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Flashcards in Lab 8 Deck (42)
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1
Q

-the “head” region of the tapeworm

A

SCOLEX

2
Q

scolex is equipped with some sort of holdfast organ – some variations include:

A

1) suckers 2) hooks 3) grooves

3
Q

-the types of sucker-like organs on scolices of cestodes that infect man:

A

1) Acetabula (sing. acetabulum)

2) Bothria

4
Q

Acetabula (sing. acetabulum)

  • _____ or ______shaped with muscular wall
  • usual pattern:
A
  • circular or oval cup

- 4 equally spaced around scolex

5
Q

Bothria
Shape:
Usually __ in number
-________ location on scolex

A
  • “Slit-like” shallow pits or long grooves
  • 2
  • Lateral or dorsoventral
6
Q

protruding dome-shaped area on anterior end of scolex

A

Rostellum

7
Q
  • “armed” -

- “unarmed” -

A
  • hooks are arranged on it This is the rule.

- no hooks

8
Q

(presence and absence of ______ and shape and arrangement of _____
are identification keys in cestodes)

A
  • rostellum

- hooks

9
Q

region between scolex and strobila segments

A

neck

10
Q

contains stem cells that give rise to new proglottids

A

neck

11
Q

long chain of proglottids (segments)

depending upon species, from a few to thousands of proglottids

A

strobila

12
Q

Strobila

-each has sets of reproductive organs of ____ -“_____” in each set

A
  • both sexes

- genitalium

13
Q

growth of strobila is called:

A

strobilization

14
Q

strobilization occurs from _____ end as new proglottids are added

A

anterior

15
Q

proglottids closest to scolex –

A

most immature

16
Q

“gravid” =

A

filled with eggs

17
Q

proglottids in strobila “_____fertilize” (rarely self-copulate within same proglottid)

A

-cross

18
Q

How proglottids are shed: depends upon:

A

species of cestode

19
Q

3 ways proglottids are shed:

A
  1. intact gravid
  2. proglottid disentigrates as shed and eggs go out with feces
  3. eggs shed from attached proglottid through uterine pore
20
Q

-means an empty, formerly gravid proglottid

A

“Senile”

21
Q

Tegument is important in: (3)

A
  1. absorption (cestodes dont have GI tract)
  2. excretion of wastes
  3. osmoregulation
22
Q

how does tegument effectively absorb nutrients?

A

-covered in microvilli called “microtriches” even on the suckers – increases
the absorptive area of tegument

23
Q

MUSCULAR SYSTEM:

  • each proglottid has two layers of muscle:
  • enables each segment to:
A
  • longitudinal, transverse

- move independently

24
Q

NERVOUS SYSTEM:

  • well developed in cestodes
  • sensory: ____receptive, _____receptive
A

-tacto, chemo

25
Q

Which is rare in cestodes? monecious or dioecious?

A

dioecious

26
Q

dioecious cestodes do not infect:

A

man or his domestic animals

27
Q

______ reproduction is the Rule in cestodes

A

MONECIOUS

28
Q

-cestode fertilization occurs when repro systems ______

A

mature (as proglottids proceed toward posterior part of strobila)

29
Q

-self-mating within the same proglottid is the _____, not the ____.

A

-exception, rule

30
Q

sperm are transferred between:

A

mature proglottids that lie next to each other in intestine of definitive host

31
Q

-gravid proglottids – contain _____# of eggs

A

100’s to 1000’s

32
Q

2 different types of cestode egg shells?

A

Dipylidium type, taenia type

33
Q

Which type of egg shell is thin?

A

Dipylidium

34
Q

Which type of egg shell is thick?

A

Taenia

35
Q

Taenia type egg shell contain a _______ embryo within

A

hexacanth

36
Q

which species have a dipylidium type shell?

A

Diphyllobothrium latum
Dipylidium caninum
Hymenolepsis nana and H. diminuta

37
Q

which species have a taenia type shell?

A

Taenia sp., Echinococcus sp.

38
Q

-Most cestodes require minimum of two hosts for completion of cycle. There is always an exception:
________ can complete life cycle in same host.
– ________ host is optional for H. nana

A
  • Hymenolepsis nana

- Invertebrate intermediate

39
Q

Cestode life span depends on species, but can last from _____ to _____

A

days, years

40
Q

_______ -the hexacanth larva in the egg

A

ONCOSPHERE

41
Q

________- juvenile (larval) form of tapeworm found in intermediate hosts

A

METACESTODE:

42
Q

general life cycle of cestodes

A

egg –�oncosphere (in egg) �– metacestode (in intermediate host)� –adult worm (in definitive host)