Final answer:
Elephantiasis is caused by the obstruction of lymphatic drainage, often due to parasitic worms, leading to chronic edema and tissue swelling in the extremities.
Step-by-step explanation:
Elephantiasis is caused by B. obstruction of lymphatic drainage. This blockage can lead to chronic edema, a condition where excess tissue fluid accumulates, usually in the extremities. It is often due to the presence of parasitic worms that obstruct the lymphatic vessels, causing swelling and enlargement of affected areas.
In addition to obstruction of lymphatic drainage, other causes of edema can include a decrease in plasma protein concentration, which lowers colloid osmotic pressure in the capillaries. However, the specific cause related to elephantiasis is the obstruction of lymphatic flow. Proper diagnosis and treatment of the underlying cause are essential for managing this condition.