Zoology · Ch 7 — Human Health and Diseases
Helminthic diseases
Helminthic diseases
Helminthes (parasitic worms) mostly live as endoparasites in the human gut and blood, causing a group of diseases called helminthiasis. Two are highlighted here:
Ascariasis is caused by the intestinal roundworm Ascaris lumbricoides (Fig. 7.6), a monogenic parasite showing clear sexual dimorphism between the male and female worm. It spreads through ingestion of embryonated eggs in contaminated food and water, and children playing in contaminated soil are especially at risk of hand-to-mouth transfer. Symptoms include abdominal pain, vomiting, headache, anaemia, irritability and diarrhoea; heavy infections can cause nutritional deficiency, severe abdominal pain, stunted growth in children, and sometimes enteritis, hepatitis or bronchitis. …
What this figure shows. A labeled diagram of the roundworm Ascaris lumbricoides showing the triradiate mouth with lips, lateral line, excretory pore, penial setae, ventrally curved tail (male), cloacal aperture, and anus — illustrating the sexual dimorphism of this monogenic intestinal endoparasite that causes a …
What this figure shows. An illustrative figure of the thread-like filarial worm found in the human lymphatic system, showing its slender elongated body; the adult worms reside in lymph vessels and lymph nodes of man and give rise to juvenile microfilariae larvae that circulate and are picked up by the female Cule …
What this figure shows. A photographic figure showing elephantiasis, the gross swelling of the limbs caused by chronic obstruction of lymphatic vessels by accumulated adult Wuchereria bancrofti worms — a severe complication of long-standing filariasis that can also affect the scrotum and mammary glands. …