METAZOANS (Cestodes/TAPEWORMS) Flashcards
memorization
Anterior end of the body; muscular organ for attachment; “hold fast”
Scolex
2 types of scolex:
- Bothriate
- Acetabulate
Spoon, spatulate, or spindle-shaped scolex; has suctorial grooves/sucking grooves’ order pseudophyllidea
Bothriate
Quadrate scolex containing 4 muscular suckers; Rostellum; projection at the apex of the scolex armed with hooks or spines
Acetabulate
Part behind the scolex; unsegmented; region of growth where strobilation begins
Neck
Chain of segments (proglottids)
Strobila
The immature segment (immature proglottid) is located at:
near the neck
Segment that are filled with eggs; other reproductive organs have atrophied; uterus remain:
Gravid segment
Proglottid detaches from the body to release the eggs; order Cyclophyllidea:
Apolytic proglottid
Has uterine pores; detaches only after the eggs are released:
Anapolytic proglottid
Common name/other name of Diphyllobothrium latum:
“fish tapeworm” / |”broad tapeworm”
Common name/other name of Taenia solium
“Pork tapeworm”
Common name/other name of Taenia saginata
“Beef tapeworm”
Common name/other name of Hymenolepis nana:
“Dwarf tapeworm”
Common name/other name of Dipylidium caninum
“Dog & cat tapeworm”
Common name/othername of Echinococcus granulosus:
“Hydatid tapeworm”
Tapeworm that has no rostellum or hooks but has 4 suckers:
Taenia saginata “beef tapeworm”
Knob0like, rudimentary rostellum without hooks:
Hymenolepis diminuta
Conical refractile with 1-7 circlets of hooks, has rostellum:
Dipylidium caninum
Globular, rostellum with double crown of 30-36 hooks
Echinococcus granulosus
Knob-like, short, invaginated rostellum with single row of 20-30 hooks:
Hymenolepis nana
Common name/other name of Hymenolepis diminuta:
“Rat tapeworm”
Spatulate; No rostellum and hooks:
Diphyllobothrium latum
Tapeworms that have broader than long proglottids:
- Diphyllobothrium latum
- Hymenolepis nana
- Hymenolepis diminuta
Tapeworms that have Longer than broad proglottids:
- Taenia solium
- Taenia saginata
- Echinococcus granulosus
Tapeworm proglottid that has Vase, barrel, cucumber seed, pumpkin seed-shaped with compartmented egg clusters:
Dipylidium caninum
Tapeworm with Rosette-shaped, central uterus:
Diphyllobothrium latum
Tapeworm with7-15 lateral branches:
Taenia solium
Tapeworm with 15-30 lateral branches:
Taenia saginata
Tapeworm with sacculate (sac-like) uterus:
- Hymenolepis nana
- Hymenolepis diminuta
Tapeworm with reticulate uterus with egg capsules:
Dipylidium caninum
Tapeworm with 12-15 lateral branches:
Echinococcus granulosus
Lateral with REGULAR alternation of genital pore:
Taenia solium
Lateral with IRREGULAR alternation of genital pore:
Taenia saginata
Tapeworm with Bilateral/Double-pored genital pore:
Dipylidium caninum
Unilateral genital pore:
- Hymenolepis nana
- Hymenolepis diminuta
Difference of H. nana and H. diminuta ova:
H. nana:
- 2 polar thickenings where 4-8 filaments arise
H. diminuta:
- 2 polar thickenings where NO filaments arise
Tapeworm ova that has 8-12 eggs enclosed in a membranous capsule:
Dipylidium caninum
Operculated; abundant yolk granules, small knob at abopercular end:
Diphyllobothrium latum
Cystic larvae of T. solium:
Cysticercus cellulose
Cystic larvae of T. saginata:
Cysticercus bovis
Tapeworm spp that has two (2) intermediate host:
Diphyllobothrium latum
1st: copepods
2nd: fish
Tapeworms where man is incidental host:
- Hymenolepis nana
- Hymenolepis diminuta
- Dipylidium caninum
- Echinococcus granulosus
MOT of D. latum:
Ingestion of plerocercoid (sparganum) on the flesh of infected fish
Pathogenesis/Disease caused by D. latum:
- Diphyllobothriasis
- Megaloblastic anemia 9Vit. B12 deficiency)
Diphyllobothrium latum
IS:
DS:
Diphyllobothrium latum
IS: Plerocercoid (sparganum) present in infected fish
DS: Ovum
New name of Diphyllobothrium mansoni:
Spirometra mansoni
In Spirometra mansoni, man is the _______ host:
Incidental host
Definitive host of Spirometra mansoni:
Cats and Dogs
Pathogenesis of Spirometra mansoni:
Sparganosis
Extraintestinal infection of Spirometra mansoni:
Most commonly in:
1. Eyes
2. Thorax
3. Abdomen
MOT of T. saginata:
T. saginata
MOT: ingestion of Cysticercus bovis in infected beef
Taenia saginata
IH:
DH:
Taenia saginata
IH: Cow
DH: Man
Pathogenesis of T. saginata:
Taeniasis (adult stage infection)
Intestinal obstruction
MOT of T. solium:
Taenia solium
MOT: ingestion of Cysticercus cellulose in infected pork; ingestion of eggs; autoinfection possible
Pathogenesis of Taenia solium:
- Taeniasis (adult stage infection)
- Cysticercosis (Larval stage infection)
T. solium taeniasis
IH:
DH:
IS:
T. solium taeniasis
IH: Pig/Swine
DH: Human
IS: Cystic larvae
T. solium cysticercosis
IH:
IS:
T. solium cysticercosis
IH: Human
IS: Egg/Ovum
Extraintestinal infection of Cysticercosis caused by T. solium;
Extraintestinal infection (T. solium)
1. Brain
2. Eyes
3. Subcutaneous tissue
Hymenolepis nana
MOT:
IH:
DH:
AH:
IS:
DS:
Hymenolepis nana
MOT: ingestion of cysticercoid in an infected rat flea
IH: Rat flea
DH: Man
AH: Rat (accidental host)
IS: Embryonated egg
DS: Embryonated egg
Note: can cause INTERNAL AUTOINFECTION - some eggs can hatch inside the intestine
Hymenolepis diminuta
MOT:
IH:
DH:
AH:
Hymenolepis diminuta
MOT: ingestion of cysticercoid in an infected arthropod
IH: Arthropod
DH: Rat
AH: Man
Note: Autoinfection is not possible
Diagnostic problem for Dipylidium caninum:
gravid proglottid resemble rice grains (dry) or cucumber seeds (moist)
Echinococcus granulosos
MOT:
IH:
DH:
Accidental Host:
DS:
Echinococcus granulosos
MOT: ingestion of egg
IH: Sheep
DH: Canines
Accidental Host: Man
DS: Hydatid cyst in tissue (usually liver)
Diagnostic procedures for Echinococcus granulosus infection:
- Tissue biopsy
- CT scan (& other radiologic procedures)
- Casoni’s intradermal test
Echinococcus multiocularis
IH:
DH:
Accidental Host:
MOT:
Echinococcus multiocularis
IH: Rodents (e.g. mice)
DH: Foxes, wolves (canines)
Accidental Host: Man
MOT: Ingestion of egg (ova)
Note: Extraintestinal infection - most commonly infects the LIVER
