parasitic worms in the lumen of intestine

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