Question

Assertion (A): In humans, filariasis is characterized by inflammation of the lower limbs.
Reason (R): Filarial worm usually lives in the lymphatic vessels of the lower limbs.

• A. ( \text{Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).}
• B. ( \text{Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).} )
• C. ( \text{Assertion (A) is true, but Reason (R) is false.} )
• D. ( \text{Assertion (A) is false, but Reason (R) is true.} )

Answer 1

The Correct Option is A

Filariasis, also known as elephantiasis, is a parasitic disease caused by filarial worms, such as \textit{Wuchereria bancrofti}. These worms commonly reside in the lymphatic vessels, particularly those of the lower limbs. Their presence obstructs the flow of lymph, leading to the accumulation of fluid and severe swelling, a condition known as lymphedema. This chronic lymphedema results in the thickening and hardening of the skin and underlying tissues, causing the characteristic inflammation and gross enlargement of the lower limbs seen in filariasis. Therefore, the assertion that filariasis is characterized by inflammation of the lower limbs is true, and the reason that the filarial worm usually lives in the lymphatic vessels of the lower limbs correctly explains this symptom.