Parasit - Lab Quiz 4

drraythe's version from 2015-08-31 03:50

Basics (goes past quiz 4 but good to know for the midterm)

Question Answer
How does a cestode eat things?No digestive system - absorbs things through skin
What are the infective larval stages called in cestodes? Where to they like to hang out?Metacestodes, outside of the intestines in the IH
What is the type of lifestyle of a cestode? Where do they adults live?Indirect, in the GI of the DH
What are the 3 main body parts of a cestode?Scolex ("head"), neck, Strobila ("body")
What is the scolex?Scolex = anterior part attaching to organs (looks like a head)
What is a rostellum?"Crown of thorns" hooks
Describe the features of the scolex of the order Cyclophyllidea4 suckers w/ or w/o rostellum (crown of thorns)
What is the neck?Undifferentiated where segments begin to develop
Describe the features of the scolex of the order Pseudophyllidea? & who is in this group(2)?(Spirometra, Diphyllobothrium) 2 bothria (longitudinal grooves become flattened to form attachment organs
What is the strobila?(The "wormy body" part) Contain proglottids (hermaphroditic segments containing male & female repro organs. Segments at the end of worm contain just gravid uterus)
What are proglottids?Hermaphroditic segments containing male & female repro organs. Segments at the end of worm contain just gravid uterus
Talk through the basic life cycle of a cestode, starting w/ eggEgg gets eaten by IH → metacestode. Metacestode ingested by DH → intestine → body digested away except for scolex & neck → scolex attaches to intestinal wall → start forming segments (strobilia). Segments form w/ mature repro organs → form eggs & sperm → fertilization. Once segments become gravid- detach & eliminated in DH feces → segments disintegrate to release eggs.
What are some variations on their asexual reproduction?Self-fertilization & cross fertilization (b/w segments) can occur
Describe how egg goes to metacestodeEgg contains oncosphere (1st stage larvae) → ingested by IH → egg broken down → oncosphere released → blood/lymph → predilection site → develop to metacestode stage
What is an oncosphere?1st stage larvae, the larvae inside the egg which, once "hatched" inside the IH, will turn into a metacestode
When does most pathogenesis occur in cestode infections?In the METACESTODE/LARVAL STAGE. Which means the INTERMEDIATE HOSTS are the 1s most harmed
What is a Cysticercus? Where is this?In the mammalian IH, it is a single fluid filled cyst w/1 invaginated scolex
What is a Coenurus? Where is this?In the mammalian IH, it is a fluid-filled cyst w/MANY invaginated scolices (each 1 can become mature tapeworm)
What is a Strobilocercus? Where is this?In the mammalian IH. Cysticercus (fluid filled cyst) w/Evaginated (NOT INvaginated) scolex → Already begins to form asexual proglottids (hermaphroditic segments) while in IH→ proglottids digested away by DH (so pure eggs released from DH)
What is a Hydatid cyst? Where is this? WHO does this? What are the types? What is hydatid sand?In the mammalian IH. Genus Echinococcus. Large fluid filled cyst w/many invaginated scolices (free or in bunches). Has a thick, laminated cell wall & germinal epithelium (brood capsules bud off of germinal epithelium). Brood capsules are full of heads (protoscolicieses) & when they burst, it is hydatid sand. The 2 kinds of hydatid cysts are Unilocular or alveolar (alveolar looks like a bunch of grapes)
What is a Cysticercoid? Where is this?In the ARTHROPOD IH. Evaginated scolex embedded in cyst (arthropods)
What is a Tetrathyridium? Where is this?In the invertebrate IH. Worm-like larvae w/ invaginated scolex. Only in mesocestoides in 2ND IH!!

Cyclophyllidea(order) Taeniidae(family)

Question Answer
What does a Taeniidae scolex look like?Scolex: 4 suckers +/- rostellum w/ 2 concentric rows of hooks
Descriptive feature of their proglottids?Unilateral genital pores alternating irregularly
Who can be the DHs of Taeniidae?Carnivores or humans
Metacestodes of Taeniidae can be in which 3 areas of the IH?In liver & peritoneal membranes or skeletal & cardiac muscle
How do you dx dogs & cats for Taeniidae?Oncospheres in feces. Also most have cysticercus (single fluid filled cyst w/1 invaginated scolex)

Taenia pisiformes

Question Answer
Who is the DH of T. pisiformes?Dogs & wild carnivores
Who is the IH of T. pisiformes?Rabbits & hares
What is the pathology in T. pisiformes?Cysticercus (cyst w/ 1 invaginated scolex) in liver & peritoneal cavity of rabbit, mainly mesentery
How to rememberYou'd be a pissy dog too, if your rabbit mesentery was full of nasty cysts

Taenia ovis

Question Answer
Who is the DH of T. ovis?Canids & wild carnivores
Who is the IH of T. ovis?Sheep
What is the pathology in T. ovis?In sheep, Cysticercus ovis in cardiac & skeletal muscle
How can you try to prevent T. ovis?De-worm dogs around sheep, dispose of sheep carcass properly
How to rememberOvis mutton (MUSCLE) never looked so a dog <3 <3 <3

Taenia hydatigena

Question Answer
What is the weird name for this species of Taenia?Necked bladderworm
DH of T. hydatigena?Canids & wild felids
IH of T. hydatigena?Cattle, sheep, swine, wild ungulates
What is the name of the larval stage in the IH? What does this metacestode do/cause (pathologically)?Cysticercus tenuicollis. Migrates through liver tissue & encysts on peritoneal membrane & causes hemorrhagic tracks. Can cause hepatitis cysticercosis, black disease (C. novyi) in intermediate host.
How can you tell if an IH has been previously exposed to T. hydatigena?Previously exposed host has greenish nodules on liver
How to rememberHydatigena will cause black hydrangeas (those poofy blue flowers) to explode from hoofed thing's liver & peritoneum, leaving bloody tracks everywhere. No wonder hoofed things dont like dogs & cats (dogs & cats say, 10/10 colons-taenicolis )

Taenia Taeniaeformis

Question Answer
DH of T. taeniformes?Cat
IH of T. taeniformes?Mouse/rodents
Describe (& name) the metacestode of T. taeniformes, & what does it do in the IH?Cysticercus fasciolaris. Cysticercus evaginates at day 42 (becomes Strobilocercus). Strobilocercus (cysticercus w/ evaginated scolex that has already begun to elongate & segment) in liver parenchyma
How to rememberTT was a cat w/ a mouse buddy, but that mouse buddy knew the answer to everything (42), & the strobilocercus popped out & exploded his liver w/ a strobing effect))

Taenia multiceps

Question Answer
DH of T. multiceps?Dog/wild canids
IH of T. multiceps?Sheep, goat (dwarf goat story), sometimes cattle
Describe the metacestode/pathology of T. multicepsCoenurus cerebralis in cranial cavity (Coenurus- Mature cyst in fluid filled cyst w/ clusters of scolices on internal walls). Neurologic signs of progressive space occupation slowly develop → TRUE GID.
What are some of the signs you see, caused from the pathology?Blindness, incoordination, walking in circles, head pressing, etc. If cyst superficial, softening of skull, death
How to rememberMulti jellyfish in a goats brain will make it go insane

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