Describe the life cycle of Ascaris lumbrice ids

Q. 07. Describe the life cycle of Ascaris lumbrice ids.
Life cycle of Acaris lumbricoids :-
1. The adult worm lives freely in the small intestine. The gravid female produces 200,000-250000 eggs daily. Freshly passed eggs are not infective to man.
2. The eggs become infective only when rihabilitiform larvae are hatched in the external environment by moulting. These take 3 to 4 weeks.
3. On ingestion the infective larva hatches out in the small intestine. The larva penetrates the intestinal wall to enter the portal circulation. It reaches the liver
4. From the liver it is carried to the right heart and via the pulmonary artery to the lungs.
5. In the lungs. It breaks out of the capillaries into the alveoli and moves up the bronchi and then crawls or the epiglottis to enter the digestive tract.
6. In the intestine, it moults for the fourth and last time to become an adult.
7. The lifespan of an adult worm is approximately 1 year after which it is expelled.