parasitic worms in the lumen of intestine

ancylostoma animal ascariasis ascarid ascaris biological biology bowel caninum closeup disease dog duodenale enterobius giant gut health helminth hook hookworm human illustration infection infestation intestine large lumbricoides lumen medical medicine microbiology microscope nature neglected nematoda parasite parasitic pinworm research roundworm science small trichinella trichiura trichuris vermicularis whipworm worm zoology