(F) Trematodes: Introduction and Diecious Trematodes (moodle-based) Flashcards
- mostly are hermaphrodites
- may require one or more intermediate hosts
- can be divided in two, the monoecious flukes and the diecious flukes
Trematodes
Trematodes
Phylum
Platyhelminthes
Trematodes
- Cylindrical bodies
- Flattened or leaf-shaped bodies
- Only one inter-mediate host
- Produces non-operculate, embryonated eggs with miracidium
- Produces operculate eggs
A. Monoecious flukes
B. Diecious flukes
Pasagot po each no. thx
BABBA
Trematodes
Monoecious flukes need two intermediate hosts the first of which is almost always a species of?
snail
Trematodes
- Paragonimus westermani
- Schistosoma japonicum, S. mansoni and S. haematobium
- Fasciola hepatica, Clonorchis sinensis, Opistorchis felineus, O. viverrini
- Fasciolopsis buski, Echinostoma ilocanum, Heterophyes heterophyes, Haplorchis yokogawai, Metagonimus yokogawai
A. Blood Flukes
B. Intestinal Flukes
C. Lung fluke
D. Liver flukes
C, A, D, B
Trematodes
Flukes are generally provided with structures that are, except:
A. Nervous
B. Excretory
C. Circulatory
D. Digestive
E. Reproductive
C
Trematodes
- consists of a paired ganglion cells situated at the anterior part, at the back of the esophagus or pharynx, and nerve trunks that send fibers to the back, lateral, and ventral sides of the organism’s body
- consists of an oral cavity inside the oral sucker, which is continuous with the pre-pharyngeal tube, a muscular pharynx, esophagus, and two intestinal ceca with blind ends
- bilaterally symmetrical, which opens at the dorsal and posterior portion of the worm; flame cell
- described an inverted Y figure
A. Digestive
B. Excetory
C. Nervous
may na-repeat na answer
CABA
Trematodes
- Also known as solenocyte is the basic unit of the excretory apparatus
- joined by capillaries, which in turn are united forming the excretory tubules
Flame cell
Trematodes
Mode of excretion
regurgitation
wala nga sila anus kaya sa oral cavity uli ang daan
Trematodes
Foods of trematodes
- liquid and semi-liquid nutrients
gets from the environment
Trematodes
What happens to unused foods, as well as wastes?
regurgitated
Trematodes
If ever the worm needs oxygen, it is taken in via the?
skin
Trematodes
- hermaphrodite
- Female: has one ovary, an oviduct, ootype, multiple vitelline glands, seminal receptacle, Mehli’s glands, uterus, and genital pore
- Male: includes the testes, oftentimes paired in most species but multiple among blood flukes, vas efferens, vas deferens, seminal vesicle, ejaculatory duct, prostate glands, genital atrium, and a genital pore
- may produce either embryonated or immature eggs depending upon the species
Monoecious fluke
Trematodes
Stages of Development (pattern)
Egg – larva - adult
Trematodes: monoecious flukes
Infective stage to the snail host
dalawa
miracidium or egg to other molluscan or snail host
Trematodes:
The miracidium, once inside the snail (intermediate host) develops into a?
sporocyst
Trematodes:
- sac-like structure, with embryonic cells at the posterior part
- has a mouth with muscular pharynx, a blind and a non-forked cecum, a birth pore, and, in some species, locomotion organelles; released thru the birth pore
- the end-stage development in the snail host; a free-swimming, non-feeding larval stage, with penetration glands, attracted to light (phototaxis), and with a short life span
A. Cercaria
B. Redia
C. Sporocyst
CBA
ang development ay from miricidium -> sporocyst -> redia -> cercaria
Trematodes:
4 types of cercaria
(A) lophocercus or simple tail
(B) leptocercus or keel tailed
(C) microcercus
(D) furcocercus or fork-tailed
Trematodes:
- keel tailed, has a tubular tail with a thin membrane of the skin that serves as the rudder
- has no tail but instead provided with a small spherical appendage posteriorly
- has a tail that is bifurcated; found among diecious flukes
- simple tubular tail
(A) lophocercus
(B) leptocercus
(C) microcercus
(D) furcocercus or fork-tailed
BCDA
Trematodes:
How does the cercaria of monoecious flukes leaves the snail host?
death of the snail or overpopulation
Trematodes:
- swims in the water and finds the second intermediate host where it becomes encysted due to a fibrous capsule secreted by the intermediate host
- tail is cast off when it enters the body of the intermediate host
cercaria
Trematodes:
The encysted form, present among monoecious flukes, is called?
metacercaria
Trematodes: Diecious
infective stage to the definitive host
cercaria
Trematodes: Mono
infective form to the definitive host
metacercaria
Trematodes: Mono
MOT
ingestion of the metacercaria contained in the flesh of the second intermediate host
Trematodes: Mono
Ingested metacercaria undergoes excystation in the?
upper level of the small intestine
Trematodes: Diecious
MOT (mainly)
skin penetration
Cercaria may also be taken in orally through drinking water that is contaminated with the organism. However, the cercaria will still enter the surface area of the oral cavity to enter the circulation or lymphatics to reach their predilection site for maturity.
Trematodes: Diecious
- causing vesical schistosomiasis or urinary bilharziasis or schistosomal hematuria
- present in Africa (Sudan and Ethiopia), Central and West Africa, North Africa, West Asia (Lebanon, northern Syria, Arabia, Iraq, and Iran), and east coast of Africa (Malagasy, Mauritius, and Reunion)
- also found in India (Mumbai), Somalia, Tanzania, Zambia, and Angola.
Schistosoma haematobium