Medical Parasitology Lecture: Intestinal and Tissue Nematodes, Flukes, and Tapeworms

A comprehensive set of vocabulary flashcards covering intestinal, tissue, and blood parasites including nematodes, trematodes, and cestodes as detailed in the lecture compilation.

Trichinella spiralis

A viviparous nematode that produces live young larvae; its diagnostic stage is the encysted larva found in the striated muscles.

Trichuris trichiura

Commonly called the Whipworm; characterized by a whip-like appearance with a thin anterior $\frac{3}{5}$ and a thick posterior $\frac{2}{5}$, and barrel-shaped eggs with bipolar mucoid plugs.

Capillaria philippinensis

Known as the Pudoc worm; its eggs are peanut-shaped with bipolar, non-protuberant mucus plugs and a thick, pitted shell that appears as striations.

Ancylostoma duodenale

The Old-world hookworm; its buccal capsule features two pairs of curved ventral (upper) teeth and the male has a tripartite dorsal ray in the bursa.

Necator americanus

The New world hookworm; it possesses a buccal capsule with 4 ventral cutting plates and a male bursa with a bipartite dorsal ray and long fused spicules.

Ancylostoma caninum

The American hookworm found primarily in dogs; its buccal capsule contains three pairs of ventral teeth, with the innermost being the smallest.

Enterobius vermicularis

Known as the Pinworm or Seatworm; the eggs are characteristically D-shaped (one side flat, one side curved) and are often recovered from perianal folds.

Ascaris lumbricoides

The Giant intestinal roundworm; characterized by three conspicuous lips (1 median dorsal, 2 ventro-lateral) and eggs that typically have a thick, mammillated albuminoid layer.

Strongyloides stercoralis filariform larva

The infective stage measuring about $550\,\mu\text{m}$ with a long, slender esophagus and a distinctive notched or forked caudal end.

Wuchereria bancrofti

The Bancroft’s filaria; the microfilaria stage has a hyaline sheath, a single stylet at the anterior end, and nuclei that do not extend to the tip of the tail.

Brugia malayi

A filarial worm where the microfilaria has double stylets at the anterior end and two discrete nuclei at the extreme tip of the tail.

Schistosoma japonicum

The Oriental blood fluke; found in the superior mesenteric veins, it produces ovoidal eggs ($70\text{--}100\,\mu\text{m} \times 50\text{--}65\,\mu\text{m}$) with a small lateral tubercle or spine.

Schistosoma mansoni

The cause of Manson’s schistosomiasis; found in the inferior mesenteric vein, its eggs are characterized by a prominent lateral spine.

Schistosoma haematobium

The Vesical blood fluke; inhabits the pelvic venous plexuses and is diagnosed by finding eggs in the urine.

Fasciola hepatica

The Sheep liver fluke; a large, leaf-shaped fluke ($3\,\text{cm} \times 1.5\,\text{cm}$) with a distinct conical projection called a cephalic cone at the anterior end.

Clonorchis sinensis

The Chinese Liver Fluke; produces flask-shaped, operculated eggs ($35\,\mu\text{m} \times 20\,\mu\text{m}$) with a terminal hook-like spine, resembling an electrical bulb.

Fasciolopsis buski

The Giant intestinal fluke; it is the largest intestinal fluke of man and lacks the cephalic cone seen in Fasciola species.

Echinostoma ilocanum

Garrison’s fluke; distinguished by an anterior circumoral disc surrounded by a crown of $49\text{--}51$ spines.

Heterophyes heterophyes

A minute intestinal fluke that possesses a third sucker called a genital sucker (gonotyl) situated on the left posterior border of the ventral sucker.

Paragonimus westermani

The Oriental lung fluke; lives in the lungs and head sinuses, producing golden brown, operculated eggs ($80\,\mu\text{m} \times 55\,\mu\text{m}$) with a flattened operculum.

Diphyllobothrium latum

The Fish tapeworm or Broad tapeworm; features a spatulate scolex with a pair of deep suction grooves called sulci and a rosette-like coiled uterus in mature proglottids.

Dipylidium caninum

The Double-pored or Dog tapeworm; its gravid proglottids are pumpkin seed-shaped and contains egg packets with $8\text{--}25$ eggs each.

Hymenolepis nana

The Dwarf tapeworm; produces spherical eggs ($30\text{--}45\,\mu\text{m}$) with an inner embryophore featuring polar filaments (4-8) originating from polar knobs.

Hymenolepis diminuta

The Rat tapeworm; produces larger, more circular eggs than H. nana that lack polar filaments, and an adult scolex with a rudimentary unarmed rostellum.

Taenia solium

The Pork tapeworm; its scolex is armed with a double row of $25\text{--}30$ hooklets and its gravid proglottids have fewer than 13 lateral uterine branches.

Taenia saginata

The Beef tapeworm; its scolex is unarmed (no rostellum or hooklets) and its gravid proglottids contain $12$ or more lateral uterine branches.

Echinococcus granulosus

The Hydatid tapeworm; a small worm (3-6 mm) with only 3 segments, whose larval stage is the Hydatid cyst found in hosts like man, sheep, and swine.