W6- Phylum Platyhelminthes (Class Cestoda)

Question 1

What is class Cestoda known as?

Answer 1

they are Tape worms from phylum Platyhelminthes

Question 2

Characterics of class cestoda

Answer 2

endoparasites(lives inside tissues of host)

• multisegment, dorsoventrally flattened tape-like worms
• NO digestive system
• hermophrodites (M+F)

Question 3

Class Cestoda morphology

Answer 3

3 parts: Scolex(head), colon(neck), Strobila(body).
- Scolex: organ of attachment to intestinal mucosa of def host.
- Colon: region of grown, budding of new proglottids.
- Strobila: composed of a chain of proglottids.
> immature proglottids- near neck, repro organs not well developed.
> mature segment- every segment contains both M+F sex organs.
> gravid segment- at hind end, filled by uterus w/ egg. leave host in feces.

Question 4

What are proglottids?

Answer 4

they are the segments that make up body of tape worms, they contain sexually mature reproductive system.

Question 5

What is strobilation?

Answer 5

asexual process of forming segments. each segment had testes and ovaries

Question 6

what is Diphyllobothrium latum known as?

Answer 6

fish or broad tapeworm

Question 7

what does Diphyllobothrium latum cause

Answer 7

Diphyllobothriasis

may cause vit B12 deficiency + megaloblastic anemia.

Question 8

Diphyllobothrium latum habitat

Answer 8

in small intestine/ ileum

Question 9

Diphyllobothrium latum morphology

Answer 9

20m
scolex has 2 bothria (slit like grooves) for attachment to the intestine.
Proglottids are wider than
long.(3000-4000 prog) mature prog has M+F repro organs.
Gravid proglottids= flower like uterus.
ovary is bi-lobed
testes= minute follicles located laterally in dorsal plane.
adults can shed 1 mill eggs a day.

Question 10

Diphyllobothrium latum host

Answer 10

def host: humans (fish eating mammals)

2 inter hosts:

1) copepod crustaceans
2) freshwater fish

Question 11

Diphyllobothrium latum life cycle

Answer 11

1. unembry. eggs passed in faeces
2. Eggs embroynate in water and hatch into Coracirdia they are ingested by copecod crustaceans+and in their body cavity procercoid larva
3. procercoid larva ingested by fish and migrate to muscles via bloodstream—>plercercoid larva
4. mammals eat infected fish, humans consume undercooked infected fish
5. adult worms develop in small intestine is immature eggs are passed in feces

Question 12

what is Taenia saginata known as?

Answer 12

beef taenia, taeniarhynchus sagiantus

Question 13

Taenia saginata morphology

Answer 13

5-10m, ribbon-like
scolex: 4 suckers, no rostellum- attachment to organ.
dorsoventrally flattened
gravid proglottid more than 12 uterine branches on each side

Question 14

Taenia saginata host

Answer 14

def host: humans ONLY
inter host: cattle

Question 15

Taenia saginata habitat

Answer 15

SI, jejunum

Question 16

Taenia saginata cause

Answer 16

taeniosis

Question 17

Taenia saginata transmission

Answer 17

eating raw or undercooked meat containing cysticercus bovis.

Question 18

Taenia saginata infective stage

Answer 18

Cysticercus bovis (larval stages)

Question 19

Taenia saginata + Taenia solium difference

Answer 19

gravid proglottid:
saginata: more than 12 uterine branches on each side
Solium: less than 12 uterine branches on each side

Scolex:
saginata: 4 suckers
Solium: 4 suckers, rostellum w/ 2 rows of hooks

Question 20

What is Taenia solium known as?

Answer 20

pork tenia

Question 21

Taenia solium cause

Answer 21

taeniosis,

cysticerci causes cysticerosis= in brain auto-infection

Question 22

Taenia solium habitat

Answer 22

SI

Question 23

Taenia solium morphology

Answer 23

3-4m, dorsoventrally flattened
scolex: 4 round suckers + rostellum w/ 2 rows of hook
neck: narrow, unsegmented
body: segmented, (I,M,G), mature proglottids ovary is 3 lobed.
gravid proglottids= less than 12 uterine branch on each side

Question 24

Taenia solium host

Answer 24

def host: Humans
inter host: pigs

Question 25

Taenia solium infective form

Answer 25

cysticercus

Question 26

Taenia solium transmission

Answer 26

Eating raw/undercooked meat containing cysticerci (cyst)

Question 27

Taenia solium transmission

Answer 27

- Eating raw/undercooked meat containing cysticerci (cyst) - auto infection- patient already has taeniosis. vomiting=brings gravid proglottids to stomach eggs and oncosphere released

Question 28

What is oncosphere?

Answer 28

6 hooked larval stage– attach + penetrate intestinal wall

Question 29

what is Hymenolepis nana known as?

Answer 29

dwarf tape worm, Taenia nana

Question 30

Hymenolepis nana cause

Answer 30

hymenolepasis

Question 31

Hymenolepis nana transmission

Answer 31

Ingestion of F/W contaminated with eggs Internal water infection – egg is released in intestine hatch there External autoinfection – person ingests own eggs by fecal-oral route

Question 32

Hymenolepis nana morphology

Answer 32

especially in children 40 mm > Scolex= 4 suckers and retractile rostellum w/single row of hooklets > neck= long slender > uterus= lobulated walls, 3 rounds testes

Question 33

Hymenolepis nana infective form

Answer 33

embryonate eggs

Question 34

Hymenolepis nana infective form

Answer 34

embryonated eggs

Question 35

Hymenolepis nana life cycle

Answer 35

1. eggs passed w/ feces 2. eggs ingested by Beetles 3. Eggs —>cysticercoids. when ingested rodents/ humans=infected 4. oncospheres hatch+develop into cysticercoids on intestinal walls. scolex forms, adult resides in ileum, SI. 5. gravid proglottids release eggs which is passed in stool. gravid can also disintegrate releasing eggs. 6. autoinfetion can occur if eggs remain in intestines. eggs releases embryo which penetrates the Vilius continuing the cycle. also, embryo. eggs ingested by humans from contaminated f/w=autoinfection

Question 36

Echinococcus granulosus habitat

Answer 36

jejunum+ duodenum of dogs

Question 37

why is Echinococcus granulosus most dangerous?

Answer 37

Can be infected by inhalation of parasite.

Question 38

what is Echinococcus granulosus known as?

Answer 38

dog tapeworm, hydatid tapeworm

Question 39

Echinococcus granulosus transmission

Answer 39

Ingesting F/W contaminated w/ dog feces, through direct contact with infected dog, can be inhaled herbivores infected by ingesting eggs

Question 40

Echinococcus granulosus cause

Answer 40

cystic echinococcosis= hyatid disease | enlarging cysts in organs

Question 41

Echinococcus granulosus host

Answer 41

``` def host: dogs inter host: herbivores animals (sheep, cattle) ```

Question 42

Echinococcus granulosus morphology

Answer 42

3–5 mm >Scolex: pear-shaped w/ 4 suckers+ rostellum w/ 2 rows of hooks >Neck = short >Strobila = 3 proglottids (I,M,G) eggs= ovoid, brown , 3 pairs of hooklets

Question 43

Echinococcus granulosus infective form

Answer 43

eggs

Question 44

Echinococcus granulosus life cycle

Answer 44

1. mbryonated eggs shed with feces 2. eggs ingested by herbivore,eggs hatch in SI—> oncosphere(6hooked larva). this penetrates intestinal wall,uses bloodstream to reach lungs and liver. 3. in organs, oncosphere developes into hydatid cyst(thick wall)(enlarges)—>protoscolex+ daugher cysts. 4. dogs become infected after ingesting cyst. 5. after ingestion scolex attatches to intestine.+ develop into adult stages.