Parasitology Flashcards: Trematodes, Cestodes, and Protozoa

Comprehensive vocabulary flashcards covering hepatic, intestinal, lung, and blood flukes, as well as medically and veterinarially important tapeworms and protozoa.

Dicrocoelium dendriticum

Commonly known as the lanceolate or lancet fluke, it is a bile duct parasite of domestic ruminants whose life cycle includes two intermediate hosts (snails and ants) and a final host.

Metacercariae

The infective stage of flukes like Dicrocoelium dendriticum and Clonorchis sinensis, formed when cercariae encyst in the second intermediate host or on vegetation.

Clonorchis sinensis

The Chinese liver fluke, a parasite that infects the common bile duct and gallbladder of fish-eating mammals and is a known risk factor for cholangiocarcinoma.

Cholangiocarcinoma

A neoplasm of the biliary system for which clonorchiasis (Clonorchis sinensis infection) is a known risk factor.

Paramphistomum cervi

A conical-shaped rumen fluke occurring in domestic animals throughout the world; its migrating juveniles cause severe enteritis and hemorrhage.

Fasciolopsis buski

A large, dorsoventrally flattened intestinal fluke characterized by a blunt anterior end and unbranched ceca, transmitted via the ingestion of aquatic plants.

Paragonimus westermani

The most common species of lung fluke to cause paragonimiasis, endemic in the Far East, North America, South America, and Africa.

Fasciola hepatica

Also known as the sheep liver fluke, it is a leaf-shaped parasite measuring approximately $3\text{ cm}$ in length that resides in the bile ducts of humans, sheep, and cattle.

Pipestem liver

A condition caused by Fasciola hepatica where inflammation and fibrosis result in a white appearance of the biliary ducts.

Schistosoma

A genus of blood flukes that are dioecious (separate sexes) and infect humans through direct skin penetration by cercariae in water.

Gynecophoral canal

A groove or canal formed by the ventral folding of the lateral margins of male Schistosoma flukes where the female is received.

Schistosoma mansoni

A blood fluke living in the inferior mesenteric venules that produces ellipsoidal eggs characterized by a lateral spine.

Schistosoma haematobium

A blood fluke living in the venous plexus of the urinary bladder that produces ellipsoidal eggs with a terminal spine, leading to hematuria.

Schistosoma japonicum

A blood fluke species living in the superior mesenteric venules that produces ovoidal or rounded eggs with a curved hook, spine, or lateral knob.

Echinococcus granulosus

A tapeworm causing cystic echinococcosis, which produces cystic lesions in definitive canine hosts and accidental human or herbivore intermediate hosts.

Oncosphere

The embryo contained within the eggs of tapeworms like Echinococcus, Moniezia, and Dipylidium caninum; it releases upon hatching in the host's stomach.

Diphyllobothrium latum

The broad or fish tapeworm, which can reach lengths of $2 \text{ to } 12\text{ meters}$ and is known for absorbing huge quantities of vitamin $B_{12}$, leading to anemia.

Dipylidium caninum

Also called the dog, cucumber, or flea tapeworm, it infects final hosts like dogs and cats through the ingestion of infected fleas or lice.

Moniezia expansa

A ruminant tapeworm that found in the small intestine of sheep and goats and requires oribatid mites as intermediate hosts.

Trypanosoma evansi

The causative agent of Surra disease, an acute infection in horses and chronic infection in camels, often transmitted mechanically by Tabanus flies.

Trypanosoma equiperdum

The causative agent of Dourine, a venereal disease of horses, donkeys, and mules characterized by genital edema and urticarial "Dollar spots."

Leishmania donovani

A protozoan parasite causing visceral leishmaniosis (Kala-azar or black fever), which is systemic and affects the liver and spleen.

Baghdad boil

A regional name for dry cutaneous leishmaniosis caused by Leishmania tropica, distributed in the Mediterranean and Middle East.

Amastigote form

The round, non-flagellated developmental stage of the family Trypanosomatidae found within the macrophages of the vertebrate host.

Tritrichomonas foetus

A venereal pathogen of cattle causing bovine trichomonal abortion, found in the uterus of cows and the preputial cavity of bulls.

Giardia lamblia

A bilaterally symmetrical protozoan with $8$ flagella and a large adhesive disc on its ventral surface used for attachment to intestinal epithelial cells.

Entamoeba histolytica

The protozoan cause of amebiasis, identified by trophozoites with food vacuoles containing red blood cells and cysts with up to four nuclei.

Eimeria tenella

A highly pathogenic species of Eimeria that infects the cecum of poultry, causing severe coccidiosis and bloody diarrhea.

Toxoplasma gondii

A zoonotic protozoan with felids as final hosts and mammals as intermediate hosts; it can cause abortion and occupies muscle, liver, lung, and brain tissues.

Babesia

An intra-erythrocytic parasite of domestic animals transmitted by hard ticks of the family Ixodidae, causing anemia and hemoglobinuria.

Koch's blue bodies

The schizont stage of Theileria parasites visualized within the lymphocytes in lymph nodes and blood.

Anaplasma marginale

A pathogenic rickettsial organism seen as small, dark red inclusion bodies located at the outer margin of cattle red blood cells.