Which statement best describes the function of the initial lymph capillary?

• A. Drain the deep lymphatics
• B. Move fluid to lymph nodes
• C. Lymph formation
• D. Prevent infections

Answer: (C)

The key idea is that initial lymph capillaries are the starting point of lymph formation. These blind-ended vessels have overlapping endothelial cells that act like mini valves. When tissue fluid builds up and interstitial pressure rises, these flaps open and fluid, along with proteins and small particles, can enter the capillaries. This uptake converts interstitial fluid into lymph, initiating the lymphatic transport that will move through larger collecting vessels toward lymph nodes and back into the venous system. So the best description is that their function is lymph formation. They aren’t primarily described as draining deep lymphatics or moving fluid directly to nodes, and while proper lymph formation supports immune surveillance, preventing infections isn’t their direct role.