Cestodes Adult Flashcards
long, tape-like, grayish yellow
measures 3-10 m in length and may have as many as 4, 000 proglottids
D latum
small and spatulate with a pair of deep suckers
measures 1 mm by 2.5 mm
neck region is attenuated and unsegmented which is several times the length of the head
D latum
Scolex
Male reproductive system consists of the minute spherical testes situated in the dorsolateral fields of the proglottids; from these, the vas deferens converge to form the seminal vesicle before terminating in the muscular organ that opens to the anterior side of the common genital pore
D latum
Mature
Female reproductive system consists of the dark rosette-like, coiled uterus in the mid-part of the proglottids, opens to the uterine pore a short distance behind the common genital pore; the ovary is symmetrically bilobed near the ventral surface in the posterior third above the Mehli’s gland; the vitellaria is situated in the lateral fields, converge to form the common vitelline duct, join the posterior end of the vagina which extends from the common genital pore
D latum
Mature
pale, reddish tape-like worm
measures 20 - 40 cm in length
D caninum
SCOLEX
small, rhomboid with a transverse diameter of 250 - 500u
provided with a retractile rostellum, armed with 3 or 4 rows of hooks shaped like rose thorns
there are 4 elliptical suckers
neck is short and thin
D caninum
MATURE SEGMENT
longer than broad, vase-like or pumpkin seed shaped
double set of reproductive organs and a genital pore on each lateral margin
seminal receptacle is lacking
uterus is sac-like, ovaries are bilobed and ovate
testes are spherical and are about 200 in number and occupy most of the available space median to the excretory canal
D caninum
GRAVID SEGMENT
pumpkin seed shaped like the mature segment and are filled with polygonal uterine blocks through the median field
each black or mother pocket contains 8-15 eggs enclosed in an embryonic membrane
D caninum
small, threadlike
measures 1-4 cm in length with a maximum diameter of 1mm
has 200 segments
H nana
SCOLEX
globular with 4 suckers
provided with retractile rostellum armed with a single row of hooklets numbering 20 -30 which are shaped like tuning forks
rostellum remains invaginated in the apex of the organ
neck is long
H nana
IMMATURE SEGMENT
short and narrow
genital primordial are already visible
MATURE SEGMENT
shorter than broad
GRAVID SEGMENT
after maturity all the reproductive organs except the cirral pouch, seminal receptacle and uterus disappear, so that the gravid segment will become a mere egg sac which hold 30 - 180 ova
H nana
threadlike flatworms
measures 10-60 mm in length and 4 cm in width has 800 - 1 000 segments
H diminuta
SCOLEX
small, club shape, measuring 0.2 - 0.4 mm
has a rudimentary apical unarmed rostellum has 4 small suckers
H diminuta
IMMATURE SEGMENT
short and narrow with visible genital primordial
MATURE SEGMENT
similar to H. nana
GRAVID SEGMENT
eggs in the uterus are clearly seen
other reproductive organs are not well differentiated
H diminuta
whitish or creamy white, tape-like worm
measures 2-5 m
has 800-1 000 segments
T solium
SCOLEX
globular in shape with 4 circular suckers
measures 1 mm in diameter (about the size of a pinhead)
has a rostellum armed with double row of 25-30 alternating large and small hooklets shaped like daggers
neck measures 5-10 mm in length
T solium
IMMATURE SEGMENT
small, wider than long
genital primordial can already be appreciated
MATURE SEGMENT
longer than broad
measures 12mm by 6 mm
common genital pore is marginal, thick lipped, situated near the middle on
the lateral margin of each segment, alternating irregularly between the right and left margins
T solium
MATURE SEGMENT
vaginal opening is not guarded by a muscular sphincter, vaginal tube ending internally into the ootype
ovary is situated in the posterior third of the segment and consists of 2 large symmetrical lobes and accessory lobe on the side of the genital pore
has 150-200 testicular follicles which are distributed throughout the dorsal plane
vas deferens proceeds are convoluted tubule to the genital atrium and enlarges to form the pars prostatica and the cirrus organ before reaching the genital atrium
GRAVID SEGMENT
the gravid uterus consists of a median longitudinal tube forming lateral branches when crowded with eggs
there are 7 - 13 (usually 9) lateral branches on each side of the main uterine trunk
T solium
white and semitransparent
measures 5 – 10 meters in length has 1000 – 2000 segments
T saginata
SCOLEX
quadrate, has 4 circular suckers (may be pigmented)
measures 1-2 mm in diameter not provided with any rostellum or hooklets neck is fairly long and narrow and is fragile
T saginata
IMMATURE SEGMENT
wider than long
genital primordial can be appreciated
MATURE SEGMENT
longer than broad, length being 3 - 4 times its breadth consecutive proglottids have irregularly alternate genital pores
excretory canal run though both sides of each segment
male genital system consists of the testes which 200 - 400 follicles, distributed throughout the dorsal plane
minute vas deferens from the testes join to form the convoluted vas deferens which courses laterally to the muscular cirrus organ which in turn opens into the common cup shaped genital atrium which forms a noticeable papillary projection on the lateral margins of the proglottids
dilated lower portion of the vas deferens is the seminal vesicle
T saginata
MATURE SEGMENT
the female genital system consists of the vagina which is straight tube coming from the common genital atrium often expanding to form the seminal receptacle
the follicular ovary usually bilobed is situated in the posterior part of the segment; from the ovary, the oviduct joins with the vitelline duct and enters the ootype which is surrounded by the Mehli’s gland
the uterus expands as a club shaped organ from the anterior surface of the ootype
T saginata
GRAVID SEGMENT
longer than broad
measures 1 - 2 cm in length and 0.5 cm in width
uterus when crowded with eggs will form lateral branches or extensions the uterus has no separate opening to the outside lateral branches of the gravid uterus is 12 or above
whole segment is occupied by the uterus and the rest of the genitalia disintegrates
T saginata
small tapeworm, measuring 3 - 6 mm in length it has 3 segments (occasionally 4)
E granulosus
SCOLEX
globular, measures 0.6 mm in breadth
has 4 prominent cup-like oval suckers
rostellum is protrusible with 2 circular rows (28 - 40 large and small hooklets)
neck is short and thick
E granulosus
IMMATURE SEGMENT
longer than broad
contains immature reproductive organs
MATURE SEGMENT
more elongated than the immature segment
has fully developed reproductive organs consisting of 43 - 65 pyrion
testes, mostly located anterior to the cirral sac, paired irregular ovaries in a posterior position and a single spherical vitelline gland
E granulosus
GRAVID SEGMENT
the biggest segment, measuring 2 -3 mm in length by 0.6 mm in breadth
it consists of a median uterus with 12 - 15 or more lateral pouches filed
with ova
lateral genital pore is equatorial or post-equatorial and is irregularly alternate
it is about half the length of the worm
E granulosus
