Correct option: 2
Explanation: Internal valves are present in the lymphatic vessels. These valves prevent backflow of fluid, so that lymph flows forward and not falls backward.
Q37) Internal valves are present in the ________ . 1. Arterioles 2. lymphatic vessels 3. vascular capillaries 4. lymph capillaries
Q37) Internal valves are present in the ________ . 1. Arterioles 2. lymphatic vessels 3. vascular capillaries 4. lymph capillaries