(F) Cestodes: Differences of Pseudophyllidea from Cyclophyllidea (module-based) Flashcards
- flat and ribbon-like with white or yellowish color when alive
- Taxonomically, this has two orders, namely Pseudophyllidea and Cyclophyllidea
- consists of a chain of egg producing units called segments or proglottids
Cestodes
consists of a chain of egg producing units
Segments or Proglottids
series of segments
Strobila
important structures (2), since infection persists as long as these parts remain attached to the host’s intestinal wall, even though the greater portion of the strobila may have become free and evacuated
Scolex and neck
CESTODES
TOF. Typically, the adult is in the middle portion of the small intestine of its host.
T
serves as an anchor structure and for orientation of the strobila
part
scolex or head
- behind scolex
- serves as the growth region
- where segments originate
Neck
Segments may be classified as?
immature, mature and gravid
This are the ones that detach and come with the stool or disintegrate.
anong portion ng gravid proglottids
terminal portions of the gravid proglottids
Match: Classification
- Larger units, each of which contains full set of male and female genital organs Follows the first segment
- Farthest from the scolex whose primary genitals are reduced or atrophied due to the enlarged uterus containing numerous eggs
- Segments develop from the distal end of the neck where units are just differentiating and where the sexual organs are still developing
A. Immature
B. Mature
C. Gravid
D. Intermediate
BCA
Detachment of segments can occur singly or in series. The lost segments will be replenished by the?
what body part
neck
by growing immature segments to replace the lost ones
Match
- Broad and wide; Common atrium (genital and uterine pore) at the median of the ventral side, uterus inside is piled, coiled or rosette at the midline.
- Transversely quadrate/rhomboid with 4 cup- like suckers, may or may not have rostellum, which may or may not have spines or hooks and, if with hooks it is referred as armed scolex
- Longer and has lateral genital pore; Atrium (genital pore only) at the lateral margins, which may be on the same side or alternate. Uterus is tubular, which may end blindly; has 2 atriums
- Narrow, spindle, or spoon shaped with an elongate groove at mid- ventral side called bothria or suctorial groove or sula
A. Scolex (Pseudophyllidea)
B. Scolex (Cyclophyllidea)
C. Mature Segment (P)
D. Mature Segment (C)
CBDA
- More concentrated at the center; Uterus is engorged with eggs causing segment to be much bigger and tends to be oval- shaped. Other structures atrophy
- Spherical, non-operculate and almost fully matured when released from the segments.
- Oval-shaped, operculate and immature when laid.
- Uterus develops several lateral branches, filled-up with eggs causing the segment much bigger and thicker than the mature proglottid.
A. Gravid segment (P)
B. Gravid segment (C)
C. Egg (P)
D. Egg (C)
E. NOTA
ADCB
- Coracidium – ciliated embryo
- Embryophore – ciliated
- Occurs in the water
- Occurs after ingested by the appropriate host
A. Hatching (P)
B. Hatching (C)
C. Embryo (P)
D. Embryo (C)
E. NOTA
C
E (should be non-ciliated)
A
B
Fully embryonated egg contains an oncosphere (hooked ball), which has 3 pairs of hooklets (thus called?
“hexacanth embryo”
Larvae of Tapeworms
- can be globular or elongate with an invaginated scolex inside its solid body and with a vestige of the embryo with hooklets, called cercomere, situated at the caudal part.
Procercoid (P)
Larvae of Tapeworms
elongate with scolex, which may either be invaginated or free into the neck part of the larvae and may look like a miniature of the adult worm with markings of the would be adult.
Plerocercoid or sparganum (P)
Larvae of Tapeworms
Procercoid can be globular or elongate with an invaginated scolex inside its solid body and with a vestige of the embryo with hooklets, called?
cercomere (P)
Larvae of Tapeworms
with a single scolex invaginated into the proximal portion of the large bladder
Cysticercus (C)
Larvae of Tapeworms
has a small body at the anterior part with an invaginated scolex within the cavity and a solid elongate caudal portion.
Cysticercoid (C)
Larvae of Tapeworms
is globular-shaped, with the shell of which has an inner layer of germinal epithelium where protoscolices arises, which in turn are projected into the fluid-filled cavity. The fluid inside is very potent anaphylatoxin.
Coenurus (C)
Larvae of Tapeworms
is globular- shaped with the germinal epithelium giving rise to smaller daughter cysts within the fluid-filled cavity, which in turn giv rise to protoscolices. Detached daughter cyst (brood capsule) produces small cysts within, which will have the protoscolices. Similar with coenurus, the fluid content of hydatid is a very potent anaphylatoxin
Hydatid or Echinococcus (C)
Match Larvae of Tapeworms
- Sparganum
- Echinococcus
- Cysticercoid
- Procercoid
- Coenurus
A. Solid larvae
B. Vesicular Larvae
A, B, B, A, B
Internal Structures
consists of a ganglion cell located inside the mid-part of the scolex with nerve fibers going up and downward to the rest of the strobila.
Nervous
Internal Structures
starts with solenocytes (flame cells) scattered within the segment, each of which is joined with the others with a capillary, which in turn joins together to form collecting tubules that drain in a canal system consisting of longitudinal canals on the sides of the segments interconnected with transverse canals on the upper- and lower part of each segment. The end part of the longitudinal canals, at the terminal segment, serves as the excretory pore.
Excretion
Internal Structures
each segment is considered a reproductive unit, particularly the mature segment, which contains the uterus at the mid portion, ovaries at the base of the uterus, and vitelline glands below
Reproduction
Internal Structures
there is no specific structure within the segment that serves as digestive tract and nutrition is through absorption of nutrients
Digestion
Internal Structures: Excretion
he end part of the longitudinal canals, at the terminal segment, serves as the?
excretory pore
Internal Structures: Reproduction
each segment is considered a reproductive unit, particularly the mature segment which contains:
1. Uterus
2. Ovaries
3. Vitelline glands
A. base
B. mid portion
C. below
match their loc
BAC
Internal Structures: Reproduction
Secrete ground substance for the eggshell
Vitelline glands
Internal Structures: Reproduction
are scattered within the same segment and thus, tapeworms are regarded as hermaphrodite
Testicular follicles
Internal Structures: Digestion
nutrition is through absorption of nutrients via the?
Skin of the entire worm, which is provided with microtriches
Internal Structures: Digestion
simulating intestinal villi of higher form of animals
microtriches
Clinical Aspect of Tapeworm Infection
This stage is likely to produce serious conditions because the larvae may be lodged in critical foci such as the brain, eyes, or elsewhere in the body and may grow to large masses producing pressure defects on adjacent structures, such as with coenurus and hydatid larvae infections.
Larval
Clinical Aspect of Tapeworm Infection
when ruptured in situ, can lead to anaphylaxis or toxicity, since the fluid content is a potent anaphylatoxin capable of causing shock.
type of larvae
coenurus and hydatid
