PRCC Microbiology Practice Exam

Ascaris lumbricoides, commonly known as the giant roundworm, has a complex life cycle that involves migration through different body systems. After ingestion of the eggs, the larvae hatch in the intestines and then penetrate the intestinal wall. From there, they enter the bloodstream and are carried to the lungs.

In the lungs, the larvae mature and undergo a stage of development where they also break into the alveoli. This phase is crucial as it allows for further growth and prepares the larvae for their eventual return to the digestive tract. They then migrate up the respiratory tract to the throat, where they are swallowed again, allowing them to return to the intestines to develop into adult worms.

This migratory behavior is a defining characteristic of Ascaris and is not an occurrence limited to severe cases or specifically tied to adult worms. Thus, the assertion that Ascaris larvae migrate to the lungs to mature before returning to the digestive tract is true. Understanding this life cycle is essential in grasping how these parasites establish infections and cause diseases in humans.