermediate host or encyst on objects developing into _______ (juvenile flukes). The metacercaria develop into adults when eaten by the ____host.
- definitive, water
- ciliated larvae, miracidium
- snail (mollusc), sporocyst
- asexually, sporocyst or rediae
- rediae, or cercariae
- metacercaria, definitive/final host
Sheep Liver fluke - Fasciola hepatica (first digenean cycle described)
-Adult fluke lives in the ___ passageways in the ____ of sheep and other ruminants. Eggs are passed out in ___. Miracidia hatch and penetrate ___ to become ____. After ___ generations of rediae the ____ encyst on vegetation and await to be eaten by sheep. Once eaten, _______ develop into young flukes.
-bile, liver, feces, snails, sporocysts, 2, cercaria, metacercariae
Human Liver Fluke : Clonorchis Sinensis
- Most important human liver fluke! Common in china, japan and Southeast Asia. Can also infect ___, ____ and ___. Adult fluke is about ___-___ mm long with an ___ and ventral____. The digestive system includes: _____, _____,and two long__________. Excretory system has two ___________ with branches with _____cells. Nervous system includes two cerebral _____ and longitudinal ___with transverse ______. Males have ______, two _____ uniting to a ____, ____ and _____duct but no cirrus. Females have branched ____, and a short ____ duct joined by ducts from ______ receptacle and ______ at the ootype. The ootype is surrounded by ____ gland and the uterus extends to the _____ pore.
- cats, dogs, pigs, 10, 20, oral, sucker
- Digestive system: pharynx, esophagus and two long intestinal ceca
- Excretory System: two protonephridial tubules with branches with flame cells.
- Nervous system: two cerebral ganglia and longitudinal cords with transverse connectives.
- Males: testes, 2x vasa efferentia, vas deferens, seminal vesicle and ejaculatory duct.
- Females: branched ovary, short oviduct, seminal recptacle, vitellaria, Mehlis’, genital
Clonorchis Life Cycle?
-Adults live in __ passageways of humans and other fish-eating mammals. Eggs containing a complete ______ are shed into water via __. The eggs hatch only when ingested by snails of specific genera. Miracidium enters snail tissue and transforms into a ____. Sporocyst produces one generation of rediae which begin differentiation.
***main difference between sheep and human liver fluke is that the human one only produces one generation of rediae.
Rediae pass into the snail live continuing embryonation into tad pole like ____. Cercaria escape into the water encysting as ______ in a fishes muscles or under scales of the family _____. When a mammal eats this fish the cyst dissolves and flukes migrate up bile duct.
- bile, miracidium, feces, sporocyst
- cercaria, metacercariae, Cyprindae
Blood Flukes: Schistosoma -Common in what four parts of the world? -Sexes are ? -Three species exist: L> S.mansoni L>S.japonicum L>S.haemotobium (what do each affect?)
- Africa, South America, West Indies and the middle and Far East.
- separate sexes
a. venules of large intestine
b. venules of small intestine
c. venules of urinary bladder
Life Cycle of Shistosoma : Schistosomiasis (disease name)
- Eggs discharge in human ___ or ___.
- In water, eggs hatch as ciliated ___.
- Must contact a particular species of snail to survive. In the snail they transform into ___.
- Sporocyst produce ___ directly. (BIG DIFF)
- Cercariae escape the snail and swim until they contact bare human skin. They pierce the skin and shed their ___.
- Enter blood vessels and migrate to the _____ portal blood vessels.
- Develops in the ____ and they migrate to target sites.
- Eggs are released by females are extruded through __ or ___ lining and exit with ___ or ___.
- Eggs that remain behind will become centers of _____.
- feces or urine
- miracidia
- sporocyst
- cercariae
- tail
- hepatic portal blood vessels
- liver
- gut, bladder lining and exit with feces or urine
- inflammation
Eggs of S.mansoi and S.japonicum damage what?
Eggs of S.haematobium damage?
Reduce infection rate by?
Schistosome dermatitis ?
- damage intestinal wall
- damage bladder wall
- proper disposal of human wastes!
- occurs when cercariae penetrate an unsuitable host such as humans….aka swimmers itch
Gynecophoric canal??
-in males for schistosoma….blood flukes…its a ventral groove posterior to ventral sucker…embraces the long slender female for copulation yo
