Morphology 令 No circulatory system s The reproductive system is in tubular form with dioecious(sex-differentiation) Digestive system cR The male reproductive organs are situated in the posterior third of the body 象/)交合 as a single coiled tube, the various parts 射精雪重殖腔 of which are differentiated as testis, vas male reproductive system deferens, seminal vesicle, and ejaculatory duct, also cloaca and spicule 受精 子宫 ca The female reproductive system may be 阴门阴遭 卵腐输所管 either a single or a bifurcated tube female reproductive system differentiated into ovary oviduct, seminal receptacle, uterus, ovejector and vagina
Morphology ❖ No circulatory system ❖ The reproductive system is in tubular form with dioecious (sex-differentiation): The male reproductive organs are situated in the posterior third of the body as a single coiled tube, the various parts of which are differentiated as testis, vas deferens, seminal vesicle, and ejaculatory duct, also cloaca and spicule The female reproductive system may be either a single or a bifurcated tube, differentiated into ovary, oviduct, seminal receptacle, uterus, ovejector and vagina 8 Digestive system female reproductive system male reproductive system
Physiology oo The methods of obtaining food may be classified as c& Sucking with ingestion of blood(Ancylostoma) cR Ingestion of lysed tissues and blood (trichuris c& Feeding on the intestinal contents(Ascaris) c& Ingestion of nourishment from the body fluids(filarial worms) .o Metabolism: mainly aerobic metabolism, and most species need free-living periods for larvae, which are capable of withstanding a wide range of environmental condition oo During larval development, nematodes pass through several molts or ecdysis, both inside and outside the host
Physiology ❖ The methods of obtaining food may be classified as Sucking with ingestion of blood (Ancylostoma) Ingestion of lysed tissues and blood (Trichuris) Feeding on the intestinal contents (Ascaris) Ingestion of nourishment from the body fluids (filarial worms) ❖ Metabolism: mainly aerobic metabolism, and most species need free-living periods for larvae, which are capable of withstanding a wide range of environmental condition ❖ During larval development, nematodes pass through several molts or ecdysis, both inside and outside the host 9
Life cycle ☆Geo- helminths cR Only one host: the larvae pass from host to host directly or after a free-living existence c& Transmission to a new host depends upon 'o the ingestion of the mature infectious eggs with larvae(Ascaris, Pinworm) .o the penetration of the skin or mucous membranes by the larvae(Hookworm) ☆Bio- helminths oR Have an intermediate host c& Transmission to a new definitive host is intermediated by the arthropod---(filarial worm) 10
Life cycle ❖ Geo-helminths Only one host: the larvae pass from host to host directly or after a free-living existence Transmission to a new host depends upon ❖ the ingestion of the mature infectious eggs with larvae (Ascaris, Pinworm) ❖ the penetration of the skin or mucous membranes by the larvae (Hookworm) ❖ Bio-helminths Have an intermediate host Transmission to a new definitive host is intermediated by the arthropod--- (filarial worm) 10
Common medical nematodes species go Intestinal lumen residing nematodes cR Ascaris, Hookworm, Whip worm, Pinworm----the adult parasite inhabit in human intestinal tract o Blood and tissue residing nematodes c& Filaria, Thichinella----the location of the adult parasite is blood or tissue
Common medical nematodes species ❖ Intestinal lumen residing nematodes: Ascaris, Hookworm, Whip worm, Pinworm----the adult parasite inhabit in human intestinal tract ❖ Blood and tissue residing nematodes: Filaria, Thichinella----the location of the adult parasite is blood or tissue 11
Ascaris lumbricoides (似蚓蛔线虫,蛔虫) 12
Ascaris lumbricoides (似蚓蛔线虫,蛔虫) 12