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29 Cards in this Set
- Front
- Back
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What animals are in Phylum Platyhelminthes |
flatworms |
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% of types of Platyhelminthes |
80% parasitic (trematodes (flukes), cestodes) 20% free-living (planarians, turbellarians, acoels (maybe) |
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characteristics of platyhelminthes |
torso-ventrally flattened soft-bodies--no skeleton, hard structures |
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How many germ layers in Platyhelminthes and what this is called |
three--triploblastic endoderm from intestinal tract, ectoderm from epidermis, mesoderm from mesenchyme--muscle fibers, connective tissue |
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Platyhelminthes nervous system |
cephalized (head and brain--cerebral ganglion) paired, fused Ladder-like nervous system |
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Platyhelminthes musculature |
circular and longitudinal muscles worms can lengthen and contract |
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Platyhelminthes gas exchange |
no respiratory sys--just diffusion over body surface flattened body plan--surface area to volume--no cell can be too far from the outside, making flattened shape necessary |
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Platyhelminthes circulation |
no special structures for circulation flattened, usually small body allows nutrients, gases to reach tissues |
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Platyhelminthes excretory sys |
Protonephridia excretion and osmoregulation |
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Platyhelminthes excretory sys principles |
active transport and ultrafiltration all animals w/ excretory sys have both working together (use nephridia or protonephridia) or only active transport |
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Active transport |
secretion or reabsorption of substance by cells requires more energy than ultrafiltration (involves transport proteins) |
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Ultrafiltration |
from one compartment containing fluid to another--coelom or interstitial fluid Filter is extracellular matrix (ECM) |
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Where is extracellular matrix found |
lining pseudocoelom/gut tissue in pseudocoelomates |
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Characteristics of extracellular matrix for ultrafiltration |
fibrous retain larger molecules--proteins allows passage of water, ions, urea =basal lamina |
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Characteristics of ultrafiltration |
size selective--lets small molecules pass, large ones trapped has to be combined with active transport to reabsorbs water, salts, glucose, other small molecules animals needs |
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Protonephridia are also called |
flame cells |
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What does Turbellaria mean |
"little disturbance" ciliated epidermis most use waves of muscular contraction to move as well |
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Class Turbellaria feeding |
predators/scavengers muscular pharynx protrudes to capture food |
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Characteristic of Class Turbellaria Order Tricladida |
gut with three branches (tri-clad) |
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Characteristic of Class Turbellaria Order Polycladida |
Gut with many branches Often associated with other inverts (molluscs, sponges, corals) Largest free-living flatworms |
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Class Cestoda includes... |
Tapeworms |
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Class Cestoda feeding |
parasitic--endoparasites in digestive tract of verts |
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Cestode morphology |
no mouth--just absorb nutrients from environment--host gut--host finds, pre-digests food |
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Cestode movement |
circular and longitudinal muscle contraction--resist against mesenchyme, host gut wall |
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Species of Class Cestoda Order Cyclophyllidea Family Taeniidae |
Taenia pisiformis Dog tapeworm--adult worm in dogs, cats, other carnivores, rabbit intermediate host |
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Animals in Class Trematoda Subclass Digenea |
Trematodes, flukes |
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Class Trematoda Subclass Digenea feeding |
endoparasites of verts as adults--definitive hosts Parasitize inverts as larvae--intermediate hosts, esp. snails Few infect humans but can be devastating |
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Unique species in Class Trematoda Subclass Digenea |
Opisthorchis sinensis Chinese Liver Fluke--live in bile ducts of liver found throughout Asia, esp. Japan, China, Vietnam 20 million ppl infect infections via undercooked fish (freshwater) |
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Symptoms of O. sinensis |
erode epithelial lining of bile ducts--thickening, blockage of ducts, reduced liver function Severity depends on worm burden--most ppl, 10-20 worms: asymptomatic; higher numbers: ab pain, diarrhea, fever, liver cancer Treatment with Praziquantal |
