BIOL 3900 Lecture Notes - Lecture 8: Strongyloides Stercoralis, Trichuris Trichiura, Necator Americanus
Document Summary
Long oral cavity; also known as buccal cavity. Shell made up of a thick nitrogen-containing polysaccharide coating. Infective, nonfeeding stage that occurs after the rhabditiform larvae completes their second molt. Multicellular parasites that appear round in cross section. Infective pinworm eggs that migrate back into host body, develop, and reproduce rather than becoming dislodged. Average immature newly hatched hookworm characterized by the presence of a buccal cavity/capsule and a small genital primordium. Larvae: located inside the fertilized eggs; emerge and continue to mature. Adult worms: develop from the maturing larvae, sexes separate (females larger than males), equipped with a digestive and reproductive system. Intestinal nematode infection may be initiated in several ways. Fertilized adult female nematodes lay their eggs in the intestine and are then shed in the stool; they mature in the soil and infect a new host in 2-4 weeks. Most members have the ability to exist independent of a host.