Question

Write the route of extraintestinal migration followed by the juveniles of Ascaris lumbricoides.

Answer 1

Ascaris lumbricoides is one of the most prevalent parasites occurring in the world that infect human. Humans are its definitive host. Females lay eggs in small intestine which are passed via faeces to soil. Before they became infective, they molt twice on the soil. After these eggs are ingested, juveniles emerge out which takes the route of extraintestinal migration. They travel through intestinal walls to hepatic vein and thoracic lymphatic duct and reach the lungs, from there they move to alveoli and ascend the tracheobronchial path to hypopharynx to get swallowed again. This is the extraintestinal migration of juveniles and they are returned to intestine to initiate another molt to change into an adult.