The lymphatic system is described as a separate vessel system that returns fluid to the bloodstream. Which statement is true?

• A. It is a separate vessel system that returns fluid to the bloodstream.
• B. It is part of the respiratory system.
• C. It transports oxygen in the blood.
• D. It digests lipids.

Answer: (A)

The main idea here is that the lymphatic system forms a separate network of vessels that collects fluid that leaks from capillaries and returns it to the bloodstream, helping to maintain circulating blood volume and support immune defense. Lymphatic vessels begin as tiny capillaries in tissues, carry the fluid as lymph through progressively larger vessels and lymph nodes, and drain into the venous system via the thoracic duct and the right lymphatic duct, returning it to the subclavian veins. It is distinct from the systems you hear about for breathing or digesting: the respiratory system handles gas exchange (not fluid return to blood), and digestion of lipids occurs in the GI tract (with absorbed fats traveling in lymph as chyle, not being digested by lymphatics). So describing the lymphatic system as a separate vessel system that returns fluid to the bloodstream is accurate.