Which system collects waste products and transports lymph for excretion?

• A. Lymphatic System
• B. Excretory System
• C. Digestive System
• D. Respiratory System

Answer: (A)

The key idea is that the lymphatic system collects tissue fluid that leaks from blood vessels and converts it into lymph that travels through lymphatic vessels. This network gathers waste products from cells, moves them as lymph through lymph nodes and ducts, and returns the fluid to the bloodstream. By circulating this lymph, the body can remove cellular debris and transport immune cells, with the eventual disposal of wastes occurring as the fluid re-enters circulation and is processed by organs like the kidneys and liver for excretion. The other systems don’t primarily handle this lymph-transport role: the excretory system directly eliminates wastes via organs like the kidneys; the digestive system processes and expels solid and liquid wastes but doesn’t carry lymph; the respiratory system is focused on gas exchange.